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Gutiérrez-Casares JR, Quintero J, Segú-Vergés C, Rodríguez Monterde P, Pozo-Rubio T, Coma M, Montoto C. In silico clinical trial evaluating lisdexamfetamine's and methylphenidate's mechanism of action computational models in an attention-deficit/hyperactivity disorder virtual patients' population. Front Psychiatry 2023; 14:939650. [PMID: 37333910 PMCID: PMC10273406 DOI: 10.3389/fpsyt.2023.939650] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/09/2022] [Accepted: 04/21/2023] [Indexed: 06/20/2023] Open
Abstract
Introduction Attention-deficit/hyperactivity disorder (ADHD) is an impairing psychiatric condition with the stimulants, lisdexamfetamine (LDX), and methylphenidate (MPH), as the first lines pharmacological treatment. Methods Herein, we applied a novel in silico method to evaluate virtual LDX (vLDX) and vMPH as treatments for ADHD applying quantitative systems pharmacology (QSP) models. The objectives were to evaluate the model's output, considering the model characteristics and the information used to build them, to compare both virtual drugs' efficacy mechanisms, and to assess how demographic (age, body mass index, and sex) and clinical characteristics may affect vLDX's and vMPH's relative efficacies. Results and Discussion We molecularly characterized the drugs and pathologies based on a bibliographic search, and generated virtual populations of adults and children-adolescents totaling 2,600 individuals. For each virtual patient and virtual drug, we created physiologically based pharmacokinetic and QSP models applying the systems biology-based Therapeutic Performance Mapping System technology. The resulting models' predicted protein activity indicated that both virtual drugs modulated ADHD through similar mechanisms, albeit with some differences. vMPH induced several general synaptic, neurotransmitter, and nerve impulse-related processes, whereas vLDX seemed to modulate neural processes more specific to ADHD, such as GABAergic inhibitory synapses and regulation of the reward system. While both drugs' models were linked to an effect over neuroinflammation and altered neural viability, vLDX had a significant impact on neurotransmitter imbalance and vMPH on circadian system deregulation. Among demographic characteristics, age and body mass index affected the efficacy of both virtual treatments, although the effect was more marked for vLDX. Regarding comorbidities, only depression negatively impacted both virtual drugs' efficacy mechanisms and, while that of vLDX were more affected by the co-treatment of tic disorders, the efficacy mechanisms of vMPH were disturbed by wide-spectrum psychiatric drugs. Our in silico results suggested that both drugs could have similar efficacy mechanisms as ADHD treatment in adult and pediatric populations and allowed raising hypotheses for their differential impact in specific patient groups, although these results require prospective validation for clinical translatability.
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Affiliation(s)
- José Ramón Gutiérrez-Casares
- Unidad Ambulatoria de Psiquiatría y Salud Mental de la Infancia, Niñez y Adolescencia, Hospital Perpetuo Socorro, Badajoz, Spain
| | - Javier Quintero
- Servicio de Psiquiatría, Hospital Universitario Infanta Leonor, Universidad Complutense, Madrid, Spain
| | - Cristina Segú-Vergés
- Anaxomics Biotech, Barcelona, Spain
- Structural Bioinformatics Group, Research Programme on Biomedical Informatics, Department of Medicine and Life Sciences, Universitat Pompeu Fabra, Barcelona, Spain
| | | | | | | | - Carmen Montoto
- Medical Department, Takeda Farmacéutica España, Madrid, Spain
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Daubner J, Arshaad MI, Henseler C, Hescheler J, Ehninger D, Broich K, Rawashdeh O, Papazoglou A, Weiergräber M. Pharmacological Neuroenhancement: Current Aspects of Categorization, Epidemiology, Pharmacology, Drug Development, Ethics, and Future Perspectives. Neural Plast 2021; 2021:8823383. [PMID: 33519929 PMCID: PMC7817276 DOI: 10.1155/2021/8823383] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2020] [Revised: 12/15/2020] [Accepted: 12/30/2020] [Indexed: 11/17/2022] Open
Abstract
Recent pharmacoepidemiologic studies suggest that pharmacological neuroenhancement (pNE) and mood enhancement are globally expanding phenomena with distinctly different regional characteristics. Sociocultural and regulatory aspects, as well as health policies, play a central role in addition to medical care and prescription practices. The users mainly display self-involved motivations related to cognitive enhancement, emotional stability, and adaptivity. Natural stimulants, as well as drugs, represent substance abuse groups. The latter comprise purines, methylxanthines, phenylethylamines, modafinil, nootropics, antidepressants but also benzodiazepines, β-adrenoceptor antagonists, and cannabis. Predominant pharmacodynamic target structures of these substances are the noradrenergic/dopaminergic and cholinergic receptor/transporter systems. Further targets comprise adenosine, serotonin, and glutamate receptors. Meta-analyses of randomized-controlled studies in healthy individuals show no or very limited verifiability of positive effects of pNE on attention, vigilance, learning, and memory. Only some members of the substance abuse groups, i.e., phenylethylamines and modafinil, display positive effects on attention and vigilance that are comparable to caffeinated drinks. However, the development of new antidementia drugs will increase the availability and the potential abuse of pNE. Social education, restrictive regulatory measures, and consistent medical prescription practices are essential to restrict the phenomenon of neuroenhancement with its social, medical, and ethical implications. This review provides a comprehensive overview of the highly dynamic field of pharmacological neuroenhancement and elaborates the dramatic challenges for the medical, sociocultural, and ethical fundaments of society.
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Affiliation(s)
- Johanna Daubner
- Experimental Neuropsychopharmacology, Federal Institute for Drugs and Medical Devices (Bundesinstitut für Arzneimittel und Medizinprodukte, BfArM), Kurt-Georg-Kiesinger-Allee 3, 53175 Bonn, Germany
| | - Muhammad Imran Arshaad
- Experimental Neuropsychopharmacology, Federal Institute for Drugs and Medical Devices (Bundesinstitut für Arzneimittel und Medizinprodukte, BfArM), Kurt-Georg-Kiesinger-Allee 3, 53175 Bonn, Germany
| | - Christina Henseler
- Experimental Neuropsychopharmacology, Federal Institute for Drugs and Medical Devices (Bundesinstitut für Arzneimittel und Medizinprodukte, BfArM), Kurt-Georg-Kiesinger-Allee 3, 53175 Bonn, Germany
| | - Jürgen Hescheler
- Institute of Neurophysiology, University of Cologne, Faculty of Medicine, Robert-Koch-Str. 39, 50931 Cologne, Germany
| | - Dan Ehninger
- Molecular and Cellular Cognition, German Center for Neurodegenerative Diseases (Deutsches Zentrum für Neurodegenerative Erkrankungen, DZNE), Sigmund-Freud-Str. 27, 53127 Bonn, Germany
| | - Karl Broich
- Federal Institute for Drugs and Medical Devices (Bundesinstitut für Arzneimittel und Medizinprodukte, BfArM), Kurt-Georg-Kiesinger-Allee 3, 53175 Bonn, Germany
| | - Oliver Rawashdeh
- School of Biomedical Sciences, Faculty of Medicine, University of Queensland, Brisbane, Australia
| | - Anna Papazoglou
- Experimental Neuropsychopharmacology, Federal Institute for Drugs and Medical Devices (Bundesinstitut für Arzneimittel und Medizinprodukte, BfArM), Kurt-Georg-Kiesinger-Allee 3, 53175 Bonn, Germany
| | - Marco Weiergräber
- Experimental Neuropsychopharmacology, Federal Institute for Drugs and Medical Devices (Bundesinstitut für Arzneimittel und Medizinprodukte, BfArM), Kurt-Georg-Kiesinger-Allee 3, 53175 Bonn, Germany
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3
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van Atteveldt N, Tijsma G, Janssen T, Kupper F. Responsible Research and Innovation as a Novel Approach to Guide Educational Impact of Mind, Brain, and Education Research. MIND, BRAIN AND EDUCATION : THE OFFICIAL JOURNAL OF THE INTERNATIONAL MIND, BRAIN, AND EDUCATION SOCIETY 2019; 13:279-287. [PMID: 31749892 PMCID: PMC6867903 DOI: 10.1111/mbe.12213] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
We propose a Responsible Research and Innovation (RRI) framework to improve the alignment between mind, brain, and education (MBE) research, the educational practice, and other societal stakeholders. RRI is an approach that has successfully been used in different research fields, but not yet in MBE research. After substantiating the need for, and possibilities of using this framework within MBE research, we report a case study to demonstrate the feasibility and benefits of RRI within an MBE context. This case study entails developing an educational intervention to improve learners' sense of agency regarding their own learning processes using neurofeedback. Using RRI, we found that societal stakeholders (teenagers, parents, and teachers) anticipate different potential impacts of this neurotechnology-based intervention than researchers did, enabling us to adapt the intervention according to these perspectives. This example demonstrates that RRI enables researchers to be reflexive and responsive to the stakeholders needs and values, to ultimately improve the educational and societal value of MBE research.
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Affiliation(s)
- Nienke van Atteveldt
- Faculty of Behavioural and Movement Sciences, Section of Clinical Developmental Psychology and Institute Learn!Vrije Universiteit Amsterdam
| | - Geertje Tijsma
- Faculty of Beta Sciences, Athena InstituteVrije Universiteit Amsterdam
| | - Tieme Janssen
- Faculty of Behavioural and Movement Sciences, Section of Clinical Developmental Psychology and Institute Learn!Vrije Universiteit Amsterdam
| | - Frank Kupper
- Faculty of Beta Sciences, Athena InstituteVrije Universiteit Amsterdam
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4
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Berta B, Kertes E, Péczely L, Ollmann T, László K, Gálosi R, Kállai V, Petykó Z, Zagorácz O, Kovács A, Karádi Z, Lénárd L. Ventromedial prefrontal cortex is involved in preference and hedonic evaluation of tastes. Behav Brain Res 2019; 367:149-157. [PMID: 30940513 DOI: 10.1016/j.bbr.2019.03.051] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2019] [Revised: 03/29/2019] [Accepted: 03/29/2019] [Indexed: 01/01/2023]
Abstract
The ventromedial prefrontal cortex (vmPFC) of rats has reciprocal connections with the gustatory and the hedonic impact coding structures. The main goal of the present study was to investigate the involvement of local neurons of vmPFC and their catecholaminergic innervations in taste preference and taste reactivity test. Therefore, kainate or 6-hydroxydopamine (6-OHDA) lesions were performed in the vmPFC by iontophoretic method. In the first experiment, taste preference was tested to 250 mM and 500 mM glucose solutions over water in two-bottle choice test. In the second experiment, taste reactivity was examined to 4 concentrations of glucose solutions (250 mM, 500 mM, 750 mM and 1000 mM) and 4 concentrations of quinine solutions (0.125 mM, 0.25 mM, 1.25 mM and 2.5 mM). Our results showed, that kainate microlesion of vmPFC did not modify the preference of 250 mM and 500 mM glucose solutions in two-bottle choice test. In contrast, 6-OHDA microlesion of vmPFC resulted in increased preference to the higher concentration of glucose (500 mM) solution over water. Results of taste reactivity test showed that kainate lesion resulted in more ingestive and less rejective responses to 750 mM glucose solution and elevated rejectivity to the higher concentrations (1.25 mM and 2.5 mM) of quinine solutions. 6-OHDA lesion of vmPFC increased the number of ingestive responses to highly concentrated (500 mM, 750 mM and 1000 mM) glucose solutions and decreased the number of ingestive responses to the lower concentration (0.125 mM) of quinine solution. The present data provide evidence for the important role of vmPFC neurons and catecholaminergic innervation of the vmPFC in the regulation of hedonic evaluation of tastes and in the hedonic consummatory behavior.
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Affiliation(s)
- Beáta Berta
- Institute of Physiology, Medical School, Pécs University, Pécs, Hungary; Neuroscience Center, Pécs University, Pécs, Hungary
| | - Erika Kertes
- Institute of Physiology, Medical School, Pécs University, Pécs, Hungary; Neuroscience Center, Pécs University, Pécs, Hungary
| | - László Péczely
- Institute of Physiology, Medical School, Pécs University, Pécs, Hungary; Neuroscience Center, Pécs University, Pécs, Hungary
| | - Tamás Ollmann
- Institute of Physiology, Medical School, Pécs University, Pécs, Hungary; Neuroscience Center, Pécs University, Pécs, Hungary
| | - Kristóf László
- Institute of Physiology, Medical School, Pécs University, Pécs, Hungary; Neuroscience Center, Pécs University, Pécs, Hungary
| | - Rita Gálosi
- Institute of Physiology, Medical School, Pécs University, Pécs, Hungary; Neuroscience Center, Pécs University, Pécs, Hungary
| | - Veronika Kállai
- Institute of Physiology, Medical School, Pécs University, Pécs, Hungary; Neuroscience Center, Pécs University, Pécs, Hungary
| | - Zoltán Petykó
- Institute of Physiology, Medical School, Pécs University, Pécs, Hungary; Neuroscience Center, Pécs University, Pécs, Hungary; Molecular Neuroendocrinology Research Group, Szentágothai Research Center, Pécs University, Pécs, Hungary
| | - Olga Zagorácz
- Institute of Physiology, Medical School, Pécs University, Pécs, Hungary; Neuroscience Center, Pécs University, Pécs, Hungary
| | - Anita Kovács
- Institute of Physiology, Medical School, Pécs University, Pécs, Hungary; Neuroscience Center, Pécs University, Pécs, Hungary
| | - Zoltán Karádi
- Institute of Physiology, Medical School, Pécs University, Pécs, Hungary; Neuroscience Center, Pécs University, Pécs, Hungary; Molecular Neuroendocrinology Research Group, Szentágothai Research Center, Pécs University, Pécs, Hungary
| | - László Lénárd
- Institute of Physiology, Medical School, Pécs University, Pécs, Hungary; Neuroscience Center, Pécs University, Pécs, Hungary; Molecular Neuroendocrinology Research Group, Szentágothai Research Center, Pécs University, Pécs, Hungary.
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Busardò FP, Kyriakou C, Cipolloni L, Zaami S, Frati P. From Clinical Application to Cognitive Enhancement: The Example of Methylphenidate. Curr Neuropharmacol 2016; 14:17-27. [PMID: 26813119 PMCID: PMC4787280 DOI: 10.2174/1570159x13666150407225902] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2015] [Revised: 03/17/2015] [Accepted: 04/03/2015] [Indexed: 12/20/2022] Open
Abstract
Methylphenidate (MPD) is a central nervous system (CNS) stimulant, which belongs to the phenethylamine group and is mainly used in the treatment of attention deficit hyperactive disorder (ADHD). However, a growing number of young individuals misuse or abuse MPD to sustain attention, enhance intellectual capacity and increase memory. Recently, the use of MPD as a cognitive enhancement substance has received much attention and raised concerns in the literature and academic circles worldwide. The prescribing frequency of the drug has increased sharply as consequence of the more accurate diagnosis of the ADHD and the popularity of the drug itself due to its beneficial short-term effect. However, careful monitoring is required, because of possible abuse. In this review different aspects concerning the use of MPD have been approached. Data showing its abuse among college students are given, when the drug is prescribed short term beneficial effects and side effects are provided; moreover studies on animal-models suggesting long lasting negative effects on healthy brains are discussed. Finally, emphasis is given to the available formulations and pharmacology.
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Affiliation(s)
- Francesco Paolo Busardò
- Department of Anatomical, Histological, Medico-legal and Orthopaedic Sciences, Sapienza University of Rome, Viale Regina Elena 336 (00185) Rome, IT.
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Wang JJ, Odic D, Halberda J, Feigenson L. Changing the precision of preschoolers' approximate number system representations changes their symbolic math performance. J Exp Child Psychol 2016; 147:82-99. [PMID: 27061668 DOI: 10.1016/j.jecp.2016.03.002] [Citation(s) in RCA: 49] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2015] [Revised: 01/31/2016] [Accepted: 03/07/2016] [Indexed: 01/29/2023]
Abstract
From early in life, humans have access to an approximate number system (ANS) that supports an intuitive sense of numerical quantity. Previous work in both children and adults suggests that individual differences in the precision of ANS representations correlate with symbolic math performance. However, this work has been almost entirely correlational in nature. Here we tested for a causal link between ANS precision and symbolic math performance by asking whether a temporary modulation of ANS precision changes symbolic math performance. First, we replicated a recent finding that 5-year-old children make more precise ANS discriminations when starting with easier trials and gradually progressing to harder ones, compared with the reverse. Next, we show that this brief modulation of ANS precision influenced children's performance on a subsequent symbolic math task but not a vocabulary task. In a supplemental experiment, we present evidence that children who performed ANS discriminations in a random trial order showed intermediate performance on both the ANS task and the symbolic math task, compared with children who made ordered discriminations. Thus, our results point to a specific causal link from the ANS to symbolic math performance.
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Affiliation(s)
- Jinjing Jenny Wang
- Department of Psychological and Brain Sciences, Johns Hopkins University, Baltimore, MD 21218, USA.
| | - Darko Odic
- Department of Psychological and Brain Sciences, Johns Hopkins University, Baltimore, MD 21218, USA
| | - Justin Halberda
- Department of Psychological and Brain Sciences, Johns Hopkins University, Baltimore, MD 21218, USA
| | - Lisa Feigenson
- Department of Psychological and Brain Sciences, Johns Hopkins University, Baltimore, MD 21218, USA
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7
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Asbrand J, Lerach T, Tuschen-Caffier B. Störungstypische Erziehungsfaktoren bei Aufmerksamkeits- und Angststörungen im Kindes- und Jugendalter. ZEITSCHRIFT FUR KLINISCHE PSYCHOLOGIE UND PSYCHOTHERAPIE 2015. [DOI: 10.1026/1616-3443/a000329] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
Zusammenfassung. Theoretischer Hintergrund: Die Erziehungsfaktoren Negativität und Kontrolle werden sowohl im Zusammenhang mit der Aufmerksamkeits-Defizit-Hyperaktivitäts-Störung (ADHS) als auch mit Angststörungen (AS) diskutiert. Fragestellung: Unklar ist bislang, ob ADHS und AS gleichermaßen mit negativer Erziehung zusammenhängen oder ob verschiedene Erziehungsfaktoren bei den jeweiligen Störungsbildern eine störungstypische Rolle spielen. Methode: Einschlägige Studien aus dem Zeitraum von 1994 bis 2014 wurden systematisch analysiert. Neben generellen Zusammenhängen wurden moderierende Faktoren ermittelt. Ergebnisse: Während kindliche ADHS verstärkt mit elterlicher Negativität, zum Teil aber auch mit Kontrolle, assoziiert ist, zeigt sich bei kindlichen AS insbesondere ein Zusammenhang mit elterlicher Kontrolle. Die Ergebnisse werden von verschiedenen Faktoren wie Erhebungsmethode (Fragebogen vs. Beobachtung) und Medikation moderiert. Schlussfolgerungen: Störungstypische Zusammenhänge zwischen kindlicher Psychopathologie und Erziehungsfaktoren betonen die Relevanz gegenüberstellender Forschung von ADHS und AS und können Implikationen für eine störungsorientierte Psychotherapie haben.
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Affiliation(s)
- Julia Asbrand
- Abteilung für Klinische Psychologie und Psychotherapie, Institut für Psychologie, Albert-Ludwigs-Universität Freiburg
| | - Teresa Lerach
- Abteilung für Klinische Psychologie und Psychotherapie, Institut für Psychologie, Albert-Ludwigs-Universität Freiburg
| | - Brunna Tuschen-Caffier
- Abteilung für Klinische Psychologie und Psychotherapie, Institut für Psychologie, Albert-Ludwigs-Universität Freiburg
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8
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Rowan JD, McCarty MK, Kundey SMA, Osburn CD, Renaud SM, Kelley BM, Matoushek AW, Fountain SB. Adolescent exposure to methylphenidate impairs serial pattern learning in the serial multiple choice (SMC) task in adult rats. Neurotoxicol Teratol 2015. [PMID: 26225921 DOI: 10.1016/j.ntt.2015.07.007] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
The long-term effects of adolescent exposure to methylphenidate (MPD) on adult cognitive capacity are largely unknown. We utilized a serial multiple choice (SMC) task, which is a sequential learning paradigm for studying complex learning, to observe the effects of methylphenidate exposure during adolescence on later serial pattern acquisition during adulthood. Following 20.0mg/kg/day MPD or saline exposure for 5 days/week for 5 weeks during adolescence, male rats were trained to produce a highly structured serial response pattern in an octagonal operant chamber for water reinforcement as adults. During a transfer phase, a violation to the previously-learned pattern structure was introduced as the last element of the sequential pattern. Results indicated that while rats in both groups were able to learn the training and transfer patterns, adolescent exposure to MPD impaired learning for some aspects of pattern learning in the training phase which are learned using discrimination learning or serial position learning. In contrast adolescent exposure to MPD had no effect on other aspects of pattern learning which have been shown to tap into rule learning mechanisms. Additionally, adolescent MPD exposure impaired learning for the violation element in the transfer phase. This indicates a deficit in multi-item learning previously shown to be responsible for violation element learning. Thus, these results clearly show that adolescent MPD produced multiple cognitive impairments in male rats that persisted into adulthood long after MPD exposure ended.
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Affiliation(s)
- James D Rowan
- Department of Psychology, Wesleyan College, Macon, GA 31210-4462, USA.
| | - Madison K McCarty
- Department of Psychology, Wesleyan College, Macon, GA 31210-4462, USA.
| | | | - Crystal D Osburn
- Department of Psychology, Wesleyan College, Macon, GA 31210-4462, USA.
| | - Samantha M Renaud
- Department of Psychological Sciences, Kent State University, Kent, OH 44242-0001, USA.
| | - Brian M Kelley
- Department of Psychology, Bridgewater College, Bridgewater, VA 22812, USA.
| | | | - Stephen B Fountain
- Department of Psychological Sciences, Kent State University, Kent, OH 44242-0001, USA.
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9
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A pharmacokinetic model of oral methylphenidate in the rat and effects on behavior. Pharmacol Biochem Behav 2015; 131:143-53. [PMID: 25641666 DOI: 10.1016/j.pbb.2015.01.005] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/25/2014] [Revised: 12/31/2014] [Accepted: 01/09/2015] [Indexed: 11/20/2022]
Abstract
Most animal studies using methylphenidate (MP) do not administer it the same way it is administered clinically (orally), but rather by injection, resulting in an altered pharmacokinetic profile (quicker and higher peak concentrations). We evaluated several oral-dosing regimens in rats, including dual-dose drinking, to mimic clinical drug delivery. Using an 8-hour-limited-access-drinking-paradigm, MP solutions were delivered at different doses (20, 30, or 60mg/kg/day; as well as dual-dosages of 4 and 10mg/kg/day, 20 and 30mg/kg/day, or 30 and 60mg/kg/day, in which the low dose was administered in the first hour of drinking followed by 7 h of drinking the high dose). Plasma was assayed for MP levels at many time points. Results showed that an 8-hour limited drinking of a dual-dosage 30/60mg/kg MP solution achieved a pharmacokinetic profile similar to clinically administered doses of MP at the high end of the spectrum (peaking at ~30ng/mL), while the 4/10mg/kg MP dual-dosage produced plasma levels in the range produced by typically prescribed clinical doses of MP (peaking at ~8ng/mL). Treatment with the higher dual-dosage (HD: 30/60mg/kg) resulted in hyperactivity, while the lower (LD: 4/10mg/kg) had no effect. Chronic effects of these dual-dosages were assessed throughout three months of treatment and one month of abstinence, beginning in adolescence. MP dose-dependently decreased body weight, which remained attenuated throughout abstinence. MP decreased food intake during early treatment, suggesting that MP may be an appetite suppressant and may also speed metabolism and/or suppress growth. Chronic HD MP resulted in hyperactivity limited during the dark cycle, decreased exploratory behavior, and increased anxiolytic behavior. Findings suggest that these dual-dosage-drinking-paradigms can be used to examine the effects of clinically relevant pharmacokinetic doses of MP and that chronic treatment with such dosages can result in long-lasting developmental and behavioral changes.
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10
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Krall DM, Lim SL, Cooper AM, Burleson PW, Rhoades DJ, Jacquemin SJ, Willmore DC, Spears FM, Willmore CB. Withdrawal effect of chronic amphetamine exposure during adolescence on complex maze performance. Addict Biol 2014; 19:634-42. [PMID: 23374198 DOI: 10.1111/adb.12029] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
National survey data suggest a steady increase in the diagnosis and treatment of mental disorders in children, particularly Attention Deficit/Hyperactivity Disorder (ADHD). As nearly all children diagnosed with ADHD are prescribed stimulant drugs, rationale exists to quantitatively characterize behavioral responses following withdrawal from chronic stimulant dosing. These rodent experiments involved chronic administration of 7.5 mg/kg, s.c. amphetamine to subjects throughout adolescence followed by cognitive tests to gauge learning and performance during the withdrawal stage 7 to 14 days past withdrawal. Tests used a complex Stone 14-unit multiple T-maze, which is a robust paradigm for demonstrating age-related differences in rodent models when behavioral cognitive endpoints are used. Results reveal that amphetamine-treated subjects committed fewer major and retracing errors with increased minor errors and a significantly lower mean completion time. These findings suggest that pharmacotherapy aimed at adolescent-phase treatment of ADHD does not provoke spatial memory deficits at times proximal to drug withdrawal and lends support to amphetamine use in the treatment of ADHD children.
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Affiliation(s)
- Daniel M. Krall
- Department of Pharmaceutical Sciences; Ohio Northern University; Ada OH USA
- College of Medicine; University of Cincinnati; Cincinnati OH USA
| | - Stephanie L. Lim
- Department of Pharmaceutical Sciences; Harding University; Searcy AR USA
- Harvard University; Boston MA USA
| | - Abby M. Cooper
- Department of Pharmaceutical Sciences; Ohio Northern University; Ada OH USA
| | - Paul W. Burleson
- Department of Pharmaceutical Sciences; Ohio Northern University; Ada OH USA
| | - Derek J. Rhoades
- Department of Pharmaceutical Sciences; Ohio Northern University; Ada OH USA
- Chemistry Department; University of California; San Diego CA USA
| | - Stephen J. Jacquemin
- Department of Pharmaceutical Sciences; Ohio Northern University; Ada OH USA
- Department of Biology; Ball State University; Muncie IN USA
| | - Daryl C. Willmore
- Department of Pharmaceutical Sciences; Ohio Northern University; Ada OH USA
| | - F. Martin Spears
- Department of Pharmaceutical Sciences; Harding University; Searcy AR USA
| | - Catherine B. Willmore
- Department of Pharmaceutical Sciences; Ohio Northern University; Ada OH USA
- Department of Pharmaceutical Sciences; Harding University; Searcy AR USA
- Department of Pharmaceutical Science; Union University; Jackson TN USA
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The effects of Psychotropic drugs On Developing brain (ePOD) study: methods and design. BMC Psychiatry 2014; 14:48. [PMID: 24552282 PMCID: PMC3930821 DOI: 10.1186/1471-244x-14-48] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/13/2013] [Accepted: 01/31/2014] [Indexed: 01/16/2023] Open
Abstract
BACKGROUND Animal studies have shown that methylphenidate (MPH) and fluoxetine (FLX) have different effects on dopaminergic and serotonergic system in the developing brain compared to the developed brain. The effects of Psychotropic drugs On the Developing brain (ePOD) study is a combination of different approaches to determine whether there are related findings in humans. METHODS/DESIGN Animal studies were carried out to investigate age-related effects of psychotropic drugs and to validate new neuroimaging techniques. In addition, we set up two double-blind placebo controlled clinical trials with MPH in 50 boys (10-12 years) and 50 young men (23-40 years) suffering from ADHD (ePOD-MPH) and with FLX in 40 girls (12-14 years) and 40 young women (23-40 years) suffering from depression and anxiety disorders (ePOD-SSRI). Trial registration numbers are: Nederlands Trial Register NTR3103 and NTR2111. A cross-sectional cohort study on age-related effects of these psychotropic medications in patients who have been treated previously with MPH or FLX (ePOD-Pharmo) is also ongoing. The effects of psychotropic drugs on the developing brain are studied using neuroimaging techniques together with neuropsychological and psychiatric assessments of cognition, behavior and emotion. All assessments take place before, during (only in case of MPH) and after chronic treatment. DISCUSSION The combined results of these approaches will provide new insight into the modulating effect of MPH and FLX on brain development.
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Acute dose-related differential effects of methylphenidate on murine cystometric parameters. Int Neurourol J 2014; 17:162-7. [PMID: 24466462 PMCID: PMC3895507 DOI: 10.5213/inj.2013.17.4.162] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2013] [Accepted: 11/23/2013] [Indexed: 01/23/2023] Open
Abstract
Purpose Methylphenidate is the most widely used central nervous system stimulant in patients with attention deficit hyperactivity disorder. However, few studies have assessed its effects on voiding. Various doses of methylphenidate were investigated for their effects on cystometric parameters in conscious mice. Methods Ten male C57BL/6 mice, weighing between 20 and 23 g, were used in this study. To compare the acute drug responses before and after the oral medication was administered in the awake condition, we injected the solution through a catheter inserted into the stomach. Methylphenidate (1.25, 2.5, and 5 mg/kg) in an injection volume of 0.05 mL was administered. Results Four mice that received high doses of methylphenidate (2.5 and 5 mg/kg) showed no voiding contraction, with urine leakage. Six mice that received a low dose of methylphenidate (1.25 mg/kg) showed typical micturition cycles before and after administration. The micturition pressure decreased and bladder capacity increased without an increased residual volume after administration. Conclusions Methylphenidate has differential, dose-dependent effects on the function of the lower urinary tract, due to the dependent relationship between the brain and lower urinary tract. Especially at higher doses, this drug may interfere with normal micturition. Therefore, more detailed clinical or experimental studies are warranted in the future.
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What influences clinicians' decisions about ADHD medication? Initial data from the Influences on Prescribing for ADHD Questionnaire (IPAQ). Eur Child Adolesc Psychiatry 2013; 22:533-42. [PMID: 23455602 DOI: 10.1007/s00787-013-0393-y] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/20/2012] [Accepted: 02/11/2013] [Indexed: 12/13/2022]
Abstract
Despite evidence for its efficacy and effectiveness, the use of medication for the treatment of ADHD remains controversial. Little is known about the factors that influence clinicians' decisions to use medication for ADHD. Here, we present initial data on the attitudes of prescribing clinicians from the Influences on Prescribing for ADHD Questionnaire (IPAQ)-a new clinician-completed, 40-item scale. The eight IPAQ subscales cover attitudes towards (1) treatment outcome optimisation, (2) the use of rule based over more informal approaches, (3) side effects, (4) symptoms control as the primary goal of treatment, (5) the influence of external pressure on medication-related decisions, (6) the value of taking the child's views into account, (7) long-term medication use and (8) the value of psychosocial approaches for the treatment of ADHD. Sixty-eight clinicians from Belgium and the UK took part. All subscales had acceptable levels of internal reliability (Chronbach's alpha = 0.62-0.78). Overall, clinicians reported taking a rule-based approach to prescribing with a focus on treatment optimisation, taking the child's view into account and valuing psycho-social approaches. They focused on treating broader patterns of impairment, but were wary of the potential side effects and long-term treatment. Psychiatrists scored high on their focus on symptom control and preference for long-term medication use, while paediatricians reported using more rule-based approaches. We identified four distinctive response profiles: (1) pro-psychosocial; (2) medication focused; (3) unsystematic; and (4) response optimizers. Future larger scale studies are required to replicate these profiles and to explore their relationship with prescribing behaviour and treatment outcomes.
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Spencer TJ, Brown A, Seidman LJ, Valera EM, Makris N, Lomedico A, Faraone SV, Biederman J. Effect of psychostimulants on brain structure and function in ADHD: a qualitative literature review of magnetic resonance imaging-based neuroimaging studies. J Clin Psychiatry 2013; 74:902-17. [PMID: 24107764 PMCID: PMC3801446 DOI: 10.4088/jcp.12r08287] [Citation(s) in RCA: 102] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/15/2012] [Accepted: 04/19/2013] [Indexed: 10/26/2022]
Abstract
OBJECTIVE To evaluate the impact of therapeutic oral doses of stimulants on the brains of ADHD subjects as measured by magnetic resonance imaging (MRI)-based neuroimaging studies (morphometric, functional, spectroscopy). DATA SOURCES We searched PubMed and ScienceDirect through the end of calendar year 2011 using the keywords (1) psychostimulants or methylphenidate or amphetamine, and (2) neuroimaging or MRI or fMRI, and (3) ADHD or ADD or attention-deficit/hyperactivity disorder or attention deficit hyperactivity disorder. STUDY SELECTION We included only English language articles with new data from case-control or placebo controlled studies that examined attention-deficit/hyperactivity disorder (ADHD) subjects on and off psychostimulants (as well as 5 relevant review articles). DATA EXTRACTION We combined details of study design and medication effects in each imaging modality. RESULTS We found 29 published studies that met our criteria. These included 6 structural MRI, 20 functional MRI studies, and 3 spectroscopy studies. Methods varied widely in terms of design, analytic technique, and regions of the brain investigated. Despite heterogeneity in methods, however, results were consistent. With only a few exceptions, the data on the effect of therapeutic oral doses of stimulant medication suggest attenuation of structural and functional alterations found in unmedicated ADHD subjects relative to findings in controls. CONCLUSIONS Despite the inherent limitations and heterogeneity of the extant MRI literature, our review suggests that therapeutic oral doses of stimulants decrease alterations in brain structure and function in subjects with ADHD relative to unmedicated subjects and controls. These medication-associated brain effects parallel, and may underlie, the well-established clinical benefits.
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Affiliation(s)
- Thomas J. Spencer
- Massachusetts General Hospital, Clinical and Research Program in Pediatric Psychopharmacology, Boston, MA 02114,Harvard Medical School Department of Psychiatry, Massachusetts General Hospital, Boston, MA 02129,Massachusetts General Hospital, Neuroimaging Program, Clinical and Research Programs in Pediatric Psychopharmacology and Adult ADHD, Boston, MA 02114
| | - Ariel Brown
- Massachusetts General Hospital, Clinical and Research Program in Pediatric Psychopharmacology, Boston, MA 02114,Massachusetts General Hospital, Neuroimaging Program, Clinical and Research Programs in Pediatric Psychopharmacology and Adult ADHD, Boston, MA 02114
| | - Larry J. Seidman
- Massachusetts General Hospital, Clinical and Research Program in Pediatric Psychopharmacology, Boston, MA 02114,Harvard Medical School Department of Psychiatry, Massachusetts General Hospital, Boston, MA 02129,Massachusetts General Hospital, Neuroimaging Program, Clinical and Research Programs in Pediatric Psychopharmacology and Adult ADHD, Boston, MA 02114,Harvard Medical School Departments of Neurology and Radiology Services, Center for Morphometric Analysis, Massachusetts General Hospital, Boston, MA 02129,MGH/HST Athinoula A. Martinos Center for Biomedical Imaging, Charlestown, MA 02129,Harvard Medical School, Department of Psychiatry, Massachusetts Mental Health Center Public Psychiatry Division, Beth Israel Deaconess Medical Center, Boston, MA 02115
| | - Eve M. Valera
- Massachusetts General Hospital, Clinical and Research Program in Pediatric Psychopharmacology, Boston, MA 02114,Harvard Medical School Department of Psychiatry, Massachusetts General Hospital, Boston, MA 02129,Massachusetts General Hospital, Neuroimaging Program, Clinical and Research Programs in Pediatric Psychopharmacology and Adult ADHD, Boston, MA 02114,MGH/HST Athinoula A. Martinos Center for Biomedical Imaging, Charlestown, MA 02129
| | - Nikos Makris
- Harvard Medical School Department of Psychiatry, Massachusetts General Hospital, Boston, MA 02129,Massachusetts General Hospital, Neuroimaging Program, Clinical and Research Programs in Pediatric Psychopharmacology and Adult ADHD, Boston, MA 02114,Harvard Medical School Departments of Neurology and Radiology Services, Center for Morphometric Analysis, Massachusetts General Hospital, Boston, MA 02129,MGH/HST Athinoula A. Martinos Center for Biomedical Imaging, Charlestown, MA 02129
| | - Alexandra Lomedico
- Massachusetts General Hospital, Clinical and Research Program in Pediatric Psychopharmacology, Boston, MA 02114
| | - Stephen V. Faraone
- Departments of Psychiatry and of Neuroscience and Physiology, SUNY Upstate Medical University, Syracuse, NY, 13210
| | - Joseph Biederman
- Massachusetts General Hospital, Clinical and Research Program in Pediatric Psychopharmacology, Boston, MA 02114,Harvard Medical School Department of Psychiatry, Massachusetts General Hospital, Boston, MA 02129,Massachusetts General Hospital, Neuroimaging Program, Clinical and Research Programs in Pediatric Psychopharmacology and Adult ADHD, Boston, MA 02114
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Chacko A, Uderman J, Feirsen N, Bedard AC, Marks D. Learning and cognitive disorders: multidiscipline treatment approaches. Child Adolesc Psychiatr Clin N Am 2013; 22:457-77, vi. [PMID: 23806314 PMCID: PMC4539272 DOI: 10.1016/j.chc.2013.03.006] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
This article provides a select review of treatments for addressing reading disorder, mathematics disorder, disorder of written expression, auditory processing disorder, and poor working memory. This information will be valuable to practitioners in determining the suitability of certain treatments for these various disorders and problems, which has direct implications for providing comprehensive, multidisciplinary treatment for youth.
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Affiliation(s)
- Anil Chacko
- Department of Psychology, Queens College, City University of New York (CUNY)
- Department of Psychology, The Graduate School and University Center, CUNY
- Department of Psychiatry, The Mount Sinai School of Medicine
- Department of Child and Adolescent Psychiatry, New York University School of Medicine
| | - Jodi Uderman
- Department of Psychology, Queens College, City University of New York (CUNY)
- Department of Psychology, The Graduate School and University Center, CUNY
| | - Nicole Feirsen
- Department of Psychology, Queens College, City University of New York (CUNY)
- Department of Psychology, The Graduate School and University Center, CUNY
| | | | - David Marks
- Department of Child and Adolescent Psychiatry, New York University School of Medicine
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Abuse and dependence liability analysis of methylphenidate in the spontaneously hypertensive rat model of attention-deficit/hyperactivity disorder (ADHD): what have we learned? Arch Pharm Res 2013; 36:400-10. [PMID: 23471559 DOI: 10.1007/s12272-013-0037-2] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2012] [Accepted: 02/05/2013] [Indexed: 01/08/2023]
Abstract
Methylphenidate is the most prescribed stimulant medication for attention-deficit/hyperactivity disorder (ADHD). Despite the well documented clinical benefits of the drug, several questions remain unanswered concerning the effects of extended methylphenidate use (e.g. can methylphenidate be abused by ADHD patients? does repeated methylphenidate treatment produce addiction?). Preclinical studies can help address the long-term safety of clinical treatments, moreover animal studies provide valuable information on the details of drug actions. The spontaneously hypertensive rat (SHR), bred from normotensive Wistar Kyoto rat strain, is considered as the best validated and the most widely used animal model of ADHD. We reviewed the findings of research reports that investigated the abuse and dependence liability of methylphenidate in SHR. In particular, we surveyed the studies which investigated the effects of methylphenidate pretreatment on subsequent methylphenidate-induced conditioned place preference or self-administration for they may give insights into the abuse or dependence liability of long-term methylphenidate treatment in ADHD.
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Urban KR, Li YC, Gao WJ. Treatment with a clinically-relevant dose of methylphenidate alters NMDA receptor composition and synaptic plasticity in the juvenile rat prefrontal cortex. Neurobiol Learn Mem 2013; 101:65-74. [PMID: 23333502 DOI: 10.1016/j.nlm.2013.01.004] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2012] [Revised: 01/04/2013] [Accepted: 01/08/2013] [Indexed: 11/27/2022]
Abstract
Methylphenidate (Ritalin, MPH) is the most commonly prescribed psychoactive drug for children. Used to treat attention-deficit/hyperactivity disorder (ADHD) and for cognitive enhancement in healthy individuals, its cellular mechanisms of action and potential long-term effects are poorly understood. We recently reported that a clinically relevant (1 mg/kg i.p., single injection) dose of MPH significantly decreased neuronal excitability in the juvenile rat prefrontal cortical neurons. Here we further explore the actions of acute treatment with MPH on the level of NMDA receptor subunits and NMDA receptor-mediated short- and long-term synaptic plasticity in the juvenile rat prefrontal cortical neurons. We found that a single dose of MPH treatment (1 mg/kg, intraperitoneal) significantly decreased the surface and total protein levels of NMDA receptor subunits NR1 and NR2B, but not NR2A, in the juvenile prefrontal cortex. In addition, the amplitude, decay time and charge transfer of NMDA receptor-mediated EPSCs were significantly decreased whereas the amplitude and short-term depression of AMPA receptor-mediated EPSCs were significantly increased in the prefrontal neurons. Furthermore, MPH treatment also significantly increased the probability and magnitude of LTP induction, but had only a small effect on LTD induction in juvenile rat prefrontal cortical neurons. Our data thus present a novel mechanism of action of MPH, i.e., changes in glutamatergic receptor-mediated synaptic plasticity following early-life treatment. Furthermore, since a single dosage resulted in significant changes in NMDA receptors, off-label usage by healthy individuals, especially children and adolescents, may result in altered potential for plastic learning.
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Affiliation(s)
- Kimberly R Urban
- Department of Neurobiology and Anatomy, Drexel University College of Medicine, Philadelphia, PA 19129, USA
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Urban KR, Waterhouse BD, Gao WJ. Distinct age-dependent effects of methylphenidate on developing and adult prefrontal neurons. Biol Psychiatry 2012; 72:880-8. [PMID: 22609367 PMCID: PMC3433628 DOI: 10.1016/j.biopsych.2012.04.018] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/02/2011] [Revised: 04/17/2012] [Accepted: 04/18/2012] [Indexed: 01/16/2023]
Abstract
BACKGROUND Methylphenidate (MPH) has long been used to treat attention-deficit/hyperactivity disorder (ADHD); however, its cellular mechanisms of action and potential effects on prefrontal cortical circuitry are not well understood, particularly in the developing brain system. A clinically relevant dose range for rodents has been established in the adult animal; however, how this range will translate to juvenile animals has not been established. METHODS Juvenile (postnatal day [PD] 15) and adult (PD90) Sprague Dawley rats were treated with MPH or saline. Whole-cell patch clamp recording was used to examine the neuronal excitability and synaptic transmission in pyramidal neurons of prefrontal cortex. Recovery from MPH treatment was also examined at 1, 5, and 10 weeks following drug cessation. RESULTS A dose of 1 mg/kg intraperitoneal MPH, either single dose or chronic treatment (well within the accepted therapeutic range for adults), produced significant depressive effects on pyramidal neurons by increasing hyperpolarization-activated currents in juvenile rat prefrontal cortex, while exerting excitatory effects in adult rats. Minimum clinically-relevant doses (.03 to .3 mg/kg) also produced depressive effects in juvenile rats, in a linear dose-dependent manner. Function recovered within 1 week from chronic 1 mg/kg treatment, chronic treatment with 3 and 9 mg/kg resulted in depression of prefrontal neurons lasting 10 weeks and beyond. CONCLUSIONS These results suggest that the juvenile prefrontal cortex is supersensitive to methylphenidate, and the accepted therapeutic range for adults is an overshoot. Juvenile treatment with MPH may result in long-lasting, potentially permanent, changes to excitatory neuron function in the prefrontal cortex of juvenile rats.
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Affiliation(s)
| | | | - Wen-Jun Gao
- Correspondence: Wen-Jun Gao, M.D., Ph.D., Department of Neurobiology and Anatomy, Drexel University College of Medicine, 2900 Queen Lane, Philadelphia, PA 19129, Phone: (215) 991-8907, Fax: (215) 843-9802,
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Gilsbach S, Günther T, Konrad K. Was wissen wir über Langzeiteffekte von Methylphenidatbehandlung auf die Hirnentwicklung von Kindern und Jugendlichen mit einer Aufmerksamkeitsdefizit-/Hyperaktivitätsstörung (ADHS)? ZEITSCHRIFT FUR NEUROPSYCHOLOGIE 2011. [DOI: 10.1024/1016-264x/a000040] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Obwohl Psychostimulanzien zu den Behandlungsmethoden der ersten Wahl bei Kindern mit einer Aufmerksamkeitsdefizit/-Hyperaktivitätsstörung (ADHS) im Kindes- und Jugendalter gehören, sind mögliche Langzeitfolgen einer Stimulanzientherapie noch nicht ausreichend erforscht. Während eine kurzzeitige positive Wirkung von Stimulanzien auf Aufmerksamkeitsleistungen als gesichert gilt, sind die langfristigen Auswirkungen insbesondere einer Medikation in der frühen Kindheit sowie einer Dauermedikation noch weitestgehend unbekannt. Verschiedene Studien ergaben Hinweise auf einen Einfluss einer Dauermedikation mit Stimulanzien sowohl auf die strukturelle als auch auf funktionelle Hirnentwicklung. Des Weiteren sollten mögliche unerwünschte kognitive und motivationale Nebenwirkungen einer Medikation mit Methylphenidat genauer in Betracht gezogen werden. Insgesamt zeigt sich die Datenlage heterogen und es mangelt an Studien mit ausreichend großen Fallzahlen.
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Affiliation(s)
- Susanne Gilsbach
- Klinik für Psychiatrie, Psychotherapie und Psychosomatik des Kindes- und Jugendalters
| | - Thomas Günther
- Lehr- und Forschungsgebiet Klinische Neuropsychologie des Kindes- und Jugendalters, RWTH-Aachen
| | - Kerstin Konrad
- Lehr- und Forschungsgebiet Klinische Neuropsychologie des Kindes- und Jugendalters, RWTH-Aachen
- JARA-Brain Translational Medicine
- Cognitive Development, Institute of Neuroscience and Medicine (INM-III), Research Center Juelich
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Sagvolden T. Impulsiveness, overactivity, and poorer sustained attention improve by chronic treatment with low doses of l-amphetamine in an animal model of Attention-Deficit/Hyperactivity Disorder (ADHD). Behav Brain Funct 2011; 7:6. [PMID: 21450079 PMCID: PMC3086861 DOI: 10.1186/1744-9081-7-6] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2008] [Accepted: 03/30/2011] [Indexed: 11/17/2022] Open
Abstract
Background ADHD is currently defined as a cognitive/behavioral developmental disorder where all clinical criteria are behavioral. Overactivity, impulsiveness, and inattentiveness are presently regarded as the main clinical symptoms. There is no biological marker, but there is considerable evidence to suggest that ADHD behavior is associated with poor dopaminergic and noradrenergic modulation of neuronal circuits that involve the frontal lobes. The best validated animal model of ADHD, the Spontaneously Hypertensive Rat (SHR), shows pronounced overactivity, impulsiveness, and deficient sustained attention. The primary objective of the present research was to investigate behavioral effects of a range of doses of chronic l-amphetamine on ADHD-like symptoms in the SHR. Methods The present study tested the behavioral effects of 0.75 and 2.2 mg l-amphetamine base/kg i.p. in male SHRs and their controls, the Wistar Kyoto rat (WKY). ADHD-like behavior was tested with a visual discrimination task measuring overactivity, impulsiveness and inattentiveness. Results The striking impulsiveness, overactivity, and poorer sustained attention seen during baseline conditions in the SHR were improved by chronic treatment with l-amphetamine. The dose-response curves were, however, different for the different behaviors. Most significantly, the 0.75 mg/kg dose of l-amphetamine improved sustained attention without reducing overactivity and impulsiveness. The 2.2 mg/kg dose improved sustained attention as well as reduced SHR overactivity and impulsiveness. Discussion The effects of l-amphetamine to reduce the behavioral symptoms of ADHD in the SHR were maintained over the 14 days of daily dosing with no evidence of tolerance developing.
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Affiliation(s)
- Terje Sagvolden
- Institute of Basic Medical Sciences, Department of Physiology, University of Oslo, Blindern, NO-0317 Oslo, Norway.
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Pires VA, Pamplona FA, Pandolfo P, Prediger RD, Takahashi RN. Chronic caffeine treatment during prepubertal period confers long-term cognitive benefits in adult spontaneously hypertensive rats (SHR), an animal model of attention deficit hyperactivity disorder (ADHD). Behav Brain Res 2010; 215:39-44. [DOI: 10.1016/j.bbr.2010.06.022] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2010] [Revised: 06/10/2010] [Accepted: 06/16/2010] [Indexed: 02/03/2023]
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Yang PB, Cuellar DO, Swann AC, Dafny N. Age and genetic strain differences in response to chronic methylphenidate administration. Behav Brain Res 2010; 218:206-17. [PMID: 21111006 DOI: 10.1016/j.bbr.2010.11.034] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2010] [Revised: 11/11/2010] [Accepted: 11/16/2010] [Indexed: 02/05/2023]
Abstract
Methylphenidate hydrochloride (MPD) is a psychostimulant used in the treatment of attention deficit hyperactive disorder (ADHD) in adolescents and adults alike. Adolescence involves a period of neural development that is highly susceptible to environmental and pharmacological influence. Exposure to a psychostimulant like MPD during this crucial time period may cause permanent changes in neuronal function and formation. Another factor that may influence changes in neuronal function and formation is genetic variability. It has been reported that genetic variability affects both the initial behavioral response to drugs in general and psychostimulants in particular, and subsequently whether tolerance or sensitization is induced. The objective of the present study is to investigate the dose-response effects of repeated MPD administration (0.6, 2.5, or 10.0mg/kg, i.p.) using an open field assay to investigate if there are differences between adolescent and adult Wistar-Kyoto (WKY), Spontaneously Hyperactive rat (SHR), and Sprague-Dawley (SD) rats, respectively, and if the genetic variability between the strains influences the degree of change in locomotion. The acute and chronic administration of MPD resulted in unique differences in the level of increasing intensity in locomotor activity in each rat strain, with adult rats for the most part having a more intense increase in locomotor activity when compared to their adolescent counterparts. In conclusion, significant response differences among rat strains and age to acute and chronic MPD administration were observed only following the 2.5 and 10.0mg/kg i.p. doses and not following the lower MPD dose (0.6 mg//kg i.p.). In addition the variability in activity among the rat strain and age suggests that MPD may affect the same neuronal circuit differently in each strain and age. The unique differences among the individual locomotor indices suggest also that each locomotor index is regulated by different neuronal circuits, and each affected differently by MPD.
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Affiliation(s)
- Pamela B Yang
- Department of Anatomy and Neurobiology, University of California, Irvine, School of Medicine, Irvine, CA 92697, USA
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Perinatal asphyxia: current status and approaches towards neuroprotective strategies, with focus on sentinel proteins. Neurotox Res 2010; 19:603-27. [PMID: 20645042 PMCID: PMC3291837 DOI: 10.1007/s12640-010-9208-9] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2010] [Revised: 04/19/2010] [Accepted: 06/30/2010] [Indexed: 12/19/2022]
Abstract
Delivery is a stressful and risky event menacing the newborn. The mother-dependent respiration has to be replaced by autonomous pulmonary breathing immediately after delivery. If delayed, it may lead to deficient oxygen supply compromising survival and development of the central nervous system. Lack of oxygen availability gives rise to depletion of NAD+ tissue stores, decrease of ATP formation, weakening of the electron transport pump and anaerobic metabolism and acidosis, leading necessarily to death if oxygenation is not promptly re-established. Re-oxygenation triggers a cascade of compensatory biochemical events to restore function, which may be accompanied by improper homeostasis and oxidative stress. Consequences may be incomplete recovery, or excess reactions that worsen the biological outcome by disturbed metabolism and/or imbalance produced by over-expression of alternative metabolic pathways. Perinatal asphyxia has been associated with severe neurological and psychiatric sequelae with delayed clinical onset. No specific treatments have yet been established. In the clinical setting, after resuscitation of an infant with birth asphyxia, the emphasis is on supportive therapy. Several interventions have been proposed to attenuate secondary neuronal injuries elicited by asphyxia, including hypothermia. Although promising, the clinical efficacy of hypothermia has not been fully demonstrated. It is evident that new approaches are warranted. The purpose of this review is to discuss the concept of sentinel proteins as targets for neuroprotection. Several sentinel proteins have been described to protect the integrity of the genome (e.g. PARP-1; XRCC1; DNA ligase IIIα; DNA polymerase β, ERCC2, DNA-dependent protein kinases). They act by eliciting metabolic cascades leading to (i) activation of cell survival and neurotrophic pathways; (ii) early and delayed programmed cell death, and (iii) promotion of cell proliferation, differentiation, neuritogenesis and synaptogenesis. It is proposed that sentinel proteins can be used as markers for characterising long-term effects of perinatal asphyxia, and as targets for novel therapeutic development and innovative strategies for neonatal care.
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Paul-Jordanov I, Bechtold M, Gawrilow C. Methylphenidate and if-then plans are comparable in modulating the P300 and increasing response inhibition in children with ADHD. ACTA ACUST UNITED AC 2010; 2:115-26. [DOI: 10.1007/s12402-010-0028-9] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2009] [Accepted: 05/19/2010] [Indexed: 11/30/2022]
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Sonuga-Barke EJS, Halperin JM. Developmental phenotypes and causal pathways in attention deficit/hyperactivity disorder: potential targets for early intervention? J Child Psychol Psychiatry 2010; 51:368-89. [PMID: 20015192 DOI: 10.1111/j.1469-7610.2009.02195.x] [Citation(s) in RCA: 233] [Impact Index Per Article: 16.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Early intervention approaches have rarely been implemented for the prevention of attention deficit/hyperactivity disorder (ADHD). In this paper we explore whether such an approach may represent an important new direction for therapeutic innovation. We propose that such an approach is most likely to be of value when grounded in and informed by developmental models of the dynamic, complex and heterogeneous nature of the condition. First, we set out a rationale for early intervention grounded in the science of ADHD viewed through developmental models. Second, we re-examine the concept of disorder-onset from the perspective of developmental trajectories and phenotypes. Third, we examine potential causal pathways to ADHD with regard to originating risk, pathophysiological mediators, environmental moderators and developmental continuities. Finally, we explore the potential value of strategies for identifying young children at risk for ADHD, and implementing interventions in ways that can target these underlying pathogenic processes. The utility of such an approach represents an important area for future research but still requires 'proof of concept'. Therefore prior to widespread clinical implementation, far greater knowledge is required of (i) developmental pathways into ADHD, (ii) the value of identifying neuropsychological mediators of these pathways, and (iii) the extent to which targeting mediating mechanisms will improve treatment outcomes for children with ADHD.
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Affiliation(s)
- Edmund J S Sonuga-Barke
- Developmental Brain-Behaviour Laboratory, University of Southampton, Southampton, SO17 1BJ, UK
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Roessner V, Sagvolden T, Dasbanerjee T, Middleton FA, Faraone SV, Walaas SI, Becker A, Rothenberger A, Bock N. Methylphenidate normalizes elevated dopamine transporter densities in an animal model of the attention-deficit/hyperactivity disorder combined type, but not to the same extent in one of the attention-deficit/hyperactivity disorder inattentive type. Neuroscience 2010; 167:1183-91. [PMID: 20211696 DOI: 10.1016/j.neuroscience.2010.02.073] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2009] [Revised: 02/25/2010] [Accepted: 02/28/2010] [Indexed: 01/19/2023]
Abstract
The spontaneously hypertensive rat (SHR/NCrl) is a validated model of attention-deficit/hyperactivity disorder (ADHD) combined subtype, whereas a recently identified substrain of the Wistar Kyoto rat (WKY/NCrl) is a model of ADHD inattentive subtype. In this study, we first examined the expression of genes involved in dopamine signaling and metabolism in the dorsal striatum and ventral mesencephalon of these two rat strains, as well as three reference control strains (WKY/NHsd, WK/HanTac, and SD/NTac) using quantitative real time RT-PCR. Next, striatal dopamine transporter (DAT) density was determined by ligand binding assay in the two ADHD-like strains at different developmental stages and after methylphenidate treatment. In adult rats, the mRNA expression of DAT and tyrosine hydroxylase was elevated in SHR/NCrl and WKY/NCrl rats compared to control strains, with differences between SHR/NCrl and WKY/NCrl rats also evident. During normal development, changes of striatal DAT densities occurred in both strains with lower densities in WKY/NCrl compared to SHR/NCrl after day 25. Two-weeks methylphenidate treatment during different developmental stages was associated with decreased striatal DAT density in both rat strains compared to the non-treated rats with more pronounced effects followed prepubertal treatment. These results suggest differences in the pathophysiology of the combined versus the predominantly inattentive animal model of ADHD. Finally, treatment with methylphenidate might reduce elevated DAT levels more effectively in the combined subtype especially when applied before puberty.
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Affiliation(s)
- V Roessner
- Department of Child and Adolescent Psychiatry, University of Goettingen, Germany
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Roessner V, Manzke T, Becker A, Rothenberger A, Bock N. Development of 5-HT transporter density and long-term effects of methylphenidate in an animal model of ADHD. World J Biol Psychiatry 2010; 10:581-5. [PMID: 19172439 DOI: 10.1080/15622970802653709] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
Although stimulants as the treatment of choice are widely prescribed in ADHD, little is known about their long-term neurobiological effects. Hence, for the first time the present study examined the long-term effects of chronic methylphenidate (MPH) administration on striatal 5-hydroxytryptamine transporter (5-HTT) densities in an animal model of ADHD. First, it compared the normal development of striatal 5-HTT densities of spontaneously hypertensive rats (SHR) as an animal model of ADHD and Wistar Kyoto (WKY) rats as controls; binding of the highly selective ligand of 5-HTT [(3)H]paroxetine was determined on membrane preparations of the striatum of SHR and WKY rats on postnatal days 25, 50, and 90, i.e. from the time of weaning until adulthood. Second, the long-term effect of chronic administration of 2 mg/kg per day MPH at two different developmental stages (days 25-39 or 50-64) on the striatal 5-HTT density was examined in both rat strains at day 90. Long-term effects of MPH treatment on striatal 5-HTT density in adulthood could be ruled out in both healthy (WKY) and "ADHD" rats (SHR). But a higher striatal 5-HTT density in older SHR versus WKY rats might indicate ADHD specific changes in the 5-HT system that needs further investigation not only in animals.
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Affiliation(s)
- Veit Roessner
- Department of Child and Adolescent Psychiatry, University of Goettingen, Goettingen, Germany
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Luman M, Tripp G, Scheres A. Identifying the neurobiology of altered reinforcement sensitivity in ADHD: a review and research agenda. Neurosci Biobehav Rev 2009; 34:744-54. [PMID: 19944715 DOI: 10.1016/j.neubiorev.2009.11.021] [Citation(s) in RCA: 212] [Impact Index Per Article: 14.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2009] [Revised: 11/20/2009] [Accepted: 11/21/2009] [Indexed: 10/20/2022]
Abstract
ADHD is associated with altered reinforcement sensitivity, despite a number of inconsistent findings. This review focuses on the overlap and differences between seven neurobiologically valid models and lists 15 predictions assessing reinforcement sensitivity in ADHD. When comparing the models it becomes clear that there are great differences in the level of explanation. For example, some models try to explain a single core deficit in terms lower-level reinforcement systems, such as the dopamine transfer to reward back in time. Other models explain multiple deficits, by describing higher-level systems, such as impaired bottom-up prefrontal activation. When reviewing the available experimental evidence in support of the predictions, most experimental studies have been focusing on behavioral changes in the face of reward and response cost over no-reward, and on delay discounting. There is currently a lack in studies that focus on explaining underlying cognitive or neural mechanisms of altered reinforcement sensitivity in ADHD. Additionally, there is a lack in studies that try to understand what subgroup of children with ADHD shows alterations in reinforcement sensitivity. The scarcity in studies testing the neurobiological predictions is explained partly by a lack in knowledge how to test some of these predictions in humans. Nevertheless, we believe that these predictions can serve as a useful guide to the systematic evaluation of altered reinforcement sensitivity in ADHD.
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Affiliation(s)
- Marjolein Luman
- Department of Clinical Neurpsychology, Vrije Universiteit Amsterdam, Van der Boechorststraat 1, 1081 BT Amsterdam, The Netherlands.
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Wanchoo SJ, Lee MJ, Swann AC, Dafny N. Bilateral six-hydroxydopamine administration to PFC prevents the expression of behavioral sensitization to methylphenidate. Brain Res 2009; 1312:89-100. [PMID: 19932692 DOI: 10.1016/j.brainres.2009.11.035] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2009] [Revised: 11/09/2009] [Accepted: 11/17/2009] [Indexed: 11/28/2022]
Abstract
Psychostimulants like amphetamine and methylphenidate (MPD) are used to treat attention deficit hyperactivity disorder (ADHD), which is marked by developmentally inappropriate inattention, hyperactivity, and impulsivity. Neuropsychological analyses indicate that ADHD patients are impaired on tasks of behavioral inhibition, reward reversal, and working memory, which are functions of the prefrontal cortex (PFC) and are modulated by the mesocortical dopamine (DA) system. Non-specific electrical lesioning of PFC eliminated the expression of behavioral sensitization elicited by chronic MPD administration. Behavioral sensitization is the progressive augmentation of locomotor activity as a result of repetitive (chronic) exposure to the drug. It is believed that the sensitization to chronic drug treatment is caused due to an increase in DA in the mesocorticolimbic DA system, which includes the PFC. Therefore, this study investigated the role of PFC DA in mediating the behavioral sensitization to repeated administration of MPD in adult male Sprague-Dawley rats. On experimental day (ED) 1, the behavior was recorded post-saline injection. On ED 2, the rats were divided into three groups--control, sham and bilateral 6-OHDA treated group; and the sham and 6-OHDA treated groups underwent respective surgeries. After 5 days of rest following surgery, the post-surgery baseline was recorded on ED 8 following a saline injection. All three groups received 2.5 mg/kg MPD for 6 days (from ED 9 to ED 14), followed by a 3-day washout period (ED 15 to ED 18). On ED 19, a rechallenge injection of 2.5 mg/kg MPD was given and locomotor activity was recorded. It was found that the 6-OHDA lesion group failed to exhibit behavioral sensitization to MPD. The involvement of the dopaminergic afferents of PFC in behavioral sensitization to MPD is discussed.
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Affiliation(s)
- S J Wanchoo
- Department of Neurobiology and Anatomy, University of Texas Medical School at Houston, Houston, TX, USA
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Schaefers AT, Teuchert-Noodt G, Bagorda F, Brummelte S. Effect of postnatal methamphetamine trauma and adolescent methylphenidate treatment on adult hippocampal neurogenesis in gerbils. Eur J Pharmacol 2009; 616:86-90. [DOI: 10.1016/j.ejphar.2009.06.006] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2008] [Revised: 05/27/2009] [Accepted: 06/08/2009] [Indexed: 12/11/2022]
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Askenasy EP, Taber KH, Yang PB, Dafny N. METHYLPHENIDATE (RITALIN): BEHAVIORAL STUDIES IN THE RAT. Int J Neurosci 2009; 117:757-94. [PMID: 17454243 DOI: 10.1080/00207450600910176] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
Attention Deficit Hyperactivity Disorder (ADHD) is a neuropsychiatric syndrome with an onset in childhood characterized by an inability to remain focused or to concentrate for prolonged periods of time. Children suffering from this disease are many times described as either inattentive or as hyperactive-impulsive depending on what form of the disease they manifest. Methylphenidate is the preferred treatment for this behavioral disorder and is used for long term disease management. Much still remains unknown concerning this stimulant and its effects on behavior and future abuse potential are pertinent questions. Since animal models are used to study the mechanism of drug action and rats are used often in drug studies, the objective of this review is to summarize the research reports that mainly have used rats as the model to investigate the action of methylphenidate. Topics discussed in this review include: (1) What effect does a single dose of methylphenidate have on locomotion activity; (2) Does repeated administration of methylphenidate result in tolerance or sensitization; and (3) Does methylphenidate have rewarding properties as measured by the self-administration and condition placed preference paradigms.
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Affiliation(s)
- Erik P Askenasy
- Department of Neurobiology and Anatomy, University of Texas Medical School at Houston, Houston, Texas 77225, USA
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Lee MJ, Yang PB, Wilcox VT, Burau KD, Swann AC, Dafny N. Does repetitive Ritalin injection produce long-term effects on SD female adolescent rats? Neuropharmacology 2009; 57:201-7. [PMID: 19540860 DOI: 10.1016/j.neuropharm.2009.06.008] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2009] [Revised: 06/10/2009] [Accepted: 06/10/2009] [Indexed: 12/26/2022]
Abstract
Methylphenidate (MPD), or Ritalin, is a psychostimulant that is prescribed for an extended period of time to children and adolescents with attention deficit hyperactivity disorder. Adolescence is a time of critical brain maturation and development, and the drug exposure during this time could lead to lasting changes in the brain that endure into the adulthood. Circadian rhythms are 24 h rhythms of physiological processes that are synchronized by the master-clock, the suprachiasmatic nucleus, to keep the body stable in a changing environment. The aim of present study is to observe the effect of repeated MPD exposure on the locomotor diurnal rhythm activity patterns of female adolescent Sprague-Dawley (SD) rats using the open field assay. 31 female adolescent SD rats were divided into four groups: control, 0.6 mg/kg, 2.5 mg/kg, and 10 mg/kg MPD group. On experimental day 1, all groups were given an injection of saline. On experimental days 2-7, animals were injected once a day with either saline, 0.6 mg/kg, 2.5 mg/kg, or 10 mg/kg MPD, and experimental days 8-10 were the washout period. A re-challenge injection was given to each animal on experimental day 11 with the similar dose as the experimental days 2-7. The locomotor movements were counted by the computerized animal activity monitoring system. The data were analyzed statistically to find out whether the diurnal rhythm activity patterns were altered. The obtained data showed that repeated administrations of 2.5 mg/kg and 10 mg/kg MPD were able to change the locomotor diurnal rhythm patterns, which suggests that these MPD doses exerts long-term effects.
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Affiliation(s)
- Min J Lee
- Department of Neurobiology and Anatomy, The University of Texas, Medical School at Houston, Houston, TX 77225, United States
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Banerjee PS, Aston J, Khundakar AA, Zetterström TSC. Differential regulation of psychostimulant-induced gene expression of brain derived neurotrophic factor and the immediate-early gene Arc in the juvenile and adult brain. Eur J Neurosci 2009; 29:465-76. [PMID: 19222557 DOI: 10.1111/j.1460-9568.2008.06601.x] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
Psychostimulant drugs are widely used in children for the treatment of attention-deficit/hyperactivity disorder. Recent animal studies have suggested that exposure to these agents in early life could be detrimental to brain development. Here, for the first time, the effect of methylphenidate (MPH) and D-amphetamine (AMPH) on the expression of two key genes for neuronal development and plasticity, brain-derived neurotrophic factor (bdnf) and the effector immediate early gene activity-regulated, cytoskeletal-associated protein (Arc), was examined in both juvenile and adult rats. Both MPH [2 mg/kg, intraperitoneal (i.p.)] and AMPH (0.5 mg/kg, i.p.) induced marked decreases of bdnf mRNA in hippocampal and cortical brain regions of juveniles, whereas effects in adults were significantly less (hippocampus) or opposite (frontal cortex). In comparison, Arc mRNA was decreased (hippocampus and parietal cortex), largely unaffected (frontal cortex) or increased (striatum) in juveniles, whereas in adults, Arc mRNA increased in most brain regions. MPH-induced locomotion was also measured, and showed a much smaller increase in juveniles than in adults. In summary, our data show that the effects of MPH and AMPH on expression of the neurodevelopmentally important genes, bdnf and Arc, differ markedly in juvenile and adult rats, with juveniles showing evidence of brain region-specific decreases in both genes. These age-dependent effects on gene expression may be linked with the reported long-term harmful effects of psychostimulants in animal models.
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Affiliation(s)
- Partha S Banerjee
- Leicester School of Pharmacy, Faculty of Health and Life Sciences, De Montfort University, The Gateway, Leicester, UK
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Scaini G, Fagundes AO, Rezin GT, Gomes KM, Zugno AI, Quevedo J, Streck EL. Methylphenidate increases creatine kinase activity in the brain of young and adult rats. Life Sci 2008; 83:795-800. [PMID: 18938183 DOI: 10.1016/j.lfs.2008.09.019] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2008] [Revised: 08/12/2008] [Accepted: 09/22/2008] [Indexed: 12/25/2022]
Abstract
AIMS The high prevalence of Attention Deficit/Hyperactivity Disorder (ADHD) and the increased therapeutic use of methylphenidate (MPH) raise some concerns regarding its long-term side effects and safety profile. Considering that MPH effects on brain metabolism are poorly known and that creatine kinase (CK) plays an important role in cell energy homeostasis, we evaluated CK activity in the brain of young and adult rats following acute (one injection) or chronic (28 days) administration of MPH. MAIN METHODS MPH was acutely or chronically administered to young and adult rats. For acute administration, a single injection of MPH was given to rats on postnatal day (PD) 25 or PD 60, in the young and adult groups, respectively. For chronic administration, MPH injections were given to young rats starting at PD 25 once daily for 28 days (last injection at PD 53). In adult rats, the same regimen was performed starting at PD 60 (last injection at PD 88). CK activity was measured in brain homogenates. KEY FINDINGS Our results showed that MPH acute administration increased the enzyme in prefrontal cortex, hippocampus, striatum and cerebral cortex, but not cerebellum of young and adult rats. Chronic administration of MPH also increased CK activity in these brain regions, as well as the cerebellum, in young and adult rats. The highest dose (10.0 mg/kg) presented more pronouncing effects. SIGNIFICANCE The present findings suggest that acute or chronic exposure to MPH increased CK activity, an enzyme involved in energy homeostasis, in the brain of young and adult rats.
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Affiliation(s)
- Giselli Scaini
- Laboratório de Fisiopatologia Experimental, Programa de Pós-graduação em Ciências da Saúde, Universidade do Extremo Sul Catarinense, 88806-000 Criciúma, SC, Brazil
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Brummelte S, Grund T, Moll GH, Teuchert-Noodt G, Dawirs RR. Environmental enrichment has no effect on the development of dopaminergic and GABAergic fibers during methylphenidate treatment of early traumatized gerbils. J Negat Results Biomed 2008; 7:2. [PMID: 18485211 PMCID: PMC2412842 DOI: 10.1186/1477-5751-7-2] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2007] [Accepted: 05/16/2008] [Indexed: 02/04/2023] Open
Abstract
It is widely believed, that environmental factors play a crucial role in the etiology and outcome of psychiatric diseases such as Attention-Deficit/Hyperactivity Disorder (ADHD). A former study from our laboratory has shown that both methylphenidate (MP) and handling have a positive effect on the dopaminergic fiber density in the prefrontal cortex (PFC) of early traumatized gerbils (Meriones unguiculatus). The current study was performed to investigate if enriched environment during MP application has an additional influence on the dopaminergic and GABAergic fiber densities in the PFC and amygdala in this animal model. Animals received a single early dose of methamphetamine (MA; 50 mg/kg; i.p.) on postnatal day (PD) 14, which is known to cause multiple changes in the subsequent development of several neurotransmitter systems including the dopaminergic systems, and were then treated with oral daily applications of MP (5 mg/kg) from PD30–60. Animals treated this way were either transferred to an enriched environment after weaning (on PD30) or were kept under impoverished rearing conditions. There was no effect of an enriched environment on the dopaminergic or GABAergic fiber density neither in the PFC nor in the amygdala. With regard to former studies these results underline the particular impact of MP in the treatment of ADHD.
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Affiliation(s)
- Susanne Brummelte
- Department of Neuroanatomy/Cognitive Neuroscience, Faculty of Biology, University of Bielefeld, Universitätsstrasse 25, D-33615 Bielefeld, Germany.
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Chronic methylphenidate treatment during adolescence increases anxiety-related behaviors and ethanol drinking in adult spontaneously hypertensive rats. Behav Pharmacol 2008; 19:21-7. [DOI: 10.1097/fbp.0b013e3282f3cfbe] [Citation(s) in RCA: 58] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Sagvolden T, Xu T. l-Amphetamine improves poor sustained attention while d-amphetamine reduces overactivity and impulsiveness as well as improves sustained attention in an animal model of Attention-Deficit/Hyperactivity Disorder (ADHD). Behav Brain Funct 2008; 4:3. [PMID: 18215285 PMCID: PMC2265273 DOI: 10.1186/1744-9081-4-3] [Citation(s) in RCA: 65] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2007] [Accepted: 01/23/2008] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND ADHD is currently defined as a cognitive/behavioral developmental disorder where all clinical criteria are behavioral. Overactivity, impulsiveness, and inattentiveness are presently regarded as the main clinical symptoms. There is no biological marker, but there is considerable evidence to suggest that ADHD behavior is associated with poor dopaminergic and noradrenergic modulation of neuronal circuits that involve the frontal lobes. The best validated animal model of ADHD, the Spontaneously Hypertensive Rat (SHR), shows pronounced overactivity, impulsiveness, and deficient sustained attention. While dopamine release is decreased in SHR, norepinephrine concentrations are elevated. The primary objective of the present research was to test effects of a range of doses of the catecholamine agonists d- and l-amphetamine on ADHD-like symptoms in SHR. METHODS The present study tested behavioral effects of 0.64 to 1.91 mg/kg d-amphetamine; and 1.27 to 3.81 mg/kg l-amphetamine base/kg i.p. in male SHRs and their controls, the Wistar Kyoto rat (WKY). ADHD-like behavior was tested with a visual discrimination task measuring overactivity, impulsiveness and inattentiveness. RESULTS The striking impulsiveness, overactivity, and poorer sustained attention during baseline conditions in the SHR were improved by treatment with the amphetamine isomers. The dose-response curves were, however, different for the different behaviors. Most significantly, d-amphetamine reduced overactivity and impulsiveness more efficiently than comparable doses of l-amphetamine. The lowest dose of d-amphetamine and low-to-medium doses of l-amphetamine improved sustained attention. The highest dose of d-amphetamine used interfered with SHR behavior. A second study showed that the impaired sustained attention (percent correct lever choice) in the SHR was not due to impaired visual functions or poorer working memory. DISCUSSION The present results indicate that overactivity and impulsiveness may to some extent be associated with imbalances in neural circuits that differ from those causing poor sustained attention and that the two amphetamine isomers may affect the different neuromodulators differently. While d-amphetamine improved SHR overactivity, impulsiveness as well as sustained attention, the behavioral effects of l-amphetamine were relatively more specific for improving sustained attention than for the other 2 symptoms. Thus, while d- and l-amphetamine affect similar neuronal systems their relative potencies may be different.
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Affiliation(s)
- Terje Sagvolden
- Institute of Basic Medical Sciences, Department of Physiology, University of Oslo, PO Box 1103 Blindern, NO-0317 Oslo, Norway.
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Roessner V, Walitza S, Riederer F, Hünnerkopf R, Rothenberger A, Gerlach M, Moser A. Tetrahydroisoquinoline derivatives: a new perspective on monoaminergic dysfunction in children with ADHD? Behav Brain Funct 2007; 3:64. [PMID: 18070346 PMCID: PMC2222225 DOI: 10.1186/1744-9081-3-64] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2007] [Accepted: 12/10/2007] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND The dopamine-derived tetrahydroisoquinolines (TIQ) synthesized endogeneously from aldehydes and catecholamines have shown to modulate neurotransmission, central metabolism and motor activity. Converging evidence has implicated abnormalities of the dopamine metabolism to the pathophysiology of Attention-Deficit/Hyperactivity Disorder (ADHD). Therefore, four TIQ derivatives involved in central dopamine metabolism (salsolinol, N-methyl-salsolinol, norsalsolinol, N-methyl-norsalsolinol) have been analyzed for the first time in children and adolescents with ADHD and healthy controls. METHODS 42 children and adolescents with ADHD and 24 controls from three sites participated in this pilot study. Free and bound amounts of salsolinol, N-methyl-salsolinol, norsalsolinol, N-methyl-norsalsolinol have been analyzed in urine. RESULTS In the ADHD group, free and total amounts of the four TIQ derivatives in urine were significantly higher compared to urine levels of healthy controls. For N-methyl-salsolinolfree, most of the ADHD patients were identified correctly with a sensitivity of 92.5% (specificity 94.4%). CONCLUSION Urine levels of salsolinol, N-methyl-salsolinol, norsalsolinol and N-methyl-norsalsolinol are elevated in children and adolescents with ADHD and point to a new perspective on catecholaminergic dysfunction in ADHD. However, replication and extension of this pilot study would progress this innovative and promising field.
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Affiliation(s)
- Veit Roessner
- Department of Child and Adolescent Psychiatry, University of Goettingen, Goettingen, Germany.
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Long-term effects of methylphenidate on neural networks associated with executive attention in children with ADHD: results from a longitudinal functional MRI study. J Am Acad Child Adolesc Psychiatry 2007; 46:1633-41. [PMID: 18030085 DOI: 10.1097/chi.0b013e318157cb3b] [Citation(s) in RCA: 67] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
OBJECTIVE Little is known about the long-term effects of stimulants on the functional organization of the developing brain. Nonacute effects of stimulants on neural activity related to three aspects of attention (alerting, reorienting, and executive control) were examined in children with attention-deficit/hyperactivity disorder (ADHD) using a longitudinal functional magnetic resonance imaging approach. METHOD Nine boys with ADHD were scanned while drug naïve (t1) and after 1 year of methylphenidate treatment (t2). Eleven matched controls were also investigated twice. ADHD children stopped medication 1 week before t2. RESULTS Although all of the children showed stable alerting and reorienting performance from t1 to t2, normal controls significantly improved their executive control performance at t2, whereas children with ADHD did not. Neurally, controls showed a larger increase in neural activity from t1 to t2 in regions critical to task performance (i.e., in the temporoparietal junction during reorienting of attention and in the anterior cingulate cortex during executive control) compared to the patient group. However, only children with ADHD showed a decrease in neural activity in the insula and putamen during reorienting, indicating a reduction in compensatory brain activation over time. CONCLUSIONS These data suggest that 1 year of MPH treatment may be beneficial, albeit insufficient, to show enduring normalization of neural correlates of attention.
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Jezierski G, Zehle S, Bock J, Braun K, Gruss M. Early stress and chronic methylphenidate cross-sensitize dopaminergic responses in the adolescent medial prefrontal cortex and nucleus accumbens. J Neurochem 2007; 103:2234-44. [DOI: 10.1111/j.1471-4159.2007.04927.x] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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Gray JD, Punsoni M, Tabori NE, Melton JT, Fanslow V, Ward MJ, Zupan B, Menzer D, Rice J, Drake CT, Romeo RD, Brake WG, Torres-Reveron A, Milner TA. Methylphenidate administration to juvenile rats alters brain areas involved in cognition, motivated behaviors, appetite, and stress. J Neurosci 2007; 27:7196-207. [PMID: 17611273 PMCID: PMC6794586 DOI: 10.1523/jneurosci.0109-07.2007] [Citation(s) in RCA: 87] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Thousands of children receive methylphenidate (MPH; Ritalin) for attention deficit/hyperactivity disorder (ADHD), yet the long-term neurochemical consequences of MPH treatment are unknown. To mimic clinical Ritalin treatment in children, male rats were injected with MPH (5 mg/kg) or vehicle twice daily from postnatal day 7 (PND7)-PND35. At the end of administration (PND35) or in adulthood (PND135), brain sections from littermate pairs were immunocytochemically labeled for neurotransmitters and cytological markers in 16 regions implicated in MPH effects and/or ADHD etiology. At PND35, the medial prefrontal cortex (mPFC) of rats given MPH showed 55% greater immunoreactivity (-ir) for the catecholamine marker tyrosine hydroxylase (TH), 60% more Nissl-stained cells, and 40% less norepinephrine transporter (NET)-ir density. In hippocampal dentate gyrus, MPH-receiving rats showed a 51% decrease in NET-ir density and a 61% expanded distribution of the new-cell marker PSA-NCAM (polysialylated form of neural cell adhesion molecule). In medial striatum, TH-ir decreased by 21%, and in hypothalamus neuropeptide Y-ir increased by 10% in MPH-exposed rats. At PND135, MPH-exposed rats exhibited decreased anxiety in the elevated plus-maze and a trend for decreased TH-ir in the mPFC. Neither PND35 nor PND135 rats showed major structural differences with MPH exposure. These findings suggest that developmental exposure to high therapeutic doses of MPH has short-term effects on select neurotransmitters in brain regions involved in motivated behaviors, cognition, appetite, and stress. Although the observed neuroanatomical changes largely resolve with time, chronic modulation of young brains with MPH may exert effects on brain neurochemistry that modify some behaviors even in adulthood.
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Affiliation(s)
- Jason D. Gray
- Division of Neurobiology, Department of Neurology and Neuroscience and
| | - Michael Punsoni
- Division of Neurobiology, Department of Neurology and Neuroscience and
| | - Nora E. Tabori
- Division of Neurobiology, Department of Neurology and Neuroscience and
- Harold and Margaret Milliken Hatch Laboratory of Neuroendocrinology, The Rockefeller University, New York, New York 10021, and
| | - Jay T. Melton
- Division of Neurobiology, Department of Neurology and Neuroscience and
| | - Victoria Fanslow
- Division of Neurobiology, Department of Neurology and Neuroscience and
| | - Mary J. Ward
- Department of Pediatrics, Weill-Cornell Medical College, New York, New York 10021
| | - Bojana Zupan
- Division of Neurobiology, Department of Neurology and Neuroscience and
| | - David Menzer
- Division of Neurobiology, Department of Neurology and Neuroscience and
| | - Jackson Rice
- Division of Neurobiology, Department of Neurology and Neuroscience and
| | - Carrie T. Drake
- Division of Neurobiology, Department of Neurology and Neuroscience and
| | - Russell D. Romeo
- Harold and Margaret Milliken Hatch Laboratory of Neuroendocrinology, The Rockefeller University, New York, New York 10021, and
| | - Wayne G. Brake
- Centre for Studies in Behavioral Neurobiology, Department of Psychology, Concordia University, Montreal, Canada H4B 1R6
| | | | - Teresa A. Milner
- Division of Neurobiology, Department of Neurology and Neuroscience and
- Harold and Margaret Milliken Hatch Laboratory of Neuroendocrinology, The Rockefeller University, New York, New York 10021, and
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42
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Rüsch N, Weber M, Il'yasov KA, Lieb K, Ebert D, Hennig J, van Elst LT. Inferior frontal white matter microstructure and patterns of psychopathology in women with borderline personality disorder and comorbid attention-deficit hyperactivity disorder. Neuroimage 2007; 35:738-47. [PMID: 17289404 DOI: 10.1016/j.neuroimage.2006.12.007] [Citation(s) in RCA: 81] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2006] [Revised: 11/27/2006] [Accepted: 12/03/2006] [Indexed: 11/25/2022] Open
Abstract
BACKGROUND Inferior frontal white matter circuits are likely to be relevant to dysfunctional affect regulation, aggression, dissociative symptoms, neuropsychological functioning and psychopathology in women with borderline personality disorder (BPD) and comorbid attention-deficit hyperactivity disorder (ADHD). METHODS 20 women with BPD and comorbid ADHD and 20 healthy women were investigated, and groups were matched for age, education and premorbid intelligence. Mean diffusivity and fractional anisotropy were measured bilaterally in the inferior frontal white matter by diffusion tensor imaging (DTI). Conflict resolution was assessed by the Attention Network Test, sustained vigilance by the Degraded-Stimulus Continuous Performance Test. RESULTS Among women with BPD and comorbid ADHD, increased mean diffusivity in inferior frontal white matter was associated with higher levels of dysfunctional affect regulation, anger-hostility, dissociative symptoms, and general psychopathology (p<.05, uncorrected). Poor conflict resolution during the attention task was positively associated with anger-hostility, psychopathology, dissociation and the number of ADHD-symptoms, but not related to DTI variables. Both groups did not differ significantly with respect to DTI variables or neuropsychological performance. In the BPD group, a lifetime history of major depression or a current eating disorder were associated with impaired inferior frontal white matter integrity, while a history of sexual abuse or a current posttraumatic stress disorder were not. CONCLUSIONS Inferior frontal white matter microstructural abnormalities may be linked to key aspects of psychopathology in women with BPD and comorbid ADHD and add to alterations in orbitofrontal and limbic areas. The relationship between neuropsychological functioning and white matter structure remains unclear.
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Affiliation(s)
- Nicolas Rüsch
- Department of Psychiatry and Psychotherapy, University of Freiburg, Germany.
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43
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Zehle S, Bock J, Jezierski G, Gruss M, Braun K. Methylphenidate treatment recovers stress-induced elevated dendritic spine densities in the rodent dorsal anterior cingulate cortex. Dev Neurobiol 2007; 67:1891-900. [PMID: 17874461 DOI: 10.1002/dneu.20543] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Exposing pups of the rodent species Octodon degus to periodic separation stress during the first three postnatal weeks leads to behavioral alterations, which include reduced attention towards an emotional stimulus and motoric hyperactivity. These behavioral changes, which are reminiscent of symptoms of attention deficit hyperactivity disorder (ADHD), are paralleled by synaptic changes in the dorsal anterior cingulate cortex (ACd), a limbic cortex region, which plays a key role in the modulation of attentional and executive functions. ADHD is typically treated with methylphenidate (MP), a drug acting on the dopaminergic system. However, the effect of chronic MP-treatment on neuronal and synaptic maturation in the developing brain is unknown. Applying the Golgi-Cox stainining technique, we tested in which way chronic MP-treatment interferes with dendritic and synaptic development in the ACd and whether this treatment can restore the stress-induced changes of neuronal connectivity. We found that chronic treatment with 1 mg/kg MP recovers stress-induced changes of spine densities in the ACd. Furthermore, MP-treatment resulted in increased dendritic length and complexity in both, stressed as well as unstressed control animals. These results indicate that synaptic reorganization as well as dendritic growth in the prefrontal cortex continue into prepuberty and are modulated by MP-treatment.
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Affiliation(s)
- Stefanie Zehle
- Institute of Biology, Otto von Guericke University Magdeburg, Germany
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Brummelte S, Teuchert-Noodt G. Postnatal development of dopamine innervation in the amygdala and the entorhinal cortex of the gerbil (Meriones unguiculatus). Brain Res 2006; 1125:9-16. [PMID: 17112487 DOI: 10.1016/j.brainres.2006.10.006] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2006] [Revised: 10/03/2006] [Accepted: 10/03/2006] [Indexed: 11/16/2022]
Abstract
Dopamine (DA) projections from the mesencephalon are believed to play a critical role during development and are essential for cognitive and behavioral functions. Since the postnatal maturation patterns of these projections differ substantially between various brain regions, cortical, limbic or subcortical areas might exhibit varying vulnerabilities concerning developmental disorders. The dopaminergic afferents of the rodent prefrontal cortex show an extremely prolonged maturation which is very sensitive to epigenetic challenges. However, less is known about the development of the DA innervation of caudal limbic areas. Therefore, immunohistochemically stained DA fibers were quantitatively examined in the basolateral (BLA) and central amygdaloid nucleus (CE) and the ventrolateral entorhinal cortex (EC) of the Mongolian gerbil (Meriones unguiculatus). Animals of different ages, ranging from juvenile [postnatal day (PD) 14, 20, 30)] to adolescent (PD70), adult (6, 18 months) and aged (24 months), were analyzed. Results show a significant increase of fibers between PD14 and PD20 in the BLA and lateral part of the CE, with a trend for a subsequent decline in fiber densities until PD30. The EC and medial part of the CE showed no developmental changes. Interestingly, none of the investigated areas showed significant reductions of DA fibers during aging.
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Affiliation(s)
- Susanne Brummelte
- Department of Neuroanatomy, Faculty of Biology, University of Bielefeld, Universitätsstr. 25, D-33615 Bielefeld, Germany.
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Schneider M, Retz W, Coogan A, Thome J, Rösler M. Anatomical and functional brain imaging in adult attention-deficit/hyperactivity disorder (ADHD)--a neurological view. Eur Arch Psychiatry Clin Neurosci 2006; 256 Suppl 1:i32-41. [PMID: 16977550 DOI: 10.1007/s00406-006-1005-3] [Citation(s) in RCA: 83] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
In this review, we discuss current structural and functional imaging data on ADHD in a neurological and neuroanatomical framework. At present, the literature on adult ADHD is somewhat sparse, and so results from imaging have to therefore be considered mainly from the childhood or adolescence perspective. Most work has considered the impairment of executive functions (motor execution, inhibition, working memory), and as such a number of attention networks and their anatomical correlates are discussed in this review (e.g. the cerebello-(thalamo-)-striato-cortical network seems to play a pivotal role in ADHD pathology from childhood to adulthood). The core findings in ADHD imaging are alterations in the architecture and function of prefrontal cortex and cerebellum. The dorsal part of anterior cingulated cortex (dACC) is an important region for decision making, and executive control is impaired in adult ADHD. Finally, dysfunction of basal ganglia is a consistent finding in childhood and adulthood ADHD, reflecting dysregulation of fronto-striatal circuitry. The cerebellum, and its role in affect and cognition, is also persistently implicated in the pathology of ADHD.
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Affiliation(s)
- Marc Schneider
- Neurocentre/Institute of Forensic Psychology and Psychiatry, University of the Saarland, Building 90.3, 66421, Homburg/Saar, Germany.
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