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Yates JR. Aberrant glutamatergic systems underlying impulsive behaviors: Insights from clinical and preclinical research. Prog Neuropsychopharmacol Biol Psychiatry 2024; 135:111107. [PMID: 39098647 DOI: 10.1016/j.pnpbp.2024.111107] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/01/2024] [Revised: 07/07/2024] [Accepted: 07/24/2024] [Indexed: 08/06/2024]
Abstract
Impulsivity is a broad construct that often refers to one of several distinct behaviors and can be measured with self-report questionnaires and behavioral paradigms. Several psychiatric conditions are characterized by one or more forms of impulsive behavior, most notably the impulsive/hyperactive subtype of attention-deficit/hyperactivity disorder (ADHD), mood disorders, and substance use disorders. Monoaminergic neurotransmitters are known to mediate impulsive behaviors and are implicated in various psychiatric conditions. However, growing evidence suggests that glutamate, the major excitatory neurotransmitter of the mammalian brain, regulates important functions that become dysregulated in conditions like ADHD. The purpose of the current review is to discuss preclinical and clinical evidence linking glutamate to separate aspects of impulsivity, specifically motor impulsivity, impulsive choice, and affective impulsivity. Hyperactive glutamatergic activity in the corticostriatal and the cerebro-cerebellar pathways are major determinants of motor impulsivity. Conversely, hypoactive glutamatergic activity in frontal cortical areas and hippocampus and hyperactive glutamatergic activity in anterior cingulate cortex and nucleus accumbens mediate impulsive choice. Affective impulsivity is controlled by similar glutamatergic dysfunction observed for motor impulsivity, except a hyperactive limbic system is also involved. Loss of glutamate homeostasis in prefrontal and nucleus accumbens may contribute to motor impulsivity/affective impulsivity and impulsive choice, respectively. These results are important as they can lead to novel treatments for those with a condition characterized by increased impulsivity that are resistant to conventional treatments.
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Affiliation(s)
- Justin R Yates
- Department of Psychological Science, Northern Kentucky University, 1 Nunn Drive, Highland Heights, KY 41099, USA.
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2
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Emerging findings of glutamate-glutamine imbalance in the medial prefrontal cortex in attention deficit/hyperactivity disorder: systematic review and meta-analysis of spectroscopy studies. Eur Arch Psychiatry Clin Neurosci 2022; 272:1395-1411. [PMID: 35322293 DOI: 10.1007/s00406-022-01397-6] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/27/2021] [Accepted: 03/01/2022] [Indexed: 12/11/2022]
Abstract
One of the main challenges in investigating the neurobiology of ADHD is our limited capacity to study its neurochemistry in vivo. Magnetic resonance spectroscopy (MRS) estimates metabolite concentrations within the brain, but approaches and findings have been heterogeneous. To assess differences in brain metabolites between patients with ADHD and healthy controls, we searched 12 databases screening for MRS studies. Studies were divided into 'children and adolescents' and 'adults' and meta-analyses were performed for each brain region with more than five studies. The quality of studies was assessed by the Newcastle-Ottawa Scale. Thirty-three studies met our eligibility criteria, including 874 patients with ADHD. Primary analyses revealed that the right medial frontal area of children with ADHD presented higher concentrations of a composite of glutamate and glutamine (p = 0.02, SMD = 0.53). Glutamate might be implicated in pruning and neurodegenerative processes as an excitotoxin, while glutamine excess might signal a glutamate depletion that could hinder neurotrophic activity. Both neuro metabolites could be implicated in the differential cortical thinning observed in patients with ADHD across all ages. Notably, more homogeneous designs and reporting guidelines are the key factors to determine how suitable MRS is for research and, perhaps, for clinical psychiatry. Results of this meta-analysis provided an overall map of the brain regions evaluated so far, addressed the role of glutamatergic metabolites in the pathophysiology of ADHD, and pointed to new perspectives for consistent use of the tool in the field.
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3
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Maier S, Düppers AL, Runge K, Dacko M, Lange T, Fangmeier T, Riedel A, Ebert D, Endres D, Domschke K, Perlov E, Nickel K, Tebartz van Elst L. Increased prefrontal GABA concentrations in adults with autism spectrum disorders. Autism Res 2022; 15:1222-1236. [PMID: 35587691 DOI: 10.1002/aur.2740] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2021] [Accepted: 04/28/2022] [Indexed: 11/10/2022]
Abstract
The excitatory-inhibitory imbalance hypothesis postulates dysregulation of the gamma-aminobutyric acid (GABA) and glutamate (Glu) neurotransmitter systems as a common underlying deficit in individuals with autism spectrum disorders (ASD). Previous studies suggest an important role of these systems in the pathophysiology of ASD, including a study of our group reporting decreased glutamate concentrations in the pregenual anterior cingulate cortex (ACC) of adults with ASD. The aim of this study was to replicate our previous findings of impaired glutamate metabolism in ASD in a new sample and to additionally quantify GABA in the ACC and dorsolateral prefrontal cortex (dlPFC). Concentrations of GABA and glutamate-glutamine (Glx; combined glutamate and glutamine signal) were quantified in the ACC and dlPFC of 43 adults with ASD and 43 neurotypical controls (NTC) by magnetic resonance spectroscopy (MRS). The ASD group showed increased absolute GABA concentrations and elevated GABA/creatine ratios in the left dlPFC compared to NTC, while no group differences were detected in the pregenual and dorsal ACC. Previous findings of altered Glx concentration in the pregenual ACC of the ASD group could not be replicated. Regarding Glx concentrations and Glx/creatine ratios, there were no significant differences in the dlPFC and ACC either. The study supports the hypothesis of an altered GABA and glutamate equilibrium, indicating an imbalance between excitatory and inhibitory metabolism in ASD patients. However, inconsistent results across studies and brain regions suggest a complex underlying phenomenon. LAY SUMMARY: Adults of the autism spectrum exhibit elevated levels of the inhibitory neurotransmitter GABA in the left dorsolateral prefrontal cortex. This finding supports the hypothesis of an imbalance between excitatory and inhibitory equilibrium in patients with autism spectrum disorders.
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Affiliation(s)
- Simon Maier
- Section for Experimental Neuropsychiatry, Department of Psychiatry and Psychotherapy, Medical Center-University of Freiburg, Faculty of Medicine, University of Freiburg, Freiburg, Germany.,Department of Psychiatry and Psychotherapy, Medical Center-University of Freiburg, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | | | - Kimon Runge
- Section for Experimental Neuropsychiatry, Department of Psychiatry and Psychotherapy, Medical Center-University of Freiburg, Faculty of Medicine, University of Freiburg, Freiburg, Germany.,Department of Psychiatry and Psychotherapy, Medical Center-University of Freiburg, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Michael Dacko
- Department of Radiology, Medical Center-University of Freiburg, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Thomas Lange
- Department of Radiology, Medical Center-University of Freiburg, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Thomas Fangmeier
- Section for Experimental Neuropsychiatry, Department of Psychiatry and Psychotherapy, Medical Center-University of Freiburg, Faculty of Medicine, University of Freiburg, Freiburg, Germany.,Department of Psychiatry and Psychotherapy, Medical Center-University of Freiburg, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Andreas Riedel
- Section for Experimental Neuropsychiatry, Department of Psychiatry and Psychotherapy, Medical Center-University of Freiburg, Faculty of Medicine, University of Freiburg, Freiburg, Germany.,Luzerner Psychiatrie, Ambulante Dienste, Luzern, Switzerland
| | - Dieter Ebert
- Department of Psychiatry and Psychotherapy, Medical Center-University of Freiburg, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Dominique Endres
- Section for Experimental Neuropsychiatry, Department of Psychiatry and Psychotherapy, Medical Center-University of Freiburg, Faculty of Medicine, University of Freiburg, Freiburg, Germany.,Department of Psychiatry and Psychotherapy, Medical Center-University of Freiburg, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Katharina Domschke
- Department of Psychiatry and Psychotherapy, Medical Center-University of Freiburg, Faculty of Medicine, University of Freiburg, Freiburg, Germany.,Center for Basics in Neuromodulation, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Evgeniy Perlov
- Section for Experimental Neuropsychiatry, Department of Psychiatry and Psychotherapy, Medical Center-University of Freiburg, Faculty of Medicine, University of Freiburg, Freiburg, Germany.,Department of Psychiatry and Psychotherapy, Medical Center-University of Freiburg, Faculty of Medicine, University of Freiburg, Freiburg, Germany.,Clinic for Psychiatry Luzern, Hospital St. Urban, St. Urban, Switzerland
| | - Kathrin Nickel
- Section for Experimental Neuropsychiatry, Department of Psychiatry and Psychotherapy, Medical Center-University of Freiburg, Faculty of Medicine, University of Freiburg, Freiburg, Germany.,Department of Psychiatry and Psychotherapy, Medical Center-University of Freiburg, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Ludger Tebartz van Elst
- Section for Experimental Neuropsychiatry, Department of Psychiatry and Psychotherapy, Medical Center-University of Freiburg, Faculty of Medicine, University of Freiburg, Freiburg, Germany.,Department of Psychiatry and Psychotherapy, Medical Center-University of Freiburg, Faculty of Medicine, University of Freiburg, Freiburg, Germany
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4
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Boesen K, Paludan-Müller AS, Gøtzsche PC, Jørgensen KJ. Extended-release methylphenidate for attention deficit hyperactivity disorder (ADHD) in adults. Cochrane Database Syst Rev 2022; 2:CD012857. [PMID: 35201607 PMCID: PMC8869321 DOI: 10.1002/14651858.cd012857.pub2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
BACKGROUND Attention deficit hyperactivity disorder (ADHD) is a psychiatric diagnosis increasingly used in adults. The recommended first-line pharmacological treatment is central nervous system (CNS) stimulants, such as methylphenidate, but uncertainty remains about its benefits and harms. OBJECTIVES To assess the beneficial and harmful effects of extended-release formulations of methylphenidate in adults diagnosed with ADHD. SEARCH METHODS We searched CENTRAL, MEDLINE, Embase, nine other databases and four clinical trial registries up to February 2021. We searched 12 drug regulatory databases for clinical trial data up to 13 May 2020. In addition, we cross-referenced all available trial identifiers, handsearched reference lists, searched pharmaceutical company databases, and contacted trial authors. SELECTION CRITERIA Randomised, double-blind, parallel-group trials comparing extended-release methylphenidate formulations at any dose versus placebo and other ADHD medications in adults diagnosed with ADHD. DATA COLLECTION AND ANALYSIS Two review authors independently extracted data. We assessed dichotomous outcomes as risk ratios (RRs), and rating scales and continuous outcomes as mean differences (MDs) or standardised mean differences (SMDs). We used the Cochrane risk of bias tool to assess risks of bias, and GRADE to assess the certainty of the evidence. We meta-analysed the data using a random-effects model. We assessed three design characteristics that may impair the trial results' 'generalisability'; exclusion of participants with psychiatric comorbidity; responder selection based on previous experience with CNS stimulants; and risk of withdrawal effects. Our prespecified primary outcomes were functional outcomes, self-rated ADHD symptoms, and serious adverse events. Our secondary outcomes included quality of life, ADHD symptoms rated by investigators and by peers such as family members, cardiovascular variables, severe psychiatric adverse events, and other adverse events. MAIN RESULTS We included 24 trials (5066 participants), of which 21 reported outcome data for this review. We also identified one ongoing study. We included documents from six drug regulatory agencies covering eight trials. Twenty-one trials had an outpatient setting and three were conducted in prisons. They were primarily conducted in North America and Europe. The median participant age was 36 years. Twelve trials (76% of participants) were industry-sponsored, four (14% of participants) were publicly funded with industry involvement, seven (10% of participants) were publicly funded, and one had unclear funding. The median trial duration was eight weeks. One trial was rated at overall unclear risk of bias and 20 trials were rated at overall high risk of bias, primarily due to unclear blinding of participants and investigators, attrition bias, and selective outcome reporting. All trials were impaired in at least one of the three design characteristics related to 'generalisability'; for example, they excluded participants with psychiatric comorbidity such as depression or anxiety, or included participants only with a previous positive response to methylphenidate, or similar drugs. This may limit the trials' usefulness for clinical practice, as they may overestimate the benefits and underestimate the harms. Extended-release methylphenidate versus placebo (up to 26 weeks) For the primary outcomes, we found very low-certainty evidence that methylphenidate had no effect on 'days missed at work' at 13-week follow-up (mean difference (MD) -0.15 days, 95% confidence interval (CI) -2.11 to 1.81; 1 trial, 409 participants) or serious adverse events (risk ratio (RR) 1.43, CI 95% CI 0.85 to 2.43; 14 trials, 4078 participants), whereas methylphenidate improved self-rated ADHD symptoms (small-to-moderate effect; SMD -0.37, 95% CI -0.43 to -0.30; 16 trials, 3799 participants). For secondary outcomes, we found very low-certainty evidence that methylphenidate improved self-rated quality of life (small effect; SMD -0.15, 95% CI -0.25 to -0.05; 6 trials, 1888 participants), investigator-rated ADHD symptoms (small-to-moderate effect; SMD -0.42, 95% CI -0.49 to -0.36; 18 trials, 4183 participants), ADHD symptoms rated by peers such as family members (small-to-moderate effect; SMD -0.31, 95% CI -0.48 to -0.14; 3 trials, 1005 participants), and increased the risk of experiencing any adverse event (RR 1.27, 95% CI 1.19 to 1.37; 14 trials, 4214 participants). We rated the certainty of the evidence as 'very low' for all outcomes, primarily due to high risk of bias and 'indirectness of the evidence'. One trial (419 participants) had follow-up at 52 weeks and two trials (314 participants) included active comparators, hence long-term and comparative evidence is limited. AUTHORS' CONCLUSIONS We found very low-certainty evidence that extended-release methylphenidate compared to placebo improved ADHD symptoms (small-to-moderate effects) measured on rating scales reported by participants, investigators, and peers such as family members. Methylphenidate had no effect on 'days missed at work' or serious adverse events, the effect on quality of life was small, and it increased the risk of several adverse effects. We rated the certainty of the evidence as 'very low' for all outcomes, due to high risk of bias, short trial durations, and limitations to the generalisability of the results. The benefits and harms of extended-release methylphenidate therefore remain uncertain.
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Affiliation(s)
- Kim Boesen
- Meta-Research Innovation Center Berlin (METRIC-B), Berlin Institute of Health at Charité, QUEST Center for Responsible Research, Berlin, Germany
- Nordic Cochrane Centre, Rigshospitalet Dept 7811, Copenhagen, Denmark
| | - Asger Sand Paludan-Müller
- Centre for Evidence-Based Medicine Odense (CEBMO) and Cochrane Denmark, Department of Clinical Research, University of Southern Denmark, Odense, Denmark
- Open Patient data Exploratory Network (OPEN), Odense University Hospital, Odense, Denmark
| | | | - Karsten Juhl Jørgensen
- Centre for Evidence-Based Medicine Odense (CEBMO) and Cochrane Denmark, Department of Clinical Research, University of Southern Denmark, Odense, Denmark
- Open Patient data Exploratory Network (OPEN), Odense University Hospital, Odense, Denmark
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5
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Neuroimaging in Attention-Deficit/Hyperactivity Disorder: Recent Advances. AJR. AMERICAN JOURNAL OF ROENTGENOLOGY 2021; 218:321-332. [PMID: 34406053 DOI: 10.2214/ajr.21.26316] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Attention-deficit/hyperactivity disorder (ADHD) is a common neurodevelopmental condition, leading to impaired attention and impulsive behaviors diagnosed in, but not limited to, children. ADHD can cause symptoms throughout life. This article summarizes structural (conventional, volumetric, and diffusion tensor imaging MRI) and functional [task-based functional MRI (fMRI), resting state fMRI, PET, and MR spectroscopy] brain findings in patients with ADHD. Consensus is lacking regarding altered anatomic or functional imaging findings of the brain in children with ADHD, likely because of the disorder's heterogeneity. Most anatomic studies report abnormalities in the frontal lobes, basal ganglia, and corpus callosum; decreased surface area in the left ventral frontal and right prefrontal cortex; thinner medial temporal lobes; and smaller caudate nuclei. Using fMRI, researchers have focused on the prefrontal and temporal regions, reflecting perception-action mapping alterations. Artificial intelligence models evaluating brain anatomy have highlighted changes in cortical thickness and shape of the inferior frontal cortex, bilateral sensorimotor cortex, left temporal lobe, and insula. Early intervention and/or normal brain maturation can alter imaging patterns and convert functional imaging studies to a normal pattern. While the imaging findings provide insight into the disease's neuropathophysiology, no definitive structural or functional pattern defines the disorder from a neuroradiologic perspective.
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Alger JR, O'Neill J, O'Connor MJ, Kalender G, Ly R, Ng A, Dillon A, Narr KL, Loo SK, Levitt JG. Neuroimaging of Supraventricular Frontal White Matter in Children with Familial Attention-Deficit Hyperactivity Disorder and Attention-Deficit Hyperactivity Disorder Due to Prenatal Alcohol Exposure. Neurotox Res 2021; 39:1054-1075. [PMID: 33751467 PMCID: PMC8442735 DOI: 10.1007/s12640-021-00342-0] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2020] [Revised: 02/15/2021] [Accepted: 02/17/2021] [Indexed: 10/21/2022]
Abstract
Attention-deficit hyperactivity disorder (ADHD) is common in patients with (ADHD+PAE) and without (ADHD-PAE) prenatal alcohol exposure (PAE). Many patients diagnosed with idiopathic ADHD actually have covert PAE, a treatment-relevant distinction. To improve differential diagnosis, we sought to identify brain differences between ADHD+PAE and ADHD-PAE using neurobehavioral, magnetic resonance spectroscopy, and diffusion tensor imaging metrics that had shown promise in past research. Children 8-13 were recruited in three groups: 23 ADHD+PAE, 19 familial ADHD-PAE, and 28 typically developing controls (TD). Neurobehavioral instruments included the Conners 3 Parent Behavior Rating Scale and the Delis-Kaplan Executive Function System (D-KEFS). Two dimensional magnetic resonance spectroscopic imaging was acquired from supraventricular white matter to measure N-acetylaspartate compounds, glutamate, creatine + phosphocreatine (creatine), and choline-compounds (choline). Whole brain diffusion tensor imaging was acquired and used to to calculate fractional anisotropy, mean diffusivity, axial diffusivity, and radial diffusivity from the same superventricular white matter regions that produced magnetic resonance spectroscopy data. The Conners 3 Parent Hyperactivity/Impulsivity Score, glutamate, mean diffusivity, axial diffusivity, and radial diffusivity were all higher in ADHD+PAE than ADHD-PAE. Glutamate was lower in ADHD-PAE than TD. Within ADHD+PAE, inferior performance on the D-KEFS Tower Test correlated with higher neurometabolite levels. These findings suggest white matter differences between the PAE and familial etiologies of ADHD. Abnormalities detected by magnetic resonance spectroscopy and diffusion tensor imaging co-localize in supraventricular white matter and are relevant to executive function symptoms of ADHD.
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Affiliation(s)
- Jeffry R Alger
- Department of Neurology, University of California Los Angeles, MC 708522, Los Angeles, CA, 90024, USA.
- Neurospectroscopics, LLC, Sherman Oaks, CA, USA.
- Advanced Imaging Research Center, University of Texas Southwestern Medical Center, Dallas, TX, USA.
- Hura Imaging Inc, Calabas, CA, USA.
| | - Joseph O'Neill
- Division of Child & Adolescent Psychiatry, Jane & Terry Semel Instutute for Neuroscience and Human Behavior, University of California, Los Angeles, CA, USA
| | - Mary J O'Connor
- Division of Child & Adolescent Psychiatry, Jane & Terry Semel Instutute for Neuroscience and Human Behavior, University of California, Los Angeles, CA, USA
| | - Guldamla Kalender
- Division of Child & Adolescent Psychiatry, Jane & Terry Semel Instutute for Neuroscience and Human Behavior, University of California, Los Angeles, CA, USA
| | - Ronald Ly
- Division of Child & Adolescent Psychiatry, Jane & Terry Semel Instutute for Neuroscience and Human Behavior, University of California, Los Angeles, CA, USA
| | - Andrea Ng
- Division of Child & Adolescent Psychiatry, Jane & Terry Semel Instutute for Neuroscience and Human Behavior, University of California, Los Angeles, CA, USA
| | - Andrea Dillon
- Division of Child & Adolescent Psychiatry, Jane & Terry Semel Instutute for Neuroscience and Human Behavior, University of California, Los Angeles, CA, USA
| | - Katherine L Narr
- Department of Neurology, University of California Los Angeles, MC 708522, Los Angeles, CA, 90024, USA
- Division of Child & Adolescent Psychiatry, Jane & Terry Semel Instutute for Neuroscience and Human Behavior, University of California, Los Angeles, CA, USA
| | - Sandra K Loo
- Division of Child & Adolescent Psychiatry, Jane & Terry Semel Instutute for Neuroscience and Human Behavior, University of California, Los Angeles, CA, USA
| | - Jennifer G Levitt
- Division of Child & Adolescent Psychiatry, Jane & Terry Semel Instutute for Neuroscience and Human Behavior, University of California, Los Angeles, CA, USA
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7
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Mamiya PC, Arnett AB, Stein MA. Precision Medicine Care in ADHD: The Case for Neural Excitation and Inhibition. Brain Sci 2021; 11:brainsci11010091. [PMID: 33450814 PMCID: PMC7828220 DOI: 10.3390/brainsci11010091] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2020] [Revised: 12/15/2020] [Accepted: 01/11/2021] [Indexed: 12/14/2022] Open
Abstract
Attention-deficit/hyperactivity disorder (ADHD) is a neurodevelopmental disorder that has become increasingly prevalent worldwide. Its core symptoms, including difficulties regulating attention, activity level, and impulses, appear in early childhood and can persist throughout the lifespan. Current pharmacological options targeting catecholamine neurotransmissions have effectively alleviated symptoms in some, but not all affected individuals, leaving clinicians to implement trial-and-error approach to treatment. In this review, we discuss recent experimental evidence from both preclinical and human studies that suggest imbalance of excitation/inhibition (E/I) in the fronto-striatal circuitry during early development may lead to enduring neuroanatomical abnormality of the circuitry, causing persistence of ADHD symptoms in adulthood. We propose a model of precision medicine care that includes E/I balance as a candidate biomarker for ADHD, development of GABA-modulating medications, and use of magnetic resonance spectroscopy and scalp electrophysiology methods to monitor the effects of treatments on shifting E/I balance throughout the lifespan.
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Affiliation(s)
- Ping C. Mamiya
- Institute for Learning and Brain Sciences, University of Washington, Seattle, WA 98195, USA
- Correspondence:
| | - Anne B. Arnett
- Department of Psychiatry & Behavioral Sciences, University of Washington, Seattle, WA 98195, USA; (A.B.A.); (M.A.S.)
| | - Mark A. Stein
- Department of Psychiatry & Behavioral Sciences, University of Washington, Seattle, WA 98195, USA; (A.B.A.); (M.A.S.)
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8
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Maier S, Tebartz van Elst L, Philipsen A, Lange T, Feige B, Glauche V, Nickel K, Matthies S, Alm B, Sobanski E, Domschke K, Perlov E, Endres D. Effects of 12-Week Methylphenidate Treatment on Neurometabolism in Adult Patients with ADHD: The First Double-Blind Placebo-Controlled MR Spectroscopy Study. J Clin Med 2020; 9:jcm9082601. [PMID: 32796630 PMCID: PMC7464267 DOI: 10.3390/jcm9082601] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2020] [Revised: 06/26/2020] [Accepted: 06/29/2020] [Indexed: 11/27/2022] Open
Abstract
Attention deficit hyperactivity disorder (ADHD) is a frequent neurodevelopmental disorder that often persists into adulthood. Methylphenidate (MPH) is the first-line treatment for ADHD; however, despite its wide usage, little is known about its neurometabolic effects. Until now, no randomized and blinded clinical trials have been conducted addressing the neurometabolic signals of MPH administration in adults with ADHD. In the current study, the authors investigated how MPH intake and group psychotherapy (GPT) influence brain neurometabolism over the course of three months. The authors hypothesized a decrease in the anterior cingulate cortex (ACC) glutamate concentration following MPH administration. This study was part of a double-blind multicenter trial (Comparison of Methylphenidate and Psychotherapy in Adult ADHD Study (COMPAS)) investigating the effects of MPH and GPT in patients with adult ADHD. Using single-voxel magnetic resonance spectroscopy (MRS) of the pregenual ACC and the left cerebellar hemisphere (CHL), we investigated the concentration of glutamate plus glutamine (Glx), N-acetyl-aspartate, creatine, total choline containing compounds, and myo-inositol in patients before and after 12 weeks of treatment. Neither MPH nor GPT significantly influenced the Glx concentration or any of the other metabolite concentrations in the ACC and CHL after 12 weeks. Therefore, contrary to the hypothesis, no change in the prefrontal Glx signal was detected after MPH treatment. Given that MRS does not differentiate between glutamate in the synaptic cleft and in neuronal tissue, MPH-induced down-regulation of glutamatergic neurotransmission in the ACC might only affect the concentration of glutamate in the synaptic cleft, while the general availability of glutamate in the respective neuronal tissue might be unaffected by MPH intake. The observed lack of any MPH-induced normalization in metabolite concentrations is less surprising, considering that the baseline sample did not significantly differ from a healthy control group. Future studies of other regions, such as the basal ganglia, and the use of novel methods, such as whole brain MRS and multimodal imaging approaches, are necessary.
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Affiliation(s)
- Simon Maier
- Section for Experimental Neuropsychiatry, Department of Psychiatry and Psychotherapy, Medical Center—University of Freiburg, Faculty of Medicine, University of Freiburg, 79104 Freiburg, Germany; (S.M.); (B.F.); (K.N.); (E.P.); (D.E.)
- Department of Psychiatry and Psychotherapy, Medical Center—University of Freiburg, Faculty of Medicine, University of Freiburg, 79104 Freiburg, Germany; (S.M.); (K.D.)
| | - Ludger Tebartz van Elst
- Section for Experimental Neuropsychiatry, Department of Psychiatry and Psychotherapy, Medical Center—University of Freiburg, Faculty of Medicine, University of Freiburg, 79104 Freiburg, Germany; (S.M.); (B.F.); (K.N.); (E.P.); (D.E.)
- Department of Psychiatry and Psychotherapy, Medical Center—University of Freiburg, Faculty of Medicine, University of Freiburg, 79104 Freiburg, Germany; (S.M.); (K.D.)
- Correspondence:
| | - Alexandra Philipsen
- Department of Psychiatry and Psychotherapy, University Hospital Bonn, 53105 Bonn, Germany;
| | - Thomas Lange
- Department of Radiology, Medical Physics, Medical Center—University of Freiburg, Faculty of Medicine, University of Freiburg, 79106 Freiburg, Germany;
| | - Bernd Feige
- Section for Experimental Neuropsychiatry, Department of Psychiatry and Psychotherapy, Medical Center—University of Freiburg, Faculty of Medicine, University of Freiburg, 79104 Freiburg, Germany; (S.M.); (B.F.); (K.N.); (E.P.); (D.E.)
- Department of Psychiatry and Psychotherapy, Medical Center—University of Freiburg, Faculty of Medicine, University of Freiburg, 79104 Freiburg, Germany; (S.M.); (K.D.)
| | - Volkmar Glauche
- Department of Neurology, Medical Center—University of Freiburg, Faculty of Medicine, University of Freiburg, 79106 Freiburg, Germany;
| | - Kathrin Nickel
- Section for Experimental Neuropsychiatry, Department of Psychiatry and Psychotherapy, Medical Center—University of Freiburg, Faculty of Medicine, University of Freiburg, 79104 Freiburg, Germany; (S.M.); (B.F.); (K.N.); (E.P.); (D.E.)
- Department of Psychiatry and Psychotherapy, Medical Center—University of Freiburg, Faculty of Medicine, University of Freiburg, 79104 Freiburg, Germany; (S.M.); (K.D.)
| | - Swantje Matthies
- Department of Psychiatry and Psychotherapy, Medical Center—University of Freiburg, Faculty of Medicine, University of Freiburg, 79104 Freiburg, Germany; (S.M.); (K.D.)
| | - Barbara Alm
- Department of Psychiatry and Psychotherapy, Central Institute of Mental Health, Medical Faculty of Mannheim, University of Heidelberg, 68159 Mannheim, Germany; (B.A.); (E.S.)
| | - Esther Sobanski
- Department of Psychiatry and Psychotherapy, Central Institute of Mental Health, Medical Faculty of Mannheim, University of Heidelberg, 68159 Mannheim, Germany; (B.A.); (E.S.)
- Department of Child and Adolescent Psychiatry, University Medical Center Mainz, 55131 Mainz, Germany
| | - Katharina Domschke
- Department of Psychiatry and Psychotherapy, Medical Center—University of Freiburg, Faculty of Medicine, University of Freiburg, 79104 Freiburg, Germany; (S.M.); (K.D.)
- Center for Basics in Neuromodulation, Faculty of Medicine, University of Freiburg, 79106 Freiburg, Germany
| | - Evgeniy Perlov
- Section for Experimental Neuropsychiatry, Department of Psychiatry and Psychotherapy, Medical Center—University of Freiburg, Faculty of Medicine, University of Freiburg, 79104 Freiburg, Germany; (S.M.); (B.F.); (K.N.); (E.P.); (D.E.)
- Department of Psychiatry and Psychotherapy, Medical Center—University of Freiburg, Faculty of Medicine, University of Freiburg, 79104 Freiburg, Germany; (S.M.); (K.D.)
- Clinic for Psychiatry Luzern, St. Urban, 4915 Luzern, Switzerland
| | - Dominique Endres
- Section for Experimental Neuropsychiatry, Department of Psychiatry and Psychotherapy, Medical Center—University of Freiburg, Faculty of Medicine, University of Freiburg, 79104 Freiburg, Germany; (S.M.); (B.F.); (K.N.); (E.P.); (D.E.)
- Department of Psychiatry and Psychotherapy, Medical Center—University of Freiburg, Faculty of Medicine, University of Freiburg, 79104 Freiburg, Germany; (S.M.); (K.D.)
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Insular Cell Integrity Markers Linked to Weight Concern in Anorexia Nervosa-An MR-Spectroscopy Study. J Clin Med 2020; 9:jcm9051292. [PMID: 32365843 PMCID: PMC7288299 DOI: 10.3390/jcm9051292] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2020] [Revised: 04/27/2020] [Accepted: 04/28/2020] [Indexed: 12/29/2022] Open
Abstract
Objective: An insular involvement in the pathogenesis of anorexia nervosa (AN) has been suggested in many structural and functional neuroimaging studies. This magnetic resonance spectroscopy (MRS) study is the first to investigate metabolic signals in the anterior insular cortex in patients with AN and recovered individuals (REC). Method: The MR spectra of 32 adult women with AN, 21 REC subjects and 33 healthy controls (HC) were quantified for absolute N-acetylaspartate (NAA), glutamate + glutamine (Glx), total choline, myo-inositol, creatine concentrations (mM/L). After adjusting the metabolite concentrations for age and partial gray/white matter volume, group differences were tested using one-way multivariate analyses of variance (MANOVA). Post-hoc analyses of variance were applied to identify those metabolites that showed significant group effects. Correlations were tested for associations with psychometric measures (eating disorder examination), duration of illness, and body mass index. Results: The MANOVA exhibited a significant group effect. The NAA signal was reduced in the AN group compared to the HC group. The REC and the HC groups did not differ in metabolite concentrations. In the AN group, lower NAA and Glx signals were related to increased weight concern. Discussion: We interpret the decreased NAA availability in the anterior insula as a signal of impaired neuronal integrity or density. The association of weight concern, which is a core feature of AN, with decreased NAA and Glx indicates that disturbances of glutamatergic neurotransmission might be related to core psychopathology in AN. The absence of significant metabolic differences between the REC and HC subjects suggests that metabolic alterations in AN represent a state rather than a trait phenomenon.
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Hai T, Duffy H, Lemay JF, Swansburg R, Climie EA, MacMaster FP. Neurochemical Correlates of Executive Function in Children with Attention-Deficit/Hyperactivity Disorder. JOURNAL OF THE CANADIAN ACADEMY OF CHILD AND ADOLESCENT PSYCHIATRY = JOURNAL DE L'ACADEMIE CANADIENNE DE PSYCHIATRIE DE L'ENFANT ET DE L'ADOLESCENT 2020; 29:15-25. [PMID: 32194648 PMCID: PMC7065568] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 01/31/2019] [Accepted: 10/03/2019] [Indexed: 06/10/2023]
Abstract
OBJECTIVES Attention-Deficit/Hyperactivity Disorder (ADHD) is a prevalent neurodevelopmental disorder with no known biomarkers. The objectives of this study were 1) to investigate spectroscopic biomarkers in the right prefrontal cortex (R-PFC) and left striatum; 2) to evaluate Executive Function (EF) performance; and, 3) to examine the clinical relevance of glutamate in EF tasks. METHODS A total of 21 children with ADHD (M = 10.41 years, SD = 1.41) and 15 controls without ADHD (M = 9.90 years, SD = 1.54 years) were enrolled. Short echo proton magnetic resonance spectroscopy (1H-MRS; TE = 30ms) was used to study the changes in the R-PFC and left striatum. Both groups completed an EF assessment battery, including working memory, inhibition, cognitive flexibility and verbal fluency tasks. RESULTS In the R-PFC, independent t-tests found decreased concentration of glutamate (p = 0.009), NAA (p = 0.029) and choline (p = 0.016) in ADHD participants compared to controls. No significant differences were seen in the left striatum. Multivariate analysis of variance did not indicate overall EF challenges in the ADHD sample (p < .05). Positive correlations with glutamate concentration and EF performance in the control group were observed, however, no such correlations were reported in the ADHD group. CONCLUSIONS The results indicated a subgroup of children with ADHD who presented with hypo-glutamatergic signalling in the R-PFC. Additionally, findings suggested a decoupling effect of glutamate in EF related tasks in children with ADHD compared to controls. Thus, glutamate concentration may be a possible ADHD biomarker and novel treatments target.
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Affiliation(s)
- Tasmia Hai
- Werklund School of Education, University of Calgary, Calgary, Alberta
| | - Hanna Duffy
- Werklund School of Education, University of Calgary, Calgary, Alberta
| | | | - Rose Swansburg
- Cumming School of Medicine, University of Calgary, Calgary, Alberta
| | - Emma A Climie
- Werklund School of Education, University of Calgary, Calgary, Alberta
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Endres D, Tebartz van Elst L, Maier SJ, Feige B, Goll P, Meyer SA, Matthies S, Domschke K, Lange T, Sobanski E, Philipsen A, Nickel K, Perlov E. Neurochemical sex differences in adult ADHD patients: an MRS study. Biol Sex Differ 2019; 10:50. [PMID: 31665071 PMCID: PMC6821019 DOI: 10.1186/s13293-019-0264-4] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/02/2019] [Accepted: 08/30/2019] [Indexed: 12/17/2022] Open
Abstract
OBJECTIVE Attention-deficit/hyperactivity disorder (ADHD) is a common neurodevelopmental disorder. Relevant sex differences in symptomatology are discussed. This study compared brain neurometabolism in the anterior cingulate cortex (ACC) and left cerebellar hemisphere in age- and IQ-matched adult male (mADHD) and female (fADHD) ADHD patients. METHODS We studied 48 (ACC) and 42 (cerebellum) male/female pairs of stimulant-free patients with adult ADHD. Single voxel magnetic resonance spectroscopy (MRS) was used to investigate creatine (Cre), total choline (t-Cho), glutamate + glutamine (Glx), N-acetylaspartate, and myo-inositol. The mADHD and fADHD groups were compared using robust linear regression. The level of significance was corrected for multiple tests using the Benjamini-Hochberg approach. RESULTS For the ACC, the signals of Cre (p = 0.008) and t-Cho (p = 0.004) showed significant effects of the age covariate as well as an interaction of sex and age (Cre: p = 0.033; t-Cho: p = 0.040). For the Glx signal, an interaction of sex and age could also be observed (p = 0.033). For cerebellar neurometabolites, the signals of t-Cho (p = 0.049) and Glx (p = 0.049) showed significant effects of the factor sex. CONCLUSION This is the largest study yet to analyze sex differences in brain neurochemistry in adult patients with ADHD. Different age-dependent t-Cho signals in the ACC might be associated with delayed myelinization in mADHD. Further MRS studies in adult ADHD, accounting for possible sex effects, are warranted to validate the present findings.
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Affiliation(s)
- Dominique Endres
- Section for Experimental Neuropsychiatry, Department of Psychiatry and Psychotherapy, Medical Center—University of Freiburg, Faculty of Medicine, University of Freiburg, Freiburg, Germany
- Department of Psychiatry and Psychotherapy, Medical Center—University of Freiburg, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Ludger Tebartz van Elst
- Section for Experimental Neuropsychiatry, Department of Psychiatry and Psychotherapy, Medical Center—University of Freiburg, Faculty of Medicine, University of Freiburg, Freiburg, Germany
- Department of Psychiatry and Psychotherapy, Medical Center—University of Freiburg, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Simon J. Maier
- Section for Experimental Neuropsychiatry, Department of Psychiatry and Psychotherapy, Medical Center—University of Freiburg, Faculty of Medicine, University of Freiburg, Freiburg, Germany
- Department of Psychiatry and Psychotherapy, Medical Center—University of Freiburg, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Bernd Feige
- Section for Experimental Neuropsychiatry, Department of Psychiatry and Psychotherapy, Medical Center—University of Freiburg, Faculty of Medicine, University of Freiburg, Freiburg, Germany
- Department of Psychiatry and Psychotherapy, Medical Center—University of Freiburg, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Peter Goll
- Section for Experimental Neuropsychiatry, Department of Psychiatry and Psychotherapy, Medical Center—University of Freiburg, Faculty of Medicine, University of Freiburg, Freiburg, Germany
- Department of Psychiatry and Psychotherapy, Medical Center—University of Freiburg, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Simon A. Meyer
- Section for Experimental Neuropsychiatry, Department of Psychiatry and Psychotherapy, Medical Center—University of Freiburg, Faculty of Medicine, University of Freiburg, Freiburg, Germany
- Department of Psychiatry and Psychotherapy, Medical Center—University of Freiburg, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Swantje Matthies
- Department of Psychiatry and Psychotherapy, Medical Center—University of Freiburg, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Katharina Domschke
- Department of Psychiatry and Psychotherapy, Medical Center—University of Freiburg, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Thomas Lange
- Department of Radiology, Medical Physics, Medical Center—University of Freiburg, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Esther Sobanski
- Department of Psychiatry and Psychotherapy, Central Institute of Mental Health, Clinical Faculty Mannheim, University of Heidelberg, Mannheim, Germany
- Department of Child and Adolescent Psychiatry and Psychotherapy, University Medicine Mainz, Mainz, Germany
| | - Alexandra Philipsen
- Department of Psychiatry and Psychotherapy, University of Bonn, Bonn, Germany
| | - Kathrin Nickel
- Section for Experimental Neuropsychiatry, Department of Psychiatry and Psychotherapy, Medical Center—University of Freiburg, Faculty of Medicine, University of Freiburg, Freiburg, Germany
- Department of Psychiatry and Psychotherapy, Medical Center—University of Freiburg, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Evgeniy Perlov
- Section for Experimental Neuropsychiatry, Department of Psychiatry and Psychotherapy, Medical Center—University of Freiburg, Faculty of Medicine, University of Freiburg, Freiburg, Germany
- Department of Psychiatry and Psychotherapy, Medical Center—University of Freiburg, Faculty of Medicine, University of Freiburg, Freiburg, Germany
- Clinic for Psychiatry Luzern, St. Urban, Switzerland
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Bauer J, Werner A, Kohl W, Kugel H, Shushakova A, Pedersen A, Ohrmann P. Hyperactivity and impulsivity in adult attention-deficit/hyperactivity disorder is related to glutamatergic dysfunction in the anterior cingulate cortex. World J Biol Psychiatry 2018; 19:538-546. [PMID: 27973969 DOI: 10.1080/15622975.2016.1262060] [Citation(s) in RCA: 41] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
OBJECTIVES Attention-deficit/hyperactivity disorder (ADHD) is closely linked to the dysregulation of dopaminergic and noradrenergic neurotransmission in the fronto-striatal neural network, including the anterior cingulate cortex (ACC) and the dorsolateral prefrontal cortex (DLPFC). Additionally, increasing evidence supports the involvement of the glutamatergic system in the pathophysiology of ADHD. Impulsivity, a core symptom in patients with ADHD, has been repeatedly associated with glutamatergic neurotransmission, and pharmacological treatment of ADHD has been shown to reduce glutamate levels in the prefrontal cortex. METHODS We investigated glutamate levels in the ACC and the DLPFC in 30 adults with ADHD and 30 healthy controls using single-voxel proton magnetic resonance spectroscopy on a 3T scanner. RESULTS The ADHD group showed a significant increase in glutamate in the ACC compared to controls, no significant differences in metabolites were observed in the DLPFC. Overall, glutamate levels in the ACC were positively correlated with ADHD symptomatology, especially hyperactivity and impulsivity symptoms. CONCLUSIONS Increased levels of glutamate in the ACC, which were positively correlated with hyperactivity and impulsivity, support the hypothesis that dysfunctional glutamatergic neurotransmission is at least partially responsible for ADHD symptomatology. Modulation of glutamatergic neurotransmission might therefore be a promising avenue for future pharmacological interventions.
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Affiliation(s)
- Jochen Bauer
- a Institute for Clinical Radiology, School of Medicine , University of Muenster , Germany
| | - Anne Werner
- b Department of Psychiatry, School of Medicine , University of Muenster , Germany
| | - Waldemar Kohl
- b Department of Psychiatry, School of Medicine , University of Muenster , Germany
| | - Harald Kugel
- a Institute for Clinical Radiology, School of Medicine , University of Muenster , Germany
| | - Anna Shushakova
- c Clinical Psychology and Psychotherapy, Institute of Psychology , University of Kiel , Germany
| | - Anya Pedersen
- c Clinical Psychology and Psychotherapy, Institute of Psychology , University of Kiel , Germany
| | - Patricia Ohrmann
- b Department of Psychiatry, School of Medicine , University of Muenster , Germany
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Zimmer L. Contribution of Clinical Neuroimaging to the Understanding of the Pharmacology of Methylphenidate. Trends Pharmacol Sci 2017; 38:608-620. [PMID: 28450072 DOI: 10.1016/j.tips.2017.04.001] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2016] [Revised: 02/28/2017] [Accepted: 04/03/2017] [Indexed: 12/20/2022]
Abstract
Methylphenidate (MPH) is currently the most widely used molecule in the pharmacologic treatment of attention-deficit hyperactivity disorder (ADHD). Although experience of its application now extends over several decades, its psychotropic nature, prolonged use in children, and chemical relation to amphetamines still raise doubts in the minds of prescribers and the families of the patients. Brain imaging has shed considerable light on the neuropharmacology of MPH. The two main in vivo neuroimaging techniques are positron-emission tomography (PET) and magnetic resonance imaging (MRI), and these can be applied in both animal models and humans. The present review seeks to show how human molecular and functional imaging has contributed to determining not only the molecular targets of MPH, and the action kinetics of the various pharmaceutical forms available, but also the connectivity and brain networks activated by treatment. We also discuss the perspectives opened up by new hybrid PET-MRI techniques that enable multimodal tracking of the impact of methylphenidate on neurotransmission.
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Affiliation(s)
- Luc Zimmer
- Université Claude Bernard Lyon 1, Université de Lyon, Lyon, France; Centre d'Étude et de Recherche Multimodale et Pluridisciplinaire en Imagerie (CERMEP) Imaging Platform, Hospices Civils de Lyon, Bron, France; Lyon Neuroscience Research Center, Centre National de la Recherche Scientifique (CNRS), Institut National de la Santé et de la Recherche Médicale (INSERM), Lyon, France.
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Endres D, Maier S, Feige B, Posielski NA, Nickel K, Ebert D, Riedel A, Philipsen A, Perlov E, Tebartz van Elst L. Altered Intermittent Rhythmic Delta and Theta Activity in the Electroencephalographies of High Functioning Adult Patients with Autism Spectrum Disorder. Front Hum Neurosci 2017; 11:66. [PMID: 28265243 PMCID: PMC5316544 DOI: 10.3389/fnhum.2017.00066] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2016] [Accepted: 01/31/2017] [Indexed: 12/27/2022] Open
Abstract
Background: Autism spectrum disorder (ASD) is often associated with epilepsy. Previous studies have also shown increased rates of electroencephalographic (EEG) alteration in ASD patients without epilepsy. The aim of this study was to compare the rate of intermittent rhythmic delta and theta activity (IRDA/IRTA) events between high-functioning adult patients with ASD and matched healthy controls. Materials and Methods: Routine EEG records of 19 ASD patients and 19 matched controls were screened for IRDA/IRTA using a fully data driven analysis with fixed thresholds. IRDA/IRTA rates before and after hyperventilation (HV) as well as the HV-induced difference in IRDA/IRTA rates (HV difference) were analyzed. For inter-group measures, we used the Wilcoxon rank sum test. Results: Significantly increased HV difference was detected in the ASD group (p = 0.0497). However, the groups showed no difference in IRDA/IRTA rates before HV (p = 0.564) and after HV (p = 0.163). Conclusions: The lack of any group differences regarding IRDA/IRTA before HV might be related to the fact that we only studied non-secondary high-functioning autism in a small sample of epilepsy-free adult patients. A significantly increased HV difference might be regarded as a marker of subtle neuronal network instability possibly causing short-term disturbances via local area network inhibition and long-term effects via epileptic encephalopathy.
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Affiliation(s)
- Dominique Endres
- Section for Experimental Neuropsychiatry, Department for Psychiatry and Psychotherapy, University Medical Center Freiburg, University of Freiburg Freiburg, Germany
| | - Simon Maier
- Section for Experimental Neuropsychiatry, Department for Psychiatry and Psychotherapy, University Medical Center Freiburg, University of Freiburg Freiburg, Germany
| | - Bernd Feige
- Section for Experimental Neuropsychiatry, Department for Psychiatry and Psychotherapy, University Medical Center Freiburg, University of Freiburg Freiburg, Germany
| | - Nicole A Posielski
- Section for Experimental Neuropsychiatry, Department for Psychiatry and Psychotherapy, University Medical Center Freiburg, University of Freiburg Freiburg, Germany
| | - Kathrin Nickel
- Section for Experimental Neuropsychiatry, Department for Psychiatry and Psychotherapy, University Medical Center Freiburg, University of Freiburg Freiburg, Germany
| | - Dieter Ebert
- Section for Experimental Neuropsychiatry, Department for Psychiatry and Psychotherapy, University Medical Center Freiburg, University of Freiburg Freiburg, Germany
| | - Andreas Riedel
- Section for Experimental Neuropsychiatry, Department for Psychiatry and Psychotherapy, University Medical Center Freiburg, University of Freiburg Freiburg, Germany
| | - Alexandra Philipsen
- Medical Campus University of Oldenburg, School of Medicine and Health Sciences, Psychiatry and Psychotherapy-University Hospital, Karl-Jaspers-Klinik Bad Zwischenahn, Germany
| | - Evgeniy Perlov
- Section for Experimental Neuropsychiatry, Department for Psychiatry and Psychotherapy, University Medical Center Freiburg, University of Freiburg Freiburg, Germany
| | - Ludger Tebartz van Elst
- Section for Experimental Neuropsychiatry, Department for Psychiatry and Psychotherapy, University Medical Center Freiburg, University of Freiburg Freiburg, Germany
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15
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Endres D, Tebartz van Elst L, Meyer SA, Feige B, Nickel K, Bubl A, Riedel A, Ebert D, Lange T, Glauche V, Biscaldi M, Philipsen A, Maier SJ, Perlov E. Glutathione metabolism in the prefrontal brain of adults with high-functioning autism spectrum disorder: an MRS study. Mol Autism 2017; 8:10. [PMID: 28316774 PMCID: PMC5351053 DOI: 10.1186/s13229-017-0122-3] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2016] [Accepted: 02/14/2017] [Indexed: 12/12/2022] Open
Abstract
Background Autism spectrum disorder (ASD) is a neurodevelopmental disease characterized by difficulties in social communication, unusually restricted, repetitive behavior and interests, and specific abnormalities in language and perception. The precise etiology of ASD is still unknown and probably heterogeneous. In a subgroup of patients, toxic environmental exposure might lead to an imbalance between oxidative stress and anti-oxidant systems. Previous serum and postmortem studies measuring levels of glutathione (GSH), the main cellular free radical scavenger in the brain, have supported the hypothesis that this compound might play a role in the pathophysiology of autism. Methods Using the method of single-voxel proton magnetic resonance spectroscopy (MRS), we analyzed the GSH signal in the dorsal anterior cingulate cortex (dACC) and the dorsolateral prefrontal cortex (DLPFC) of 24 ASD patients with normal or above average IQs and 18 matched control subjects. We hypothesized that we would find decreased GSH concentrations in both regions. Results We did not find overall group differences in neurometabolites including GSH, neither in the dorsal ACC (Wilks’ lambda test; p = 0.429) nor in the DLPFC (p = 0.288). In the dACC, we found a trend for decreased GSH signals in ASD patients (p = 0.076). Conclusions We were unable to confirm our working hypothesis regarding decreased GSH concentrations in the ASD group. Further studies combining MRS, serum, and cerebrospinal fluid measurements of GSH metabolism including other regions of interest or even whole brain spectroscopy are needed.
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Affiliation(s)
- Dominique Endres
- Section for Experimental Neuropsychiatry, Department of Psychiatry, Medical Center University of Freiburg, Faculty of Medicine, University of Freiburg, Hauptstr. 5, 79104 Freiburg, Germany
| | - Ludger Tebartz van Elst
- Section for Experimental Neuropsychiatry, Department of Psychiatry, Medical Center University of Freiburg, Faculty of Medicine, University of Freiburg, Hauptstr. 5, 79104 Freiburg, Germany
| | - Simon A Meyer
- Section for Experimental Neuropsychiatry, Department of Psychiatry, Medical Center University of Freiburg, Faculty of Medicine, University of Freiburg, Hauptstr. 5, 79104 Freiburg, Germany
| | - Bernd Feige
- Section for Experimental Neuropsychiatry, Department of Psychiatry, Medical Center University of Freiburg, Faculty of Medicine, University of Freiburg, Hauptstr. 5, 79104 Freiburg, Germany
| | - Kathrin Nickel
- Section for Experimental Neuropsychiatry, Department of Psychiatry, Medical Center University of Freiburg, Faculty of Medicine, University of Freiburg, Hauptstr. 5, 79104 Freiburg, Germany
| | - Anna Bubl
- Department for Psychiatry and Psychotherapy, Saarland University Medical Center, Kirrberger Str. 100, 66421 Homburg, Saar Germany
| | - Andreas Riedel
- Section for Experimental Neuropsychiatry, Department of Psychiatry, Medical Center University of Freiburg, Faculty of Medicine, University of Freiburg, Hauptstr. 5, 79104 Freiburg, Germany
| | - Dieter Ebert
- Section for Experimental Neuropsychiatry, Department of Psychiatry, Medical Center University of Freiburg, Faculty of Medicine, University of Freiburg, Hauptstr. 5, 79104 Freiburg, Germany
| | - Thomas Lange
- Department of Radiology, Medical Physics, Medical Center University of Freiburg, Faculty of Medicine, University of Freiburg, Breisacher Str. 60a, 79106 Freiburg, Germany
| | - Volkmar Glauche
- Department of Neurology, Medical Center University of Freiburg, Faculty of Medicine, University of Freiburg, Breisacher Str. 64, 79106 Freiburg, Germany
| | - Monica Biscaldi
- Department for Child and Adolescent Psychiatry and Psychotherapy, Medical Center University of Freiburg, Faculty of Medicine, University of Freiburg, Hauptstr. 8, 79104 Freiburg, Germany
| | - Alexandra Philipsen
- School of Medicine and Health Sciences, Psychiatry and Psychotherapy - University Hospital, Karl-Jaspers-Klinik, Medical Campus University of Oldenburg, Hermann-Ehlers-Str. 7, 26160 Bad Zwischenahn, Germany
| | - Simon J Maier
- Section for Experimental Neuropsychiatry, Department of Psychiatry, Medical Center University of Freiburg, Faculty of Medicine, University of Freiburg, Hauptstr. 5, 79104 Freiburg, Germany
| | - Evgeniy Perlov
- Section for Experimental Neuropsychiatry, Department of Psychiatry, Medical Center University of Freiburg, Faculty of Medicine, University of Freiburg, Hauptstr. 5, 79104 Freiburg, Germany.,Clinic for Psychiatry Luzern, Schafmattstrasse 1, 4915 St. Urban, Switzerland
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Endres D, Tebartz van Elst L, Feige B, Backenecker S, Nickel K, Bubl A, Lange T, Mader I, Maier S, Perlov E. On the Effect of Sex on Prefrontal and Cerebellar Neurometabolites in Healthy Adults: An MRS Study. Front Hum Neurosci 2016; 10:367. [PMID: 27531975 PMCID: PMC4969301 DOI: 10.3389/fnhum.2016.00367] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2016] [Accepted: 07/11/2016] [Indexed: 11/13/2022] Open
Abstract
In neuropsychiatric research, the aspects of sex have received increasing attention over the past decade. With regard to the neurometabolic differences in the prefrontal cortex and the cerebellum of both men and women, we performed a magnetic resonance spectroscopic (MRS) study of a large group of healthy subjects. For neurometabolic measurements, we used single-voxel proton MRS. The voxels of interest (VOI) were placed in the pregenual anterior cingulate cortex (pACC) and the left cerebellar hemisphere. Absolute quantification of creatine (Cre), total choline (t-Cho), glutamate and glutamine (Glx), N-acetylaspartate, and myo-inositol (mI) was performed. Thirty-three automatically matched ACCs and 31 cerebellar male-female pairs were statistically analyzed. We found no significant neurometabolic differences in the pACC region (Wilks' lambda: p = 0.657). In the left cerebellar region, we detected significant variations between the male and female groups (p = 0.001). Specifically, we detected significantly higher Cre (p = 0.005) and t-Cho (p = 0.000) levels in men. Additionally, males tended to have higher Glx and mI concentrations. This is the first study to report neurometabolic sex differences in the cerebellum. The effects of sexual hormones might have influenced our findings. Our data indicates the importance of adjusting for the confounding effects of sex in MRS studies.
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Affiliation(s)
- Dominique Endres
- Section for Experimental Neuropsychiatry, Department for Psychiatry and Psychotherapy, University Medical Center Freiburg Freiburg, Germany
| | - Ludger Tebartz van Elst
- Section for Experimental Neuropsychiatry, Department for Psychiatry and Psychotherapy, University Medical Center Freiburg Freiburg, Germany
| | - Bernd Feige
- Section for Experimental Neuropsychiatry, Department for Psychiatry and Psychotherapy, University Medical Center Freiburg Freiburg, Germany
| | - Stephan Backenecker
- Section for Experimental Neuropsychiatry, Department for Psychiatry and Psychotherapy, University Medical Center Freiburg Freiburg, Germany
| | - Kathrin Nickel
- Section for Experimental Neuropsychiatry, Department for Psychiatry and Psychotherapy, University Medical Center Freiburg Freiburg, Germany
| | - Anna Bubl
- Department for Psychiatry and Psychotherapy, Saarland University Medical Center Homburg, Germany
| | - Thomas Lange
- Department for Radiology, Medical Physics, University Medical Center Freiburg Freiburg, Germany
| | - Irina Mader
- Department of Neuroradiology, University Medical Center Freiburg Freiburg, Germany
| | - Simon Maier
- Section for Experimental Neuropsychiatry, Department for Psychiatry and Psychotherapy, University Medical Center Freiburg Freiburg, Germany
| | - Evgeniy Perlov
- Section for Experimental Neuropsychiatry, Department for Psychiatry and Psychotherapy, University Medical Center Freiburg Freiburg, Germany
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Attention-Deficit/Hyperactivity Disorder: Focus upon Aberrant N-Methyl-D-Aspartate Receptors Systems. Curr Top Behav Neurosci 2015; 29:295-311. [PMID: 26718589 DOI: 10.1007/7854_2015_415] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Attention-deficit/hyperactivity disorder (ADHD) pathophysiology persists in an obscure manner with complex interactions between symptoms, staging, interventions, genes, and environments. Only on the basis of increasing incidence of the disorder, the need for understanding is greater than ever. The notion of an imbalance between central inhibitory/excitatory neurotransmitters is considered to exert an essential role. In this chapter, we first review how the default mode network functions and dysfunction in individuals diagnosed with ADHD. We also present and briefly review some of the animal models used to examine the neurobiological aspects of ADHD. There is much evidence indicating that compounds/interventions that antagonize/block glutamic acid receptors and/or block the glutamate signal during the "brain growth spurt" or in the adult animal may induce functional and biomarker deficits. Additionally, we present evidence suggesting that animals treated with glutamate blockers at the period of the "brain growth spurt" fail to perform the exploratory activity, observed invariably with control mice, that is associated with introduction to a novel environment (the test cages). Later, when the control animals show less locomotor and rearing activity, i.e., interest in the test cages, the MK-801, ketamine and ethanol treated mice showed successively greater levels of locomotion and rearing (interest), i.e., they fail to "habituate" effectively, implying a cognitive dysfunction. These disturbances of glutamate signaling during a critical period of brain development may contribute to the ADHD pathophysiology. As a final addition, we have briefly identified new research venues in the interaction between ADHD, molecular studies, and personality research.
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