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Itagaki S, Ohnishi T, Toda W, Sato A, Matsumoto J, Ito H, Ishii S, Yamakuni R, Miura I, Yabe H. Reduced dopamine transporter availability in drug-naive adult attention-deficit/hyperactivity disorder. PCN REPORTS : PSYCHIATRY AND CLINICAL NEUROSCIENCES 2024; 3:e177. [PMID: 38868484 PMCID: PMC11114433 DOI: 10.1002/pcn5.177] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/24/2023] [Revised: 01/11/2024] [Accepted: 02/05/2024] [Indexed: 06/14/2024]
Abstract
Aim This study aimed to clarify the abnormalities in dopamine transporter (DAT) availability in drug-naive adult patients with attention-deficit/hyperactivity disorder (ADHD) and the relationship between ADHD symptoms and abnormalities in DAT availability. Methods Single-photon emission tomography (SPECT) was performed using iodine-123-β-carbomethoxy-3β-(4-iodophenyltropane) (I-123 β CIT) as a tracer to measure in vivo DAT availability in 20 drug-naive patients with ADHD [mean age ± standard deviation (SD)]: 25 ± 3.44 years; male:female = 11:9] and 20 age- and sex-matched healthy controls (HCs) (mean age ± SD: 23.9 ± 2.27 years). Comparisons of DAT availability between HCs and adult patients with ADHD and the association between symptom severity and DAT availability within the ADHD group were analyzed using Statistical Parametric Mapping 12. Results Drug-naive adults with ADHD showed significantly reduced DAT availability in the bilateral nucleus accumbens compared with HCs. Correlation analyses revealed a negative correlation between the severity of inattentive symptoms in adult patients with ADHD and DAT availability in the bilateral heads of the caudate nucleus, indicating the association between severe inattentive symptoms and lower DAT availability in the caudate nucleus. Conclusion In drug-naive adult patients with ADHD, DAT availability was reduced in the nucleus accumbens, an important part of the reward system. This finding indicates the importance of the DAT in the reward system in the pathogenesis of ADHD. Inattentiveness was associated with DAT availability in the caudate nucleus, suggesting involvement of the cortico-striato-thalamo-cortical circuit.
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Affiliation(s)
- Shuntaro Itagaki
- Department of NeuropsychiatryFukushima Medical UniversityFukushimaJapan
| | - Takashi Ohnishi
- Medical Affairs DivisionJanssen Pharmaceutical K.KTokyoJapan
| | - Wataru Toda
- Department of NeuropsychiatryFukushima Medical UniversityFukushimaJapan
| | - Aya Sato
- Department of NeuropsychiatryFukushima Medical UniversityFukushimaJapan
| | - Junya Matsumoto
- Department of NeuropsychiatryFukushima Medical UniversityFukushimaJapan
- Department of Pathology of Mental Diseases, National Institute of Mental HealthNational Center of Neurology and PsychiatryTokyoJapan
| | - Hiroshi Ito
- Department of Radiology and Nuclear MedicineFukushima Medical UniversityFukushimaJapan
| | - Shiro Ishii
- Department of Radiology and Nuclear MedicineFukushima Medical UniversityFukushimaJapan
| | - Ryo Yamakuni
- Department of Radiology and Nuclear MedicineFukushima Medical UniversityFukushimaJapan
| | - Itaru Miura
- Department of NeuropsychiatryFukushima Medical UniversityFukushimaJapan
| | - Hirooki Yabe
- Department of NeuropsychiatryFukushima Medical UniversityFukushimaJapan
- Department of Mind & Brain MedicineFukushima Medical UniversityFukushimaJapan
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Tokko T, Miškinyte G, Eensoo D, Harro J. Driving risks of young drivers with symptoms of attention deficit hyperactivity disorder: association with the dopamine transporter gene VNTR polymorphism. Nord J Psychiatry 2022; 76:575-583. [PMID: 35130472 DOI: 10.1080/08039488.2022.2032330] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
BACKGROUND Road traffic injuries are a leading cause of death for young adults, and young drivers with higher expression of symptoms of attention deficit-hyperactivity disorder (ADHD) could pose an even greater risk in traffic. Dopaminergic dysfunction has been found to occur in ADHD, with the dopamine transporter (DAT) gene VNTR polymorphism (DAT1 VNTR; rs28363170) being one of the most consistent genetic markers. Thus, we aimed at clarifying how the ADHD symptoms and the DAT1 VNTR relate to risk-taking behaviour in traffic, impulsivity and driving anger in young drivers. METHOD We used data of two traffic behaviour study samples (n = 741, mean age = 23.3 ± 7.2 years; n = 995, mean age = 22.9 ± 8.1 years) and the Estonian Children Personality Behaviour and Health Study (ECPBHS; traffic behaviour data n = 1,016, mean age = 25.2 ± 2.1 years). ADHD symptoms were assessed by self-report with the Adult ADHD Self-Report Scale (ASRS v1.1) and impulsivity with the Adaptive and Maladaptive Impulsivity Scale. Traffic behavioural measures were either self-reported (Driver Behaviour Questionnaire, Driving Anger Scale) or obtained from databases (registered accidents and violations). RESULTS Drivers with more self-reported ADHD symptoms also reported more risk-taking in traffic and had more of recorded traffic accidents and violations. DAT1 9 R carriers had a higher probability of high traffic risk behaviour only if they also had ADHD symptoms. CONCLUSION Higher level of ADHD symptoms is a significant risk factor in traffic, and carrying of the DAT1 9 R allele appears to aggravate these risks.
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Affiliation(s)
- Tõnis Tokko
- Department of Psychology, University of Tartu, Tartu, Estonia
| | - Grete Miškinyte
- Department of Psychology, University of Tartu, Tartu, Estonia
| | - Diva Eensoo
- Department of Chronic Diseases, Research Centre, National Institute for Health Development, Tallinn, Estonia
| | - Jaanus Harro
- Department of Neuropsychopharmacology, Institute of Chemistry, University of Tartu, Tartu, Estonia
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DNA Methylation and Allelic Polymorphism at the Dopamine Transporter Promoter Affect Internalizing and Externalizing Symptoms in Preschoolers. Child Psychiatry Hum Dev 2021; 52:281-290. [PMID: 32462358 DOI: 10.1007/s10578-020-01009-1] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
The role of the dopamine transporter (DAT) in the onset and maintenance of emotional-behavioral difficulties is recognized in adults, adolescents and school-age children, whereas few studies in this field have focused on preschoolers. The study recruited 2-year old children (N = 152) in the general population assessing the possible effect of DAT methylation and allelic polymorphism on internalizing and externalizing symptoms, also exploring whether epigenetic and genetic variability interact. Our results showed that DAT methylation is significantly associated with all the dimensions of children's emotional/behavioral functioning in children carrying 10/10-3/3-8/10 polymorphisms but not in children carrying 9/10-9/9 allele repeats. Understanding the influence of genetic/epigenetic factors on maladaptive emotional/behavioral outcomes in young children, can be of great help in programming effective prevention and intervention plans and can be a valid aid to alleviate psychopathological symptoms before they crystalize into more severe clinical conditions in later life.
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Akay AP, Kaya GÇ, Kose S, Yazıcıoğlu ÇE, Erkuran HÖ, Güney SA, Oğuz K, Keskin D, Baykara B, Emiroğlu Nİ, Eren MŞ, Kızıldağ S, Ertay T, Özsoylu D, Miral S, Durak H, Gönül AS, Rohde LA. Genetic imaging study with [Tc- 99m] TRODAT-1 SPECT in adolescents with ADHD using OROS-methylphenidate. Prog Neuropsychopharmacol Biol Psychiatry 2018; 86:294-300. [PMID: 29684537 DOI: 10.1016/j.pnpbp.2018.04.008] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/21/2017] [Revised: 04/11/2018] [Accepted: 04/18/2018] [Indexed: 01/13/2023]
Abstract
AIM To examine theeffects on the brain of 2-month treatment withamethylphenidate extended-release formulation (OROS-MPH) using [Tc-99m] TRODAT-1SPECT in a sample of treatment-naïve adolescents with Attention Deficit/Hyperactivity Disorder (ADHD). In addition, to assess whether risk alleles (homozygosity for 10-repeat allele at the DAT1 gene were associated with alterations in striatal DAT availability. METHODS Twenty adolescents with ADHD underwent brain single-photon emission computed tomography (SPECT) scans with [Tc-99m] TRODAT-1 at baseline and two months after starting OROS-MPH treatment with dosages up to 1 mg/kg/day. Severity of illness was estimated using the Clinical Global Impression Scale (CGI-S) and DuPaul ADHD Rating Scale-Clinician version (ARS) before treatment,1 month and 2 months after initiating OROS-MPH treatment. RESULTS Decreased DAT availability was found in both the right caudate (pretreatment DAT binding: 224.76 ± 33.77, post-treatment DAT binding: 208.86 ± 28.75, p = 0.02) and right putamen (pre-treatment DAT binding: 314.41 ± 55.24, post-treatment DAT binding: 285.66 ± 39.20, p = 0.05) in adolescents with ADHD receiving OROS-MPH treatment. Adolescents with ADHD who showed a robust response to OROS-MPH (n = 7) had significantly greater reduction of DAT density in the right putamen than adolescents who showed less robust response to OROS-MPH (n = 13) (p = 0.02). However, between-group differences by treatment responses were not related with DAT density in the right caudate. Risk alleles (homozygosity for the 10-repeat allele of DAT1 gene) in the DAT1 gene were not associated with alterations in striatal DAT availability. CONCLUSION Two months of OROS-MPH treatment decreased DAT availability in both the right caudate and putamen. Adolescents with ADHD who showed a robust response to OROS-MPH had greater reduction of DAT density in the right putamen. However,our findings did not support an association between homozygosity for a 10-repeat allele in the DAT1 gene and DAT density, assessedusing[Tc-99m] TRODAT-1SPECT.
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Affiliation(s)
- Aynur Pekcanlar Akay
- Deparment of Child and Adolescent Psychiatry, Dokuz Eylul University, Izmir, Turkey.
| | - Gamze Çapa Kaya
- Deparment of Nuclear Medicine, Dokuz Eylul University, Izmir, Turkey
| | - Samet Kose
- Department of Psychology, H. Kalyoncu University, Gaziantep, Turkey; Medical School of Houston, Center for Neurobehavioral Research on Addictions, University of Texas, Houston, TX, USA
| | | | - Handan Özek Erkuran
- Dr.Behçet Uz Pediatrics, Pediatric Surgery Research andTraining Hospital, Deparment of Child and Adolescent Psychiatry, Izmir, Turkey.
| | - Sevay Alşen Güney
- Deparment of Child and Adolescent Psychiatry, Dokuz Eylul University, Izmir, Turkey
| | - Kaya Oğuz
- Department of Computer Engineering, Izmir University of Economics, Izmir, Turkey
| | - Duygu Keskin
- Deparment of Psychiatry, EgianUniversity, Izmir, Turkey
| | - Burak Baykara
- Deparment of Child and Adolescent Psychiatry, Dokuz Eylul University, Izmir, Turkey
| | | | - Mine Şencan Eren
- Deparment of Nuclear Medicine, Dokuz Eylul University, Izmir, Turkey
| | - Sefa Kızıldağ
- Deparment of Molecular Biology and Genetics, Dokuz Eylul University, Izmir,Turkey
| | - Türkan Ertay
- Deparment of Nuclear Medicine, Dokuz Eylul University, Izmir, Turkey
| | - Dua Özsoylu
- Deparment of Molecular Biology and Genetics, Dokuz Eylul University, Izmir,Turkey
| | - Süha Miral
- Deparment of Child and Adolescent Psychiatry, Dokuz Eylul University, Izmir, Turkey
| | - Hatice Durak
- Deparment of Nuclear Medicine, Dokuz Eylul University, Izmir, Turkey
| | | | - Luis Augusto Rohde
- Department of Psychiatry, Federal University of Rio Grande do Sul, Brazil; ADHD Program, Hospital de Clínicas de Porto Alegre, Brazil
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Klein M, Onnink M, van Donkelaar M, Wolfers T, Harich B, Shi Y, Dammers J, Arias-Vásquez A, Hoogman M, Franke B. Brain imaging genetics in ADHD and beyond - Mapping pathways from gene to disorder at different levels of complexity. Neurosci Biobehav Rev 2017; 80:115-155. [PMID: 28159610 PMCID: PMC6947924 DOI: 10.1016/j.neubiorev.2017.01.013] [Citation(s) in RCA: 58] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2016] [Revised: 12/08/2016] [Accepted: 01/09/2017] [Indexed: 01/03/2023]
Abstract
Attention-deficit/hyperactivity disorder (ADHD) is a common and often persistent neurodevelopmental disorder. Beyond gene-finding, neurobiological parameters, such as brain structure, connectivity, and function, have been used to link genetic variation to ADHD symptomatology. We performed a systematic review of brain imaging genetics studies involving 62 ADHD candidate genes in childhood and adult ADHD cohorts. Fifty-one eligible research articles described studies of 13 ADHD candidate genes. Almost exclusively, single genetic variants were studied, mostly focussing on dopamine-related genes. While promising results have been reported, imaging genetics studies are thus far hampered by methodological differences in study design and analysis methodology, as well as limited sample sizes. Beyond reviewing imaging genetics studies, we also discuss the need for complementary approaches at multiple levels of biological complexity and emphasize the importance of combining and integrating findings across levels for a better understanding of biological pathways from gene to disease. These may include multi-modal imaging genetics studies, bioinformatic analyses, and functional analyses of cell and animal models.
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Affiliation(s)
- Marieke Klein
- Department of Human Genetics, Radboud university medical center, Donders Institute for Brain, Cognition and Behaviour, Nijmegen, The Netherlands
| | - Marten Onnink
- Department of Human Genetics, Radboud university medical center, Donders Institute for Brain, Cognition and Behaviour, Nijmegen, The Netherlands
| | - Marjolein van Donkelaar
- Department of Human Genetics, Radboud university medical center, Donders Institute for Brain, Cognition and Behaviour, Nijmegen, The Netherlands
| | - Thomas Wolfers
- Department of Human Genetics, Radboud university medical center, Donders Institute for Brain, Cognition and Behaviour, Nijmegen, The Netherlands
| | - Benjamin Harich
- Department of Human Genetics, Radboud university medical center, Donders Institute for Brain, Cognition and Behaviour, Nijmegen, The Netherlands
| | - Yan Shi
- Department of Human Genetics, Radboud university medical center, Donders Institute for Brain, Cognition and Behaviour, Nijmegen, The Netherlands
| | - Janneke Dammers
- Department of Human Genetics, Radboud university medical center, Donders Institute for Brain, Cognition and Behaviour, Nijmegen, The Netherlands; Department of Psychiatry, Radboud university medical center, Donders Institute for Brain, Cognition and Behaviour, Nijmegen, The Netherlands
| | - Alejandro Arias-Vásquez
- Department of Human Genetics, Radboud university medical center, Donders Institute for Brain, Cognition and Behaviour, Nijmegen, The Netherlands; Department of Psychiatry, Radboud university medical center, Donders Institute for Brain, Cognition and Behaviour, Nijmegen, The Netherlands; Department of Cognitive Neuroscience, Radboud university medical center, Donders Institute for Brain, Cognition and Behaviour, Nijmegen, The Netherlands
| | - Martine Hoogman
- Department of Human Genetics, Radboud university medical center, Donders Institute for Brain, Cognition and Behaviour, Nijmegen, The Netherlands
| | - Barbara Franke
- Department of Human Genetics, Radboud university medical center, Donders Institute for Brain, Cognition and Behaviour, Nijmegen, The Netherlands; Department of Psychiatry, Radboud university medical center, Donders Institute for Brain, Cognition and Behaviour, Nijmegen, The Netherlands.
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Chung T, Ferrell R, Clark DB. Indirect association of DAT1 genotype with executive function through white matter volume in orbitofrontal cortex. Psychiatry Res 2015; 232:76-83. [PMID: 25704259 PMCID: PMC4404197 DOI: 10.1016/j.pscychresns.2015.01.021] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/30/2014] [Revised: 09/03/2014] [Accepted: 01/26/2015] [Indexed: 01/14/2023]
Abstract
The dopamine transporter (DAT1) gene has been associated with impulsivity and executive functioning. Further, DAT1 has been associated with brain structural characteristics and resting state connectivity. This study tested an indirect effect model in which DAT1 genotype (9-repeat (9R) carriers vs 10-repeat (10R) homozygotes) is linked to phenotypes representing impulsivity and executive function (planning behavior) through effects on white matter (WM) volumes in prefrontal cortex (PFC), particularly orbitofrontal cortex (OFC). Adolescents (ages 14-18, n=38) were recruited from substance use treatment (n=22) and the community (n=16) to increase phenotype variation. Results indicated that DAT1 10/10 genotype was associated with lower WM volume in the PFC, specifically the left OFC. Further, lower WM volume in the left OFC predicted more difficulties in self-reported planning behavior, but not impulsivity. Indirect effect analysis indicated that lower WM volume in the left OFC mediated the association between DAT1 10/10 genotype and difficulties in planning behavior. Results suggest a brain structural mechanism, involving lower WM volume in the left OFC, as a link in the association between DAT1 genotype and a specific aspect of executive function. Genetic effects on regional WM volume that are linked to behavioral outcomes could ultimately inform the development of tailored interventions that address an individual׳s unique risk factors.
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Affiliation(s)
- Tammy Chung
- Western Psychiatric Institute and Clinic, University of Pittsburgh Medical Center, Pittsburgh, PA, USA.
| | - Robert Ferrell
- Department of Human Genetics, University of Pittsburgh Pittsburgh, Pennsylvania, USA
| | - Duncan B. Clark
- Western Psychiatric Institute and Clinic, University of Pittsburgh Medical Center Pittsburgh, Pennsylvania, USA
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Functional effects of dopamine transporter gene genotypes on in vivo dopamine transporter functioning: a meta-analysis. Mol Psychiatry 2014; 19:880-9. [PMID: 24061496 DOI: 10.1038/mp.2013.126] [Citation(s) in RCA: 96] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/20/2013] [Revised: 08/15/2013] [Accepted: 08/16/2013] [Indexed: 12/20/2022]
Abstract
Much psychiatric genetic research has focused on a 40-base pair variable number of tandem repeats (VNTR) polymorphism located in the 3'-untranslated region (3'UTR) of the dopamine active transporter (DAT) gene (SLC6A3). This variant produces two common alleles with 9- and 10-repeats (9R and 10R). Studies associating this variant with in vivo DAT activity in humans have had mixed results. We searched for studies using positron emission tomography (PET) or single-photon emission computed tomography (SPECT) to evaluate this association. Random effects meta-analyses assessed the association of the 3'UTR variant with DAT activity. We also evaluated heterogeneity among studies and evidence for publication bias. We found twelve studies comprising 511 subjects, 125 from PET studies and 386 from SPECT studies. The PET studies provided highly significant evidence that the 9R allele was associated with increased DAT activity in human adults. The SPECT studies were highly heterogeneous. As a group, they suggested no association between the 3'UTR polymorphism and DAT activity. When the analysis was limited to the most commonly used ligand, [123I]β-CIT, stratification by affection status dramatically reduced heterogeneity and revealed a significant association of the 9R allele with increased DAT activity for healthy subjects. In humans, the 9R allele of the 3'UTR polymorphism of SLC6A3 regulates dopamine activity in the striatal brain regions independent of the presence of neuropsychiatric illness. Differences in study methodology account for the heterogeneous results across individual studies.
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Valomon A, Holst SC, Bachmann V, Viola AU, Schmidt C, Zürcher J, Berger W, Cajochen C, Landolt HP. Genetic polymorphisms of DAT1 and COMT differentially associate with actigraphy-derived sleep-wake cycles in young adults. Chronobiol Int 2014; 31:705-14. [PMID: 24625311 DOI: 10.3109/07420528.2014.896376] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Accumulating evidence suggests that dopamine plays a key role in sleep-wake regulation. Cerebral dopamine levels are regulated primarily by the dopamine transporter (DAT) in the striatum and by catechol-O-methyl-transferase (COMT) in the prefrontal cortex. We hypothesized that the variable-number-tandem-repeat (VNTR) polymorphism in the 3'-untranslated region of the gene encoding DAT (DAT1, SLC6A3; rs28363170) and the Val158Met polymorphism of COMT (rs4680) differently affect actigraphy-derived rest-activity cycles and sleep estimates in healthy adults (65 men; 45 women; age range: 19-35 years). Daytime sleepiness, continuous rest-actigraphy and sleep diary data during roughly 4-weeks were analyzed. Nine-repeat (9R) allele carriers of DAT1 (n = 48) more often reported elevated sleepiness (Epworth sleepiness score ≥10) than 10-repeat (10R) allele homozygotes (n = 62, p < 0.02). Moreover, male 9R allele carriers showed higher wrist activity, whereas this difference was not present in women ("DAT1 genotype" × "gender" interaction: p < 0.005). Rest-activity patterns did not differ among COMT genotypes. Nevertheless, a significant "COMT genotype" × "type of day" (workdays vs. rest days) interaction for sleep duration was observed (p = 0.04). The Val/Val (n = 36) and Met/Met (n = 24) homozygotes habitually prolonged sleep on rest days compared to workdays by more than 30 min, while Val/Met heterozygotes (n = 50) did not significantly extend their sleep (mean difference: 7 min). Moreover, whereas the proportion of women among the genotype groups did not differ, COMT genotype affected body-mass-index (BMI), such that Val/Met individuals had lower BMI than the homozygous genotypes (p < 0.04). While awaiting independent replication and confirmation, our data support an association of genetically-determined differences in cerebral dopaminergic neurotransmission with daytime sleepiness and individual rest-activity profiles, as well as other sleep-associated health characteristics such as the regulation of BMI. The differential associations of DAT1 and COMT polymorphisms may reflect the distinct local expression of the encoded proteins in the brain.
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Affiliation(s)
- Amandine Valomon
- Institute of Pharmacology and Toxicology, University of Zürich , Zürich , Switzerland
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Gordon EM, Devaney JM, Bean S, Vaidya CJ. Resting-state striato-frontal functional connectivity is sensitive to DAT1 genotype and predicts executive function. ACTA ACUST UNITED AC 2013; 25:336-45. [PMID: 23968837 DOI: 10.1093/cercor/bht229] [Citation(s) in RCA: 50] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Individual differences in striatal dopamine (DA) signaling have been associated both with individual differences in executive function in healthy individuals and with risk for psychiatric disorders defined by executive dysfunction. We used resting-state functional connectivity in 50 healthy adults to examine whether a polymorphism of the dopamine transporter gene (DAT1), which regulates striatal DA function, affects striatal functional connectivity in healthy adults, and whether that connectivity predicts executive function. We found that 9/10 heterozygotes, who are believed to have higher striatal DA signaling, demonstrated stronger connectivity between dorsal caudate (DC) and insular, dorsal anterior cingulate, and dorsolateral prefrontal regions, as well as between ventral striatum and ventrolateral prefrontal cortex, than 10/10 homozygotes. Across subjects, stronger DC-seeded connectivity predicted superior N-back working memory performance, while stronger ventral striatum-seeded connectivity predicted reduced impulsivity in everyday life. Further, mediation analysis suggested that connectivity strength mediated relationships between DAT1 genotype and behavior. These findings suggest that resting-state striato-frontal connectivity may be an endophenotype for executive function in healthy individuals.
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Affiliation(s)
- Evan M Gordon
- Interdisciplinary Program in Neuroscience, Georgetown University Medical Center, Washington, DC 20007, USA
| | - Joseph M Devaney
- Department of Integrative Systems Biology, Research Center for Genetic Medicine, Children's National Medical Center, Washington, DC 20310, USA
| | - Stephanie Bean
- Department of Psychology, Georgetown University, Washington, DC 20057, USA and
| | - Chandan J Vaidya
- Department of Psychology, Georgetown University, Washington, DC 20057, USA and Children's Research Institute, Children's National Medical Center, Washington, DC 20310, USA
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Spencer TJ, Biederman J, Faraone SV, Madras BK, Bonab AA, Dougherty DD, Batchelder H, Clarke A, Fischman AJ. Functional genomics of attention-deficit/hyperactivity disorder (ADHD) risk alleles on dopamine transporter binding in ADHD and healthy control subjects. Biol Psychiatry 2013; 74:84-9. [PMID: 23273726 PMCID: PMC3700607 DOI: 10.1016/j.biopsych.2012.11.010] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/23/2012] [Revised: 11/11/2012] [Accepted: 11/13/2012] [Indexed: 11/28/2022]
Abstract
BACKGROUND The main aim of this study was to examine the relationship between dopamine transporter (DAT) binding in the striatum in individuals with and without attention-deficit/hyperactivity disorder (ADHD), attending to the 3'-untranslated region of the gene (3'-UTR) and intron8 variable number of tandem repeats (VNTR) polymorphisms of the DAT (SLC6A3) gene. METHODS Subjects consisted of 68 psychotropic (including stimulant)-naïve and smoking-naïve volunteers between 18 and 55 years of age (ADHD n = 34; control subjects n = 34). Striatal DAT binding was measured with positron emission tomography with 11C altropane. Genotyping of the two DAT (SLC6A3) 3'-UTR and intron8 VNTRs used standard protocols. RESULTS The gene frequencies of each of the gene polymorphisms assessed did not differ between the ADHD and control groups. The ADHD status (t = 2.99; p<.004) and 3'-UTR of SLC6A3 9 repeat carrier status (t = 2.74; p<.008) were independently and additively associated with increased DAT binding in the caudate. The ADHD status was associated with increased striatal (caudate) DAT binding regardless of 3'-UTR genotype, and 3'-UTR genotype was associated with increased striatal (caudate) DAT binding regardless of ADHD status. In contrast, there were no significant associations between polymorphisms of DAT intron8 or the 3'-UTR-intron8 haplotype with DAT binding. CONCLUSIONS The 3'-UTR but not intron8 VNTR genotypes were associated with increased DAT binding in both ADHD patients and healthy control subjects. Both ADHD status and the 3'-UTR polymorphism status had an additive effect on DAT binding. Our findings suggest that an ADHD risk polymorphism (3'-UTR) of SLC6A3 has functional consequences on central nervous system DAT binding in humans.
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Affiliation(s)
- Thomas J Spencer
- Pediatric Psychopharmacology Unit, Boston, Massachusetts 02114, USA.
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Fayed N, Lopez del Hoyo Y, Andres E, Serrano-Blanco A, Bellón J, Aguilar K, Cebolla A, Garcia-Campayo J. Brain changes in long-term zen meditators using proton magnetic resonance spectroscopy and diffusion tensor imaging: a controlled study. PLoS One 2013; 8:e58476. [PMID: 23536796 PMCID: PMC3607604 DOI: 10.1371/journal.pone.0058476] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2012] [Accepted: 02/05/2013] [Indexed: 11/19/2022] Open
Abstract
Introduction This work aimed to determine whether 1H magnetic resonance imaging (MRI), magnetic resonance spectroscopy (MRS), diffusion-weighted imaging (DWI) and diffusion tensor imaging (DTI) are correlated with years of meditation and psychological variables in long-term Zen meditators compared to healthy non-meditator controls. Materials and Methods Design. Controlled, cross-sectional study. Sample. Meditators were recruited from a Zen Buddhist monastery. The control group was recruited from hospital staff. Meditators were administered questionnaires on anxiety, depression, cognitive impairment and mindfulness. 1H-MRS (1.5 T) of the brain was carried out by exploring four areas: both thalami, both hippocampi, the posterior superior parietal lobule (PSPL) and posterior cingulate gyrus. Predefined areas of the brain were measured for diffusivity (ADC) and fractional anisotropy (FA) by MR-DTI. Results Myo-inositol (mI) was increased in the posterior cingulate gyrus and Glutamate (Glu), N-acetyl-aspartate (NAA) and N-acetyl-aspartate/Creatine (NAA/Cr) was reduced in the left thalamus in meditators. We found a significant positive correlation between mI in the posterior cingulate and years of meditation (r = 0.518; p = .019). We also found significant negative correlations between Glu (r = −0.452; p = .045), NAA (r = −0.617; p = .003) and NAA/Cr (r = −0.448; P = .047) in the left thalamus and years of meditation. Meditators showed a lower Apparent Diffusion Coefficient (ADC) in the left posterior parietal white matter than did controls, and the ADC was negatively correlated with years of meditation (r = −0.4850, p = .0066). Conclusions The results are consistent with the view that mI, Glu and NAA are the most important altered metabolites. This study provides evidence of subtle abnormalities in neuronal function in regions of the white matter in meditators.
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Affiliation(s)
- Nicolás Fayed
- Department of Radiology, Hospital Quirón, Zaragoza, Spain
| | | | - Eva Andres
- CIBER Epidemiología y Salud Pública, Unidad Epidemiología Clínica, Hospital 12 de Octubre, Madrid, Spain
| | - Antoni Serrano-Blanco
- Parc Sanitari Sant Joan de Déu & Fundació Sant Joan de Déu. Sant Boi de Llobregat, Barcelona, Spain
| | - Juan Bellón
- Centro de Salud El Palo, Unidad de Investigación del Distrito de Atención Primaria de Málaga (redIAPP, grupo SAMSERAP), Departamento de Medicina Preventiva, Universidad de Málaga, Málaga, Spain
| | - Keyla Aguilar
- Department of Radiology, Hospital Quirón, Zaragoza, Spain
| | - Ausias Cebolla
- CIBER de Fisiopatología de la Obesidad y Nutrición (CIBEROBN), Universidad Jaime I, Castellón, Spain
| | - Javier Garcia-Campayo
- Servicio de Psiquiatría, Hospital Miguel Servet y Universidad de Zaragoza, Instituto Aragonés de Ciencias de la Salud, Zaragoza, Spain
- * E-mail:
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12
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Gordon EM, Stollstorff M, Devaney JM, Bean S, Vaidya CJ. Effect of dopamine transporter genotype on intrinsic functional connectivity depends on cognitive state. ACTA ACUST UNITED AC 2011; 22:2182-96. [PMID: 22047966 DOI: 10.1093/cercor/bhr305] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Functional connectivity between brain regions can define large-scale neural networks and provide information about relationships between those networks. We examined how relationships within and across intrinsic connectivity networks were 1) sensitive to individual differences in dopaminergic function, 2) modulated by cognitive state, and 3) associated with executive behavioral traits. We found that regardless of cognitive state, connections between frontal, parietal, and striatal nodes of Task-Positive networks (TPNs) and Task-Negative networks (TNNs) showed higher functional connectivity in 10/10 homozygotes of the dopamine transporter gene, a polymorphism influencing synaptic dopamine, than in 9/10 heterozygotes. However, performance of a working memory task (a state requiring dopamine release) modulated genotype differences selectively, such that cross-network connectivity between TPNs and TNNs was higher in 10/10 than 9/10 subjects during working memory but not during rest. This increased cross-network connectivity was associated with increased self-reported measures of impulsivity and inattention traits. By linking a gene regulating synaptic dopamine to a phenotype characterized by inefficient executive function, these findings validate cross-network connectivity as an endophenotype of executive dysfunction.
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Affiliation(s)
- Evan M Gordon
- Interdisciplinary Program in Neuroscience, Georgetown University Medical Center, Washington, DC 20057, USA
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13
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Felten A, Montag C, Markett S, Walter NT, Reuter M. Genetically determined dopamine availability predicts disposition for depression. Brain Behav 2011; 1:109-18. [PMID: 22399090 PMCID: PMC3236544 DOI: 10.1002/brb3.20] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/16/2011] [Revised: 07/29/2011] [Accepted: 08/31/2011] [Indexed: 12/29/2022] Open
Abstract
Although prominent personality theories postulate orthogonality between traits of positive emotionality (PEM) and negative emotionality (NEM), empirical evidence often demonstrates the opposite indicating a negative relationship. Therefore, it is not surprising that dopaminergic (DA) gene loci have been related to traits of positive and of NEM. The present genetic association study investigates the influence of two functional DA gene polymorphisms on Sadness as defined by the Affective Neuroscience Personality Scales (ANPS) in healthy Caucasians (n = 1041). We observed a significant interaction effect between the 10-repeat (10R) allele of the dopamine transporter (DAT1) gene and the methionine (Met) allele of the catechol-O-methyltransferase (COMT) Val158Met polymorphism (F((1,1018)) = 11.11; P < 0.001). Carriers of the 9R/9R and the Val/Val genotype showed dramatically reduced Sadness scores in comparison to the other three genotype configurations. Both the 9R/9R and the Val/Val genotypes characterized by reduced transporter density and high dopamine catabolism, respectively, have been separately related to personality traits of PEM and externalizing behavior in the past. The present findings indicate that gene variations of the DA system previously associated with PEM are at the same time protective against high NEM and can therefore constitute a resilience factor against depression.
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Affiliation(s)
- Andrea Felten
- Department of Psychology, University of Bonn, Bonn, Germany
- Laboratory of Neurogenetics, University of Bonn, Bonn, Germany
- Center for Economics & Neuroscience, University of Bonn, Germany
| | - Christian Montag
- Department of Psychology, University of Bonn, Bonn, Germany
- Laboratory of Neurogenetics, University of Bonn, Bonn, Germany
| | - Sebastian Markett
- Department of Psychology, University of Bonn, Bonn, Germany
- Laboratory of Neurogenetics, University of Bonn, Bonn, Germany
| | - Nora T. Walter
- Department of Psychology, University of Bonn, Bonn, Germany
- Laboratory of Neurogenetics, University of Bonn, Bonn, Germany
| | - Martin Reuter
- Department of Psychology, University of Bonn, Bonn, Germany
- Laboratory of Neurogenetics, University of Bonn, Bonn, Germany
- Center for Economics & Neuroscience, University of Bonn, Germany
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14
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The roles of dopamine and noradrenaline in the pathophysiology and treatment of attention-deficit/hyperactivity disorder. Biol Psychiatry 2011; 69:e145-57. [PMID: 21550021 DOI: 10.1016/j.biopsych.2011.02.036] [Citation(s) in RCA: 395] [Impact Index Per Article: 30.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/11/2010] [Revised: 01/16/2011] [Accepted: 02/15/2011] [Indexed: 12/14/2022]
Abstract
Through neuromodulatory influences over fronto-striato-cerebellar circuits, dopamine and noradrenaline play important roles in high-level executive functions often reported to be impaired in attention-deficit/hyperactivity disorder (ADHD). Medications used in the treatment of ADHD (including methylphenidate, dextroamphetamine and atomoxetine) act to increase brain catecholamine levels. However, the precise prefrontal cortical and subcortical mechanisms by which these agents exert their therapeutic effects remain to be fully specified. Herein, we review and discuss the present state of knowledge regarding the roles of dopamine (DA) and noradrenaline in the regulation of corticostriatal circuits, with a focus on the molecular neuroimaging literature (both in ADHD patients and in healthy subjects). Recent positron emission tomography evidence has highlighted the utility of quantifying DA markers, at baseline or following drug administration, in striatal subregions governed by differential cortical connectivity. This approach opens the possibility of characterizing the neurobiological underpinnings of ADHD (and associated cognitive dysfunction) and its treatment by targeting specific neural circuits. It is anticipated that the application of refined and novel positron emission tomography methodology will help to disentangle the overlapping and dissociable contributions of DA and noradrenaline in the prefrontal cortex, thereby aiding our understanding of ADHD and facilitating new treatments.
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15
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Costa A, Riedel M, Müller U, Möller HJ, Ettinger U. Relationship between SLC6A3 genotype and striatal dopamine transporter availability: a meta-analysis of human single photon emission computed tomography studies. Synapse 2011; 65:998-1005. [PMID: 21404331 DOI: 10.1002/syn.20927] [Citation(s) in RCA: 65] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2011] [Accepted: 02/14/2011] [Indexed: 11/06/2022]
Abstract
The human dopamine transporter (DAT) gene (SLC6A3) contains a 40-bp variable number of tandem repeats (VNTR) polymorphism. A number of studies have investigated the association of this VNTR with striatal DAT availability in humans using single photon emission computed tomography (SPECT). However, the results are not consistent. Therefore, we carried out a meta-analysis of the association between the SLC6A3 VNTR and striatal DAT binding measured in human SPECT studies. The meta-analysis of five samples of healthy individuals failed to find a significant difference in DAT availability between SLC6A3 9-repeat carriers and 10-repeat homozygotes (P = 0.22) although the 9R carriers had nominally higher striatal DAT levels (g = 0.66). The results remained nonsignificant after the inclusion of patient samples, namely schizophrenia, attention deficit hyperactivity disorder, and Parkinson's disease (four samples; all P > 0.18). To conclude, this meta-analysis provides no evidence to support the hypothesis that the SLC6A3 VNTR is significantly associated with interindividual differences in DAT availability in the human striatum. Further work is needed to clarify the molecular mechanisms by which this polymorphism may affect cognition and psychiatric disorders, if not through altered expression as measured by molecular imaging.
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Affiliation(s)
- Anna Costa
- Department of Psychiatry, Ludwig-Maximilians-University, Munich, Germany.
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16
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Shook D, Brady C, Lee PS, Kenealy L, Murphy ER, Gaillard WD, VanMeter JW, Cook EH, Stein M, Vaidya CJ. Effect of dopamine transporter genotype on caudate volume in childhood ADHD and controls. Am J Med Genet B Neuropsychiatr Genet 2011; 156B:28-35. [PMID: 20957668 PMCID: PMC3010298 DOI: 10.1002/ajmg.b.31132] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/22/2010] [Accepted: 09/02/2010] [Indexed: 12/30/2022]
Abstract
Polymorphism of the dopamine transporter genotype (DAT1) confers a small but significant susceptibility to attention deficit hyperactivity disorder (ADHD). We examined whether the volume of the head of caudate, a striatal structure with high DAT expression that is important for inhibitory function, differs by DAT1 in children diagnosed with the disorder relative to age and IQ matched controls. Volume of the head of caudate was delineated in the right and left hemisphere and compared between 7- and 13-year-old children with and without ADHD (combined type) who were carriers of two (10/10) or one (9/10) copy of the 10-repeat DAT1 allele. Caudate volumes were overall smaller in 10/10 than 9/10 children, particularly in the left than right hemisphere. While DAT1 effects did not vary by ADHD diagnosis, overall caudate volumes were smaller in ADHD relative to control children. Altered caudate development associated with 10-repeat homozygosity of DAT1 may contribute susceptibility to ADHD.
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Affiliation(s)
- Devon Shook
- Department of Psychology, Georgetown University, Washington DC
| | - Colin Brady
- Department of Psychology, Georgetown University, Washington DC
| | - Philip S. Lee
- Department of Psychology, Georgetown University, Washington DC
| | - Laura Kenealy
- Center for Neuroscience, Children’s National Medical Center, Washington, DC
| | - Eric R. Murphy
- Department of Psychology, Georgetown University, Washington DC
| | | | - John W. VanMeter
- Center for Functional and Molecular Imaging, Georgetown University Medical Center, Washington, DC
| | - Edwin H. Cook
- Department of Psychiatry, University of Illinois at Chicago, Chicago, IL
| | - Mark Stein
- Department of Psychiatry, University of Illinois at Chicago, Chicago, IL
| | - Chandan J. Vaidya
- Department of Psychology, Georgetown University, Washington DC, Center for Neuroscience, Children’s National Medical Center, Washington, DC
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17
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Durston S. Imaging genetics in ADHD. Neuroimage 2010; 53:832-8. [DOI: 10.1016/j.neuroimage.2010.02.071] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2009] [Revised: 02/23/2010] [Accepted: 02/25/2010] [Indexed: 01/10/2023] Open
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Simon JR, Stollstorff M, Westbay LC, Vaidya CJ, Howard JH, Howard DV. Dopamine transporter genotype predicts implicit sequence learning. Behav Brain Res 2010; 216:452-7. [PMID: 20817043 DOI: 10.1016/j.bbr.2010.08.043] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2010] [Revised: 08/25/2010] [Accepted: 08/26/2010] [Indexed: 11/30/2022]
Abstract
Implicit learning, the non-conscious acquisition of sequential and spatial environmental regularities, underlies skills such as language, social intuition, or detecting a target in a complex scene. We examined relationships between a variation of the dopamine transporter (DAT1) gene (SLC6A3), which influences dopamine transporter expression in the striatum, and two forms of implicit learning that differ in the regularity to be learned and in striatal involvement. Participants, grouped as 9-repeat carriers or 10/10 homozygotes, completed the triplets learning task (TLT) and the spatial contextual cueing task (SCCT). The TLT assesses sequence learning, recruiting the striatal system, particularly as training continues. In contrast, the SCCT assesses spatial context learning, recruiting medial temporal brain networks. For both tasks, participants demonstrated learning in faster and/or more accurate responses to repeating patterns or spatial arrays. As predicted, TLT learning was greater for the 9-repeat carriers than the 10/10 group (despite equal overall accuracy and response speed) whereas there were no significant group differences in SCCT. Thus, presence of the DAT1 9-repeat allele was beneficial only for implicit sequence learning, indicating the influence of DAT1 genotype on one form of implicit learning and supporting evidence that implicit learning of sequential dependencies and spatial layouts recruit different neural systems.
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Affiliation(s)
- Jessica R Simon
- Department of Psychology, Georgetown University, Washington, DC 20057, United States.
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19
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Kooij SJJ, Bejerot S, Blackwell A, Caci H, Casas-Brugué M, Carpentier PJ, Edvinsson D, Fayyad J, Foeken K, Fitzgerald M, Gaillac V, Ginsberg Y, Henry C, Krause J, Lensing MB, Manor I, Niederhofer H, Nunes-Filipe C, Ohlmeier MD, Oswald P, Pallanti S, Pehlivanidis A, Ramos-Quiroga JA, Rastam M, Ryffel-Rawak D, Stes S, Asherson P. European consensus statement on diagnosis and treatment of adult ADHD: The European Network Adult ADHD. BMC Psychiatry 2010; 10:67. [PMID: 20815868 PMCID: PMC2942810 DOI: 10.1186/1471-244x-10-67] [Citation(s) in RCA: 499] [Impact Index Per Article: 35.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/04/2010] [Accepted: 09/03/2010] [Indexed: 12/26/2022] Open
Abstract
BACKGROUND Attention deficit hyperactivity disorder (ADHD) is among the most common psychiatric disorders of childhood that persists into adulthood in the majority of cases. The evidence on persistence poses several difficulties for adult psychiatry considering the lack of expertise for diagnostic assessment, limited treatment options and patient facilities across Europe. METHODS The European Network Adult ADHD, founded in 2003, aims to increase awareness of this disorder and improve knowledge and patient care for adults with ADHD across Europe. This Consensus Statement is one of the actions taken by the European Network Adult ADHD in order to support the clinician with research evidence and clinical experience from 18 European countries in which ADHD in adults is recognised and treated. RESULTS Besides information on the genetics and neurobiology of ADHD, three major questions are addressed in this statement: (1) What is the clinical picture of ADHD in adults? (2) How can ADHD in adults be properly diagnosed? (3) How should ADHD in adults be effectively treated? CONCLUSIONS ADHD often presents as an impairing lifelong condition in adults, yet it is currently underdiagnosed and treated in many European countries, leading to ineffective treatment and higher costs of illness. Expertise in diagnostic assessment and treatment of ADHD in adults must increase in psychiatry. Instruments for screening and diagnosis of ADHD in adults are available and appropriate treatments exist, although more research is needed in this age group.
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Affiliation(s)
- Sandra JJ Kooij
- PsyQ, psycho medische programma's, Department Adult ADHD, Carel Reinierszkade 197, Den Haag, The Netherlands
| | - Susanne Bejerot
- Department of Clinical Neuroscience, Karolinksa Institutet, Section Psychiatry, St. Goran, Stockholm, Sweden
| | - Andrew Blackwell
- University Department of Psychiatry, Addenbrookes Hospital, Cambridge, UK
| | - Herve Caci
- Pediatric Department, Hôpitaux Pédiatriques CHU-Lenval, 06200 Nice, France
| | - Miquel Casas-Brugué
- Servicio de Psiquiatria, Hospital Universitari Vall d' Hebron, Universidad Autonoma de Barcelona, Barcelona, Spain
| | - Pieter J Carpentier
- Reinier van Arkel Groep, Postbus 70058, 5201 DZ 's-Hertogenbosch, The Netherlands
| | - Dan Edvinsson
- Department of Neuroscience/Psychiatri Ulleråker, MK 75, S-750 17 Uppsala, Sweden
| | - John Fayyad
- Institute of Development, Research, Advocacy and Applied Care (IDRAAC), Department of Psychiatry and Clinical Psychology, St George Hospital University Medical Centre, Balamand University, Beirut, Lebanon
| | - Karin Foeken
- Centre des Consultations, Institut A Tzanck, Mougins, France
| | - Michael Fitzgerald
- Department of Psychiatry, Trinity College Dublin (TCD), Dublin 2, Ireland
| | - Veronique Gaillac
- Clinique des Maladies Mentales et de l'Encéphale (CMME), Sainte Anne Hospital Paris, France
| | - Ylva Ginsberg
- Affektiva mottagningen, M 59, Psykiatri Sydväst, 141 86 Stockholm, Sweden
| | - Chantal Henry
- Département de Psychiatrie Adulte, Unité Lescure, CH Charles Perrens, Bordeaux, France
| | - Johanna Krause
- Private clinic for psychiatry and psychotherapy, 11a Schillerstrasse, Ottobrunn, Germany
| | - Michael B Lensing
- Department of Child Neurology, Oslo University Hospital, Ullevaal, Oslo, Norway
| | - Iris Manor
- Geha Mental Health Center, Petach-Tiqva, Sackler Faculty of Medicine, Tel-Aviv University, Israel
| | - Helmut Niederhofer
- Department of Child Psychiatry, Regional Hospital of Bolzano, Via Guncina, Bolzano, Italy
| | - Carlos Nunes-Filipe
- Faculty of Medical Sciences, New University of Lisbon, Campo dos Mártires da Pátria, 1169-056 Lisboa, Portugal
| | - Martin D Ohlmeier
- Department of Psychiatry, Social Psychiatry and Psychotherapy, Hannover Medical School, Germany
| | - Pierre Oswald
- Department of Psychiatry, Brugmann University Hospital, Université Libre de Bruxelles, Brussels, Belgium
| | - Stefano Pallanti
- Department of Neurosciences, Florence University, Florence, Italy
| | - Artemios Pehlivanidis
- Department of Psychiatry, National and Kapodistrian University of Athens Medical School, Eginition Hospital, Athens, Greece
| | - Josep A Ramos-Quiroga
- Programa Integral del Déficit de Atención en el Adulto (P.I.D.A.A), Servei de Psiquiatria, Hospital Universitari Vall d'Hebron, Barcelona, Spain
| | - Maria Rastam
- Department of Clinical Sciences, Lund, Child and Adolescent Psychiatry, Lund University, Sweden
| | | | - Steven Stes
- ADHD Program, University Psychiatric Center, Catholic University Leuven, Kortenberg, Belgium
| | - Philip Asherson
- MRC Social Genetic and Developmental Psychiatry, Institute of Psychiatry, Kings College London, London, UK
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Shumay E, Fowler JS, Volkow ND. Genomic features of the human dopamine transporter gene and its potential epigenetic States: implications for phenotypic diversity. PLoS One 2010; 5:e11067. [PMID: 20548783 PMCID: PMC2883569 DOI: 10.1371/journal.pone.0011067] [Citation(s) in RCA: 58] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2010] [Accepted: 05/18/2010] [Indexed: 02/06/2023] Open
Abstract
Human dopamine transporter gene (DAT1 or SLC6A3) has been associated with various brain-related diseases and behavioral traits and, as such, has been investigated intensely in experimental- and clinical-settings. However, the abundance of research data has not clarified the biological mechanism of DAT regulation; similarly, studies of DAT genotype-phenotype associations yielded inconsistent results. Hence, our understanding of the control of the DAT protein product is incomplete; having this knowledge is critical, since DAT plays the major role in the brain's dopaminergic circuitry. Accordingly, we reevaluated the genomic attributes of the SLC6A3 gene that might confer sensitivity to regulation, hypothesizing that its unique genomic characteristics might facilitate highly dynamic, region-specific DAT expression, so enabling multiple regulatory modes. Our comprehensive bioinformatic analyzes revealed very distinctive genomic characteristics of the SLC6A3, including high inter-individual variability of its sequence (897 SNPs, about 90 repeats and several CNVs spell out all abbreviations in abstract) and pronounced sensitivity to regulation by epigenetic mechanisms, as evident from the GC-bias composition (0.55) of the SLC6A3, and numerous intragenic CpG islands (27 CGIs). We propose that this unique combination of the genomic features and the regulatory attributes enables the differential expression of the DAT1 gene and fulfills seemingly contradictory demands to its regulation; that is, robustness of region-specific expression and functional dynamics.
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Affiliation(s)
- Elena Shumay
- Brookhaven National Laboratory, Medical Department, Upton, New York, United States of America
- * E-mail: (ES); (JSF); (NDV)
| | - Joanna S. Fowler
- Brookhaven National Laboratory, Medical Department, Upton, New York, United States of America
- * E-mail: (ES); (JSF); (NDV)
| | - Nora D. Volkow
- National Institute on Drug Abuse, National Institutes of Health, Bethesda, Maryland, United States of America
- * E-mail: (ES); (JSF); (NDV)
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21
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Dopamine and binge eating behaviors. Pharmacol Biochem Behav 2010; 97:25-33. [PMID: 20417658 DOI: 10.1016/j.pbb.2010.04.016] [Citation(s) in RCA: 102] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/30/2009] [Revised: 03/23/2010] [Accepted: 04/19/2010] [Indexed: 01/15/2023]
Abstract
Central dopaminergic mechanisms are involved in the motivational aspects of eating and food choices. This review focuses on human and animal data investigating the importance of dopamine on binge eating behaviors. Early work examining dopamine metabolites in the cerebrospinal fluid and plasma of bulimic individuals suggested decreased dopamine turnover during the active phase of the illness. While neuroimaging studies of dopamine mechanisms in bulimia nervosa (BN) and binge eating disorder (BED) are limited, genetic studies in humans have implicated an increased frequency of dopamine transporter and associated D2 receptor polymorphisms with binge pathology. Recent studies in rodent models of dietary-induced binge eating (DIBE) have investigated plausible dopamine mechanisms involved in sustaining binge eating behaviors. In DIBE models, highly palatable foods (fats, sugars and their combination), as well as restricted access conditions appear to promote ingestive responses and result in sustained dopamine stimulation within the nucleus accumbens. Taken together with studies on the comorbidity of illicit drug use and eating disorders, the data reviewed here support a role for dopamine in perpetuating the compulsive feeding patterns of BN and BED. As such, we propose that sustained stimulation of the dopamine systems by bingeing promoted by preexisting conditions (e.g., genetic traits, dietary restraint, stress, etc.) results in progressive impairments of dopamine signaling. To disrupt this vicious cycle, novel research-based treatment options aiming at the neural substrates of compulsive eating patterns are necessary.
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22
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Willeit M, Praschak-Rieder N. Imaging the effects of genetic polymorphisms on radioligand binding in the living human brain: A review on genetic neuroreceptor imaging of monoaminergic systems in psychiatry. Neuroimage 2010; 53:878-92. [PMID: 20399868 DOI: 10.1016/j.neuroimage.2010.04.030] [Citation(s) in RCA: 74] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2009] [Revised: 04/08/2010] [Accepted: 04/12/2010] [Indexed: 12/16/2022] Open
Abstract
Imaging genetics is a research field that describes the impact of genetic risk variants on brain structure and function. While magnetic resonance based imaging techniques are able to provide complex information on a system level, positron emission tomography (PET) and single photon emission computer tomography (SPECT) allow for determination of distribution and density of single receptor molecules in the human brain. Major psychiatric disorders are highly heritable, and have been associated with a dysregulation in brain dopamine and serotonin systems. Understanding the role of genetic polymorphisms within these neurotransmitter systems on brain phenotype is essential. This review tries to cover the literature on the impact of gene variants implicated in psychiatric disorders on serotonin, dopamine, and MAO-A radioligand binding in living humans. The majority of PET and SPECT studies investigated the role of polymorphisms within genes coding for the serotonin and dopamine transporters, the serotonin 1A receptor, and the dopamine D2 receptor on G protein coupled receptors or transporter proteins critically involved in serotonin or dopamine neurotransmission. Other studies investigated the impact of variants in genes for monoamine oxidase-A (MAO-A) or brain derived neurotrophic factor on monoamine transporters, receptors, or MAO-A activity. Two main findings in healthy subjects emerge from the current literature: one is an increased binding of the selective ligand [(11)C]DASB to serotonin transporters in subjects homozygous for the triallelic 5-HTTLPR LA allele. The other one is decreased binding of the radioligand [(11)C]raclopride to dopamine D2 receptors in D2 Taq1 A1 allele carriers. Other findings reported are highly interesting but require independent replication.
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Affiliation(s)
- Matthäus Willeit
- Division of Biological Psychiatry, Department of Psychiatry and Psychotherapy, Medical University of Vienna, Austria.
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Perlov E, Philipsen A, Matthies S, Drieling T, Maier S, Bubl E, Hesslinger B, Buechert M, Henning J, Ebert D, Tebartz Van Elst L. Spectroscopic findings in attention-deficit/hyperactivity disorder: review and meta-analysis. World J Biol Psychiatry 2010; 10:355-65. [PMID: 18609427 DOI: 10.1080/15622970802176032] [Citation(s) in RCA: 61] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
OBJECTIVES The last decade has seen an increasing interest in the method of magnet resonance spectroscopy (MRS) since this is the only research tool that allows a non-invasive in vivo assessment of neurochemical aspects of ADHD without employing ionising radiation. In this paper we review published MRS results with respect to childhood, adolescence and adult ADHD. METHOD We searched the Medline (Pub Med) database using the key words ADHD, attention-deficit/hyperactivity disorder, magnet resonance spectroscopy, MRS and spectroscopy. Citations of identified articles were also searched for relevant studies. Meta-analyses were performed for the measured metabolites and regions of assessment. RESULTS Sixteen studies could be identified that used MRS to investigate the neurobiology of ADHD. Two regions could be identified as the focus of spectroscopic investigations--the frontal lobe including anterior cingulate cortex and parts of prefrontal cortex and the basal ganglia, mostly striatum, alongside the fronto-striato-thalamo-frontal circuits. As for metabolites, in the majority of studies the ratios to creatine and not absolute concentrations of metabolites were estimated. Choline compounds, N-acetyl-aspartate and glutamate/glutamine (to creatine ratios) could be identified as being altered in several studies in ADHD. The meta-analysis showed increased choline compounds in several researched regions. DISCUSSION MRS is a promising tool for the non-invasive in vivo assessment of the cerebral neurochemistry in ADHD. More regions of interest (ROI) like amygdala, hippocampus, thalamus and cerebellum should be assessed in future studies. Further methodological improvements of MRS are desirable in order to assess the absolute metabolite concentration of several ROIs at the same time. Such developments will open novel perspectives in spectroscopic investigations of ADHD.
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Affiliation(s)
- Evgeniy Perlov
- Department of Psychiatry and Psychotherapy, University Hospital Freiburg, Freiburg, Germany.
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Scherk H, Backens M, Schneider-Axmann T, Kraft S, Kemmer C, Usher J, Reith W, Falkai P, Meyer J, Gruber O. Dopamine transporter genotype influences N-acetyl-aspartate in the left putamen. World J Biol Psychiatry 2010; 10:524-30. [PMID: 17965994 DOI: 10.1080/15622970701586349] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Abstract
INTRODUCTION Dopaminergic activity in the brain is modulated by the dopamine transporter (DAT). Several lines of evidence suggest that a variable number of tandem repeats (VNTR) polymorphism of the DAT1 gene (SLC6A3) influences its gene expression. The aim of this study was to determine whether the DAT1VNTR polymorphism alters the metabolic ratios NAA/Cho, NAA/Cr, Cho/Cr and Ins/Cr in the left dorsolateral prefrontal cortex, anterior cingulate cortex, and putamen in healthy subjects and psychiatric patients irrespective of clinical diagnosis. MATERIAL AND METHODS Sixty-four individuals (30 patients with bipolar disorder, 18 patients with obsessive-compulsive disorder, and 16 healthy subjects) participated in the study. The 3'-UTR VNTR polymorphism of DAT1 (SLC6A3) gene was genotyped in all individuals. (1)H-MRS was performed in the above-mentioned brain regions. RESULTS The individuals with the homozygous DAT1 10-repeat genotype presented significantly higher ratios of NAA/Cho and NAA/Cr in the left putamen compared to the group of individuals with the 9/9-repeat or 9/10-repeat genotype. CONCLUSION The VNTR polymorphism of the DAT1-gene modulates NAA/Cho and NAA/Cr in the left putamen independent of psychiatric diagnosis status. These results suggest an association of DAT1 VNTR polymorphism, dopaminergic activity, and neuronal function in putamen.
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Affiliation(s)
- Harald Scherk
- Department of Psychiatry and Psychotherapy, Georg-August-University Goettingen, Goettingen, Germany.
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Neural response to working memory load varies by dopamine transporter genotype in children. Neuroimage 2010; 53:970-7. [PMID: 20053379 DOI: 10.1016/j.neuroimage.2009.12.104] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2009] [Revised: 12/02/2009] [Accepted: 12/23/2009] [Indexed: 11/23/2022] Open
Abstract
Inheriting two (10/10) relative to one (9/10) copy of the 10-repeat allele of the dopamine transporter genotype (DAT1) is associated with Attention Deficit Hyperactivity Disorder, a childhood disorder marked by poor executive function. We examined whether functional anatomy underlying working memory, a component process of executive function, differed by DAT1 in 7-12 year-old typically developing children. 10/10 and 9/10 carriers performed a verbal n-back task in two functional magnetic resonance imaging (fMRI) runs varying in working memory load, high (2-back vs. 1-back) and low (1-back vs. 0-back). Performance accuracy was superior in 9/10 than 10/10 carriers in the high but not low load runs. Examination of each run separately revealed that frontal-striatal-parietal regions were more activated in 9/10 than 10/10 carriers in the high load run; the groups did not differ in the low load run. Examination of load effects revealed a DAT1xLoad interaction in the right hemisphere in the caudate, our a priori region of interest. Exploratory analysis at a more liberal threshold revealed this interaction in other basal ganglia regions (putamen, and substantial nigra/subthalamic nuclei - SN/STN) and in medial parietal cortex (left precuneus). The striatal and parietal regions were more activated in 9/10 carriers under high than low load, and DAT1 differences (9/10>10/10) were evident only under high load. In contrast, SN/STN tended to be more activated in 10/10 carriers under low than high load and DAT1 differences (10/10>9/10) were evident only under low load. Thus, 10-repeat homozygosity of DAT1 was associated with reduced performance and a lack of increased basal ganglia involvement under higher working memory demands.
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Bédard AC, Schulz KP, Cook EH, Fan J, Clerkin SM, Ivanov I, Halperin JM, Newcorn JH. Dopamine transporter gene variation modulates activation of striatum in youth with ADHD. Neuroimage 2009; 53:935-42. [PMID: 20026227 DOI: 10.1016/j.neuroimage.2009.12.041] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2009] [Revised: 12/07/2009] [Accepted: 12/09/2009] [Indexed: 10/20/2022] Open
Abstract
Polymorphisms in the 3'UTR variable number tandem repeat (VNTR) of exon 15 of the dopamine transporter gene (DAT1) have been linked to attention-deficit hyperactivity disorder (ADHD); moreover, variability in DAT1 3'UTR genotype may contribute to both heterogeneity of the ADHD phenotype and differences in response to stimulant medications. The impact of this VNTR on neuronal function in individuals with ADHD remains unclear despite evidence that the polymorphisms influence dopamine transporter expression. Thus, we used event-related functional magnetic resonance imaging to examine the impact of DAT1 3'UTR genotype on brain activation during response inhibition in unmedicated children and adolescents with ADHD. Twenty-one youth with ADHD who were homozygous for the 10-repeat (10R) allele of the DAT1 3'UTR and 12 youth who were carriers of the 9-repeat (9R) allele were scanned while they performed a Go/No-Go task. Response inhibition was modeled by contrasting activation during correct No-Go trials versus correct Go trials. Participants who were homozygous for the DAT1 3'UTR 10R allele and those who had a single 9R allele did not differ on percent of trials with successful inhibition, which was the primary measure of inhibitory control. Yet, youth with the DAT1 3'UTR 10R/10R genotype had significantly greater inhibitory control-related activation than those with one 9R allele in the left striatum, right dorsal premotor cortex, and bilaterally in the temporoparietal cortical junction. These findings provide preliminary evidence that neural activity related to inhibitory control may differ as a function of DAT1 3'UTR genotype in youth with ADHD.
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Affiliation(s)
- Anne-Claude Bédard
- Department of Psychiatry, Mount Sinai School of Medicine, Box 1230, One Gustave L. Levy Place, New York, NY 10029, USA
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Haile CN, Kosten TR, Kosten TA. Pharmacogenetic treatments for drug addiction: cocaine, amphetamine and methamphetamine. THE AMERICAN JOURNAL OF DRUG AND ALCOHOL ABUSE 2009; 35:161-77. [PMID: 19462300 DOI: 10.1080/00952990902825447] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
BACKGROUND Pharmacogenetics uses genetic variation to predict individual differences in response to medications and holds much promise to improve treatment of addictive disorders. OBJECTIVES To review how genetic variation affects responses to cocaine, amphetamine, and methamphetamine and how this information may guide pharmacotherapy. METHODS We performed a cross-referenced literature search on pharmacogenetics, cocaine, amphetamine, and methamphetamine. RESULTS We describe functional genetic variants for enzymes dopamine-beta-hydroxylase (DbetaH), catechol-O-methyltransferase (COMT), and dopamine transporter (DAT1), dopamine D4 receptor, and brain-derived neurotrophic factor (BDNF). A single nucleotide polymorphism (SNP; C-1021T) in the DbetaH gene is relevant to paranoia associated with disulfiram pharmacotherapy for cocaine addiction. Individuals with variable number tandem repeats (VNTR) of the SLC6A3 gene 3'-untranslated region polymorphism of DAT1 have altered responses to drugs. The 10/10 repeat respond poorly to methylphenidate pharmacotherapy and the 9/9 DAT1 variant show blunted euphoria and physiological response to amphetamine. COMT, D4 receptor, and BDNF polymorphisms are linked to methamphetamine abuse and psychosis. CONCLUSIONS Disulfiram and methylphenidate pharmacotherapies for cocaine addiction are optimized by considering polymorphisms affecting DbetaH and DAT1 respectively. Altered subjective effects for amphetamine in DAT1 VNTR variants suggest a 'protected' phenotype. SCIENTIFIC SIGNIFICANCE Pharmacogenetic-based treatments for psychostimulant addiction are critical for successful treatment.
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Affiliation(s)
- Colin N Haile
- Menninger Department of Psychiatry and Behavioral Sciences, Baylor College of Medicine, and Michael E DeBakey VA Medical Center, Houston, Texas 77030, USA
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Hesse S, Ballaschke O, Barthel H, Sabri O. Dopamine transporter imaging in adult patients with attention-deficit/hyperactivity disorder. Psychiatry Res 2009; 171:120-8. [PMID: 19176281 DOI: 10.1016/j.pscychresns.2008.01.002] [Citation(s) in RCA: 57] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/13/2007] [Revised: 12/03/2007] [Accepted: 01/07/2008] [Indexed: 10/21/2022]
Abstract
The aim of this study was to provide in vivo evidence for the hypothesis that dopaminergic neurotransmission is altered in adult patients with attention-deficit/hyperactivity disorder (ADHD). We used high-resolution brain-dedicated single-photon emission computed tomography and the dopamine transporter (DAT) marker [(123)I]FP-CIT in 17 adult treatment-naïve ADHD patients and 14 age-matched controls. Magnetic resonance imaging-based region of interest analysis was performed to quantify the DAT availability (expressed as a ratio of specific to non-displaceable binding, V(3)'') in the striatum. Additionally, the specific radiotracer binding was assessed in the thalamus and the midbrain/brainstem regions (reflecting also the availability of the serotonin transporter to which [(123)I]FP-CIT binds with moderate affinity). In the striatal areas of the ADHD patients, a significantly reduced specific tracer binding was found (V(3)'': 5.18+/-0.98; controls 6.36+/-1.34). In contrast, the specific [(123)I]FP-CIT binding did not differ from controls in the thalamus and midbrain/brainstem areas. These data indicate a reduced dopaminergic but not serotonergic transmitter reuptake function in adult ADHD. Further studies will have to deal with the question of whether these findings have the potential to influence treatment decisions in this complex disorder.
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Affiliation(s)
- Swen Hesse
- Department of Nuclear Medicine, University of Leipzig, Leipzig, Germany.
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Krause J. SPECT and PET of the dopamine transporter in attention-deficit/hyperactivity disorder. Expert Rev Neurother 2008; 8:611-25. [PMID: 18416663 DOI: 10.1586/14737175.8.4.611] [Citation(s) in RCA: 78] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Abnormalities of frontostriatal circuits, which are modulated by dopamine, have been found by brain imaging studies in patients with attention-deficit/hyperactivity disorder (ADHD). With special radiolabeled ligands selective imaging of the dopamine transporter (DAT), which has a key function in dopamine metabolism, can be performed by SPECT and PET. Most of the studies showed a higher DAT availability in untreated patients with ADHD compared with controls. The relationship between DAT availability and a polymorphism of DAT1 gene in patients with ADHD is not clear and the results are controversial. It has been shown that methylphenidate lowers DAT availability very effectively in normal people and in patients with ADHD. First results seem to indicate that nonresponders to methylphenidate among ADHD patients have a low primary DAT availability, whereas patients with a good response to the drug have high DAT. Nicotine seems to lower DAT availability such as stimulant medication; this may explain the high percentage of smokers among patients with ADHD. Zinc is a DAT inhibitor and seems to have a positive therapeutic effect on ADHD symptoms. This article reviews the function and structure of the DAT, the results of DAT imaging with SPECT and PET, the relations between DAT availability and the DAT1 gene polymorphism, the influence of stimulants on DAT and the significance of DAT for therapeutic response, nicotine, zinc and psychotic symptoms in patients with ADHD.
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Kooij JS, Boonstra AM, Vermeulen SH, Heister AG, Burger H, Buitelaar JK, Franke B. Response to methylphenidate in adults with ADHD is associated with a polymorphism in SLC6A3 (DAT1). Am J Med Genet B Neuropsychiatr Genet 2008; 147B:201-8. [PMID: 17955457 DOI: 10.1002/ajmg.b.30586] [Citation(s) in RCA: 61] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
In this pharmacogenetic study in adults with ADHD (n = 42), a stratified analysis was performed of the association between response to methylphenidate (MPH), assessed under double-blind conditions, and polymorphisms in the genes encoding the dopamine transporter, SLC6A3 (DAT1), the norepinephrine transporter, SLC6A2 (NET), and the dopamine receptor D4, DRD4. The VNTR polymorphism in the 3' untranslated region of SLC6A3 was significantly associated with an increased likelihood of a response to MPH treatment (OR 3.8; 95% CI 1.0-15.2, and OR 5.4; 95% CI 1.4-21.9, depending on the definition of response) in carriers of a single 10-repeat allele compared to patients with the 10/10 genotype. The polymorphisms in DRD4 and the SLC6A2 were not associated with treatment response. This study supports a role of the SLC6A3 genotype in determining the response to MPH in the treatment of adults with ADHD.
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Affiliation(s)
- J Sandra Kooij
- PsyQ, Psycho-Medical Programs, The Hague, The Netherlands.
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Interaction of dopamine transporter genotype with prenatal smoke exposure on ADHD symptoms. J Pediatr 2008; 152:263-9. [PMID: 18206700 DOI: 10.1016/j.jpeds.2007.07.004] [Citation(s) in RCA: 100] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/06/2006] [Revised: 05/14/2007] [Accepted: 07/02/2007] [Indexed: 11/24/2022]
Abstract
OBJECTIVE To demonstrate that children homozygous for the 10-repeat allele of the common dopamine transporter (DAT1) polymorphism who were exposed to maternal prenatal smoke exhibited significantly higher hyperactivity-impulsivity than children without these environmental or genetic risks. STUDY DESIGN We performed a prospective longitudinal study from birth into early adulthood monitoring the long-term outcome of early risk factors. Maternal prenatal smoking was determined during a standardized interview with the mother when the child was 3 months old. At age 15 years, 305 adolescents participated in genotyping for the DAT1 40 base pair variable number of tandem repeats polymorphism and assessment of inattention, hyperactivity-impulsivity, and oppositional defiant/conduct disorder symptoms with the Kiddie-Sads-Present and Lifetime Version. RESULTS There was no bivariate association between DAT1 genotype, prenatal smoke exposure and symptoms of attention deficit hyperactivity disorder. However, a significant interaction between DAT1 genotype and prenatal smoke exposure emerged (P = .012), indicating that males with prenatal smoke exposure who were homozygous for the DAT1 10r allele had higher hyperactivity-impulsivity than males from all other groups. In females, no significant main effects of DAT1 genotype or prenatal smoke exposure or interaction effects on any symptoms were evident (all P > .25). CONCLUSIONS This study provides further evidence for the multifactorial nature of attention deficit hyperactivity disorder and the importance of studying both genetic and environmental factors and their interaction.
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Kung HF, Kung MP, Wey SP, Lin KJ, Yen TC. Clinical acceptance of a molecular imaging agent: a long march with [99mTc]TRODAT. Nucl Med Biol 2007; 34:787-9. [DOI: 10.1016/j.nucmedbio.2007.03.010] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2007] [Accepted: 03/19/2007] [Indexed: 10/23/2022]
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