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Cubillo A, Hermes H, Berger E, Winkel K, Schunk D, Fehr E, Hare TA. Intra-individual variability in task performance after cognitive training is associated with long-term outcomes in children. Dev Sci 2023; 26:e13252. [PMID: 35184350 PMCID: PMC10078259 DOI: 10.1111/desc.13252] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2021] [Revised: 11/22/2021] [Accepted: 02/04/2022] [Indexed: 12/15/2022]
Abstract
The potential benefits and mechanistic effects of working memory training (WMT) in children are the subject of much research and debate. We show that after five weeks of school-based, adaptive WMT 6-9 year-old primary school children had greater activity in prefrontal and striatal brain regions, higher task accuracy, and reduced intra-individual variability in response times compared to controls. Using a sequential sampling decision model, we demonstrate that this reduction in intra-individual variability can be explained by changes to the evidence accumulation rates and thresholds. Critically, intra-individual variability is useful in quantifying the immediate impact of cognitive training interventions, being a better predictor of academic skills and well-being 6-12 months after the end of training than task accuracy. Taken together, our results suggest that attention control is the initial mechanism that leads to the long-run benefits from adaptive WMT. Selective and sustained attention abilities may serve as a scaffold for subsequent changes in higher cognitive processes, academic skills, and general well-being. Furthermore, these results highlight that the selection of outcome measures and the timing of the assessments play a crucial role in detecting training efficacy. Thus, evaluating intra-individual variability, during or directly after training could allow for the early tailoring of training interventions in terms of duration or content to maximise their impact.
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Affiliation(s)
- Ana Cubillo
- Zurich Center for Neuroeconomics, Department of Economics, University of Zurich, Zurich, Switzerland.,Department of Child and Adolescent Psychiatry, University Psychiatric Clinics Basel, Basel, Switzerland
| | - Henning Hermes
- DICE, Heinrich Heine University of Dusseldorf, Dusseldorf, Germany
| | - Eva Berger
- Chair of Public and Behavioral Economics, Johannes Gutenberg University of Mainz, Mainz, Germany
| | - Kirsten Winkel
- Chair of Statistics and Econometrics, Johannes Gutenberg University of Mainz, Mainz, Germany
| | - Daniel Schunk
- Chair of Public and Behavioral Economics, Johannes Gutenberg University of Mainz, Mainz, Germany
| | - Ernst Fehr
- Zurich Center for Neuroeconomics, Department of Economics, University of Zurich, Zurich, Switzerland
| | - Todd A Hare
- Zurich Center for Neuroeconomics, Department of Economics, University of Zurich, Zurich, Switzerland
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2
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Bora E, Özerdem A. A meta-analysis of neurocognition in youth with familial high risk for bipolar disorder. Eur Psychiatry 2020; 44:17-23. [DOI: 10.1016/j.eurpsy.2017.02.483] [Citation(s) in RCA: 51] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/31/2016] [Revised: 02/11/2017] [Accepted: 02/12/2017] [Indexed: 12/11/2022] Open
Abstract
AbstractObjective:Neuropsychological impairment, including deficits in social cognition is evident in subjects at genetic high-risk for psychosis. However, findings in youth at genetic risk to bipolar disorder (BP) have been suggested to be less supportive of premorbid deficits. We aimed to conduct a meta-analysis of cognitive deficits in youth with familiar risk for bipolar disorder (FHR-BD).Methods:A novel meta-analysis of FHR-BD (mean age 10–25), including 18 studies (786 offsprings/siblings of patients with BD and 794 healthy controls), was conducted.Results:Both general cognition (d = 0.29, CI = 0.15–0.44) and social cognition (d = 0.23, CI = 0–0.45) were impaired in FHR-BD. In comparison to controls, FHR-BD had significant deficits in several cognitive domains, including visual memory (d = 0.35), verbal memory (d = 0.21), processing speed (d = 0.26) and sustained attention (d = 0.36). There was no significant difference between FHR-BD and controls in planning and working memory.Conclusions:Cognitive deficits are evident in individuals who are at genetic high-risk for developing BD. Neurodevelopmental abnormalities are likely playing a role not only in schizophrenia but also in BD.
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Michelini G, Kitsune V, Vainieri I, Hosang GM, Brandeis D, Asherson P, Kuntsi J. Shared and Disorder-Specific Event-Related Brain Oscillatory Markers of Attentional Dysfunction in ADHD and Bipolar Disorder. Brain Topogr 2018; 31:672-689. [PMID: 29417321 PMCID: PMC5999167 DOI: 10.1007/s10548-018-0625-z] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2017] [Accepted: 01/25/2018] [Indexed: 12/28/2022]
Abstract
Attention-deficit/hyperactivity disorder (ADHD) and bipolar disorder (BD) often present with overlapping symptoms and cognitive impairments, such as increased fluctuations in attentional performance measured by increased reaction-time variability (RTV). We previously provided initial evidence of shared and distinct event-related potential (ERP) impairments in ADHD and BD in a direct electrophysiological comparison, but no study to date has compared neural mechanisms underlying attentional impairments with finer-grained brain oscillatory markers. Here, we aimed to compare the neural underpinnings of impaired attentional processes in ADHD and BD, by examining event-related brain oscillations during a reaction-time task under slow-unrewarded baseline and fast-incentive conditions. We measured cognitive performance, ERPs and brain-oscillatory modulations of power and phase variability in 20 women with ADHD, 20 women with BD (currently euthymic) and 20 control women. Compared to controls, both ADHD and BD groups showed increased RTV in the baseline condition and increased RTV, theta phase variability and lower contingent negative variation in the fast-incentive condition. Unlike controls, neither clinical group showed an improvement from the slow-unrewarded baseline to the fast-incentive condition in attentional P3 amplitude or alpha power suppression. Most impairments did not differ between the disorders, as only an adjustment in beta suppression between conditions (lower in the ADHD group) distinguished between the clinical groups. These findings suggest shared impairments in women with ADHD and BD in cognitive and neural variability, preparatory activity and inability to adjust attention allocation and activation. These overlapping impairments may represent shared neurobiological mechanisms of attentional dysfunction in ADHD and BD, and potentially underlie common symptoms in both disorders.
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Affiliation(s)
- Giorgia Michelini
- Institute of Psychiatry, Psychology and Neuroscience, Social, Genetic and Developmental Psychiatry Centre, King's College London, De Crespigny Park, London, SE5 8AF, UK
| | - Viryanaga Kitsune
- Institute of Psychiatry, Psychology and Neuroscience, Social, Genetic and Developmental Psychiatry Centre, King's College London, De Crespigny Park, London, SE5 8AF, UK
| | - Isabella Vainieri
- Institute of Psychiatry, Psychology and Neuroscience, Social, Genetic and Developmental Psychiatry Centre, King's College London, De Crespigny Park, London, SE5 8AF, UK
| | - Georgina M Hosang
- Centre for Psychiatry, Wolfson Institute of Preventive Medicine, Barts & The London School of Medicine & Dentistry, Queen Mary, University of London, London, UK
| | - Daniel Brandeis
- Department of Child and Adolescent Psychiatry and Psychotherapy, Central Institute of Mental Health, Medical Faculty Mannheim/Heidelberg University, Mannheim, Germany.,Department of Child and Adolescent Psychiatry and Psychotherapy, Psychiatric Hospital, University of Zurich, Zurich, Switzerland.,Center for Integrative Human Physiology, University of Zurich, Zurich, Switzerland.,Neuroscience Center Zurich, University of Zurich, Zurich, Switzerland
| | - Philip Asherson
- Institute of Psychiatry, Psychology and Neuroscience, Social, Genetic and Developmental Psychiatry Centre, King's College London, De Crespigny Park, London, SE5 8AF, UK
| | - Jonna Kuntsi
- Institute of Psychiatry, Psychology and Neuroscience, Social, Genetic and Developmental Psychiatry Centre, King's College London, De Crespigny Park, London, SE5 8AF, UK.
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Pagliaccio D, Wiggins JL, Adleman NE, Harkins E, Curhan A, Towbin KE, Brotman MA, Pine DS, Leibenluft E. Behavioral and Neural Sustained Attention Deficits in Bipolar Disorder and Familial Risk of Bipolar Disorder. Biol Psychiatry 2017; 82:669-678. [PMID: 27837919 PMCID: PMC5354995 DOI: 10.1016/j.biopsych.2016.09.006] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/24/2016] [Revised: 09/02/2016] [Accepted: 09/02/2016] [Indexed: 12/22/2022]
Abstract
BACKGROUND Few neuroimaging studies compare individuals affected with bipolar disorder (BP), at high familial risk of BP, and at low risk to identify endophenotypes for BP. None have examined variability in attention, despite promising behavioral work in this area. We used functional magnetic resonance imaging (fMRI) methods uniquely powered to compare the neural correlates of attention variability in these three groups. METHODS The present study examined 8- to 25-year-old individuals (n = 106) who completed an fMRI attention task: 24 with BP, 29 at risk based on a first-degree relative with BP, and 53 healthy, low-risk individuals. Group differences in intrasubject variability in reaction time were examined, and a sophisticated fMRI analytic approach was used to quantify precisely trialwise associations between reaction time and brain activity. The latter has not been examined previously in BP or risk of BP. RESULTS Relative to healthy individuals, those with BP or at risk for BP exhibited increased reaction time variability (F2,102 = 4.26, p = .02, ηp2 = .08). Importantly, we identified blunted relationships between trialwise variation in reaction time and brain activity in the inferior and middle frontal gyri, precuneus, cingulate cortex, caudate, and postcentral gyrus (all regions: p < .001, ηp2 > .06) in both at-risk and BP individuals compared with healthy, low-risk individuals. This blunting partially mediated group differences in reaction time variability (β = .010, 95% confidence interval 0.002 to 0.020, Sobel Z = 2.08, p = .038). CONCLUSIONS Blunting in key frontal, cingulate, and striatal areas was evident in unaffected, at-risk individuals and in euthymic BP patients. Elucidating such novel neural endophenotypes can facilitate new approaches to BP prediction, diagnosis, and prevention.
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Affiliation(s)
- David Pagliaccio
- Emotion and Development Branch, National Institute of Mental Health, National Institutes of Health, Bethesda.
| | - Jillian Lee Wiggins
- Department of Psychology, San Diego State University, San Diego, California; Joint Doctoral Program in Clinical Psychology, San Diego State University/University of California, San Diego, San Diego, California
| | - Nancy E Adleman
- Department of Psychology, The Catholic University of America, Washington, DC
| | | | - Alexa Curhan
- Emotion and Development Branch, National Institute of Mental Health, National Institutes of Health, Bethesda
| | - Kenneth E Towbin
- Emotion and Development Branch, National Institute of Mental Health, National Institutes of Health, Bethesda
| | - Melissa A Brotman
- Emotion and Development Branch, National Institute of Mental Health, National Institutes of Health, Bethesda
| | - Daniel S Pine
- Emotion and Development Branch, National Institute of Mental Health, National Institutes of Health, Bethesda
| | - Ellen Leibenluft
- Emotion and Development Branch, National Institute of Mental Health, National Institutes of Health, Bethesda
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Gruber SA, Dahlgren MK, Sagar KA, Gonenc A, Norris L, Cohen BM, Ongur D, Lewandowski KE. Decreased Cingulate Cortex activation during cognitive control processing in bipolar disorder. J Affect Disord 2017; 213:86-95. [PMID: 28199893 DOI: 10.1016/j.jad.2017.02.003] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/20/2016] [Accepted: 02/05/2017] [Indexed: 01/10/2023]
Abstract
BACKGROUND Cognitive deficits are well-documented in patients with bipolar disorder (BPD) and may impact the efficacy of psychotherapy. Cognitive control, a form of executive functioning, is often used therapeutically to shift patients' thoughts and behaviors from automatic, maladaptive responses to adaptive coping strategies. This study examined cognitive control processing in patients with BPD using the Multi-Source Interference Task (MSIT). METHOD Twenty-nine patients diagnosed with BPD and 21 healthy control (HC) subjects completed the MSIT with concurrent functional magnetic resonance imaging (fMRI). RESULTS Patients with BPD generally performed worse on the MSIT relative to HC participants; the BPD group had significantly lower performance accuracy and made more omission errors. Further, fMRI analyses revealed differential patterns of activation between the groups during the MSIT. Region of interest (ROI) analyses revealed that relative to HC participants, patients with BPD activated significantly fewer voxels within the cingulate cortex (CC) and more voxels within prefrontal cortex (PFC), although the PFC findings did not survive more stringent significance thresholds. LIMITATIONS Patients and HCs were not matched for age, sex, and premorbid verbal IQ, however, these variables were controlled for statistically. Medication usage in the BPD group may have possibly impacted the results. Given a priori hypotheses, ROI analyses were utilized. CONCLUSIONS Decreased CC activation and increased PFC activation may be associated with impaired cognitive control, demonstrated by BPD patients when completing the MSIT. Identifying the neural mechanisms which underlie key cognitive abnormalities in BPD may aid in clarifying the pathophysiology of this disorder and inform selection of potential targets for cognition remediation in BPD.
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Affiliation(s)
- Staci A Gruber
- Cognitive and Clinical Neuroimaging Core, McLean Imaging Center, McLean Hospital, 115 Mill Street, Belmont, MA 02478, United States; Department of Psychiatry, Harvard Medical School, Boston, MA 02215, United States.
| | - M Kathryn Dahlgren
- Cognitive and Clinical Neuroimaging Core, McLean Imaging Center, McLean Hospital, 115 Mill Street, Belmont, MA 02478, United States; Department of Psychology, Tufts University, Medford, MA 02155, United States
| | - Kelly A Sagar
- Cognitive and Clinical Neuroimaging Core, McLean Imaging Center, McLean Hospital, 115 Mill Street, Belmont, MA 02478, United States; Department of Psychiatry, Harvard Medical School, Boston, MA 02215, United States
| | - Atilla Gonenc
- Cognitive and Clinical Neuroimaging Core, McLean Imaging Center, McLean Hospital, 115 Mill Street, Belmont, MA 02478, United States; Department of Psychiatry, Harvard Medical School, Boston, MA 02215, United States
| | - Lesley Norris
- Schizophrenia and Bipolar Disorders Research Program, McLean Hospital, 115 Mill Street, Belmont, MA 02478, United States
| | - Bruce M Cohen
- Department of Psychiatry, Harvard Medical School, Boston, MA 02215, United States; Program for Neuropsychiatric Research, McLean Hospital, 115 Mill Street, Belmont, MA 02478, United States
| | - Dost Ongur
- Department of Psychiatry, Harvard Medical School, Boston, MA 02215, United States; Schizophrenia and Bipolar Disorders Research Program, McLean Hospital, 115 Mill Street, Belmont, MA 02478, United States; Program for Neuropsychiatric Research, McLean Hospital, 115 Mill Street, Belmont, MA 02478, United States
| | - Kathryn E Lewandowski
- Department of Psychiatry, Harvard Medical School, Boston, MA 02215, United States; Schizophrenia and Bipolar Disorders Research Program, McLean Hospital, 115 Mill Street, Belmont, MA 02478, United States
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Miskowiak KW, Kjærstad HL, Meluken I, Petersen JZ, Maciel BR, Köhler CA, Vinberg M, Kessing LV, Carvalho AF. The search for neuroimaging and cognitive endophenotypes: A critical systematic review of studies involving unaffected first-degree relatives of individuals with bipolar disorder. Neurosci Biobehav Rev 2017; 73:1-22. [DOI: 10.1016/j.neubiorev.2016.12.011] [Citation(s) in RCA: 64] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2016] [Revised: 10/05/2016] [Accepted: 12/09/2016] [Indexed: 12/16/2022]
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Cardenas SA, Kassem L, Brotman MA, Leibenluft E, McMahon FJ. Neurocognitive functioning in euthymic patients with bipolar disorder and unaffected relatives: A review of the literature. Neurosci Biobehav Rev 2016; 69:193-215. [PMID: 27502749 DOI: 10.1016/j.neubiorev.2016.08.002] [Citation(s) in RCA: 43] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2016] [Revised: 07/28/2016] [Accepted: 08/01/2016] [Indexed: 12/31/2022]
Abstract
BACKGROUND Neurocognitive deficits are present in bipolar disorder (BD) patients and their unaffected (nonbipolar) relatives, but it is not clear which domains are most often impaired and the extent of the impairment resulting from shared genetic factors. In this literature review, we address these issues and identify specific neurocognitive tasks most sensitive to cognitive deficits in patients and unaffected relatives. METHOD We conducted a systematic review in Web of Science, PubMed/Medline and PsycINFO databases. RESULTS Fifty-one articles assessing cognitive functioning in BD patients (23 studies) and unaffected relatives (28 studies) were examined. Patients and, less so, relatives show impairments in attention, processing speed, verbal learning/memory, and verbal fluency. CONCLUSION Studies were more likely to find impairment in patients than relatives, suggesting that some neurocognitive deficits may be a result of the illness itself and/or its treatment. However, small sample sizes, differences among relatives studied (e.g., relatedness, diagnostic status, age), and differences in assessment instruments may contribute to inconsistencies in reported neurocognitive performance among relatives. Additional studies addressing these issues are needed.
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Affiliation(s)
- Stephanie A Cardenas
- National Institutes of Health, 10 Center Drive, RM 3D54, MSC 1264, Bethesda, MD 20814-1264, USA.
| | - Layla Kassem
- National Institutes of Health, 35 Convent Drive, RM 1A202, MSC 3719, Bethesda, MD 20892-3719, USA.
| | - Melissa A Brotman
- National Institutes of Health, 15K North Drive, Room 211, Bethesda, MD 20892, USA.
| | - Ellen Leibenluft
- National Institutes of Health, 15K North Drive, RM 210, MSC 2670 Bethesda, MD 20892-2670, USA.
| | - Francis J McMahon
- National Institutes of Health, 35 Convent Drive, RM 1A201, MSC 3719, Bethesda, MD, 20892-3719, USA.
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Commonalities in EEG Spectral Power Abnormalities Between Women With ADHD and Women With Bipolar Disorder During Rest and Cognitive Performance. Brain Topogr 2016; 29:856-866. [PMID: 27464584 PMCID: PMC5054048 DOI: 10.1007/s10548-016-0508-0] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2016] [Accepted: 07/13/2016] [Indexed: 11/28/2022]
Abstract
While attention-deficit/hyperactivity disorder (ADHD) and bipolar disorder (BD) denote distinct psychiatric conditions, diagnostic delineation is impeded by considerable symptomatic overlap. Direct comparisons across ADHD and BD on neurophysiological measures are limited. They could inform us on impairments that are specific to or shared between the disorders and, therefore, potential biomarkers that may aid in the identification of the diagnostic boundaries. Our aim was to test whether quantitative EEG (QEEG) identifies differences or similarities between women with ADHD and women with BD during resting-state and task conditions. QEEG activity was directly compared between 20 ADHD, 20 BD and 20 control women during an eyes-open resting-state condition (EO) and a cued continuous performance task (CPT-OX). Both ADHD (t38 = 2.50, p = 0.017) and BD (t38 = 2.54, p = 0.018) participants showed higher absolute theta power during EO than controls. No significant differences emerged between the two clinical groups. While control participants showed a task-related increase in absolute theta power from EO to CPT-OX (t19 = −3.77, p = 0.001), no such change in absolute theta power was observed in the ADHD (t19 = −0.605, p = 0.553) or BD (t19 = 1.82, p = 0.084) groups. Our results provide evidence for commonalities in brain dysfunction between ADHD and BD. Absolute theta power may play a role as a marker of neurobiological processes in both disorders.
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Adleman NE, Chen G, Reynolds RC, Frackman A, Razdan V, Weissman DH, Pine DS, Leibenluft E. Age-related differences in the neural correlates of trial-to-trial variations of reaction time. Dev Cogn Neurosci 2016; 19:248-57. [PMID: 27239972 PMCID: PMC5099497 DOI: 10.1016/j.dcn.2016.05.001] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2015] [Revised: 05/06/2016] [Accepted: 05/08/2016] [Indexed: 12/31/2022] Open
Abstract
Intra-subject variation in reaction time (ISVRT) is a developmentally-important phenomenon that decreases from childhood through young adulthood in parallel with the development of executive functions and networks. Prior work has shown a significant association between trial-by-trial variations in reaction time (RT) and trial-by-trial variations in brain activity as measured by the blood-oxygenated level-dependent (BOLD) response in functional magnetic resonance imaging (fMRI) studies. It remains unclear, however, whether such "RT-BOLD" relationships vary with age. Here, we determined whether such trial-by-trial relationships vary with age in a cross-sectional design. We observed an association between age and RT-BOLD relationships in 11 clusters located in visual/occipital regions, frontal and parietal association cortex, precentral/postcentral gyrus, and thalamus. Some of these relationships were negative, reflecting increased BOLD associated with decreased RT, manifesting around the time of stimulus presentation and positive several seconds later. Critically for present purposes, all RT-BOLD relationships increased with age. Thus, RT-BOLD relationships may reflect robust, measurable changes in the brain-behavior relationship across development.
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Affiliation(s)
- Nancy E Adleman
- Department of Psychology, The Catholic University of America, 620 Michigan Ave., NE, Washington, DC 20064, USA; Emotion and Development Branch, National Institute of Mental Health, National Institutes of Health, 9000 Rockville Pike, Bethesda, MD 20892, USA.
| | - Gang Chen
- Scientific and Statistical Computing Core, National Institute of Mental Health, National Institutes of Health, 9000 Rockville Pike, Bethesda, MD 20892, USA.
| | - Richard C Reynolds
- Scientific and Statistical Computing Core, National Institute of Mental Health, National Institutes of Health, 9000 Rockville Pike, Bethesda, MD 20892, USA.
| | - Anna Frackman
- Emotion and Development Branch, National Institute of Mental Health, National Institutes of Health, 9000 Rockville Pike, Bethesda, MD 20892, USA.
| | - Varun Razdan
- Emotion and Development Branch, National Institute of Mental Health, National Institutes of Health, 9000 Rockville Pike, Bethesda, MD 20892, USA.
| | - Daniel H Weissman
- Department of Psychology, University of Michigan, 530 Church St, Ann Arbor, MI 48109, USA.
| | - Daniel S Pine
- Emotion and Development Branch, National Institute of Mental Health, National Institutes of Health, 9000 Rockville Pike, Bethesda, MD 20892, USA.
| | - Ellen Leibenluft
- Emotion and Development Branch, National Institute of Mental Health, National Institutes of Health, 9000 Rockville Pike, Bethesda, MD 20892, USA.
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Lin HY, Hwang-Gu SL, Gau SSF. Intra-individual reaction time variability based on ex-Gaussian distribution as a potential endophenotype for attention-deficit/hyperactivity disorder. Acta Psychiatr Scand 2015; 132:39-50. [PMID: 25612058 DOI: 10.1111/acps.12393] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 12/29/2014] [Indexed: 01/03/2023]
Abstract
OBJECTIVE Intra-individual variability in reaction time (IIV-RT), defined by standard deviation of RT (RTSD), is considered as an endophenotype for attention-deficit/hyperactivity disorder (ADHD). Ex-Gaussian distributions of RT, rather than RTSD, could better characterize moment-to-moment fluctuations in neuropsychological performance. However, data of response variability based on ex-Gaussian parameters as an endophenotypic candidate for ADHD are lacking. METHOD We assessed 411 adolescents with clinically diagnosed ADHD based on the DSM-IV-TR criteria as probands, 138 unaffected siblings, and 138 healthy controls. The output parameters, mu, sigma, and tau, of an ex-Gaussian RT distribution were derived from the Conners' continuous performance test. Multi-level models controlling for sex, age, comorbidity, and use of methylphenidate were applied. RESULTS Compared with unaffected siblings and controls, ADHD probands had elevated sigma value, omissions, commissions, and mean RT. Unaffected siblings formed an intermediate group in-between probands and controls in terms of tau value and RTSD. There was no between-group difference in mu value. Conforming to a context-dependent nature, unaffected siblings still had an intermediate tau value in-between probands and controls across different interstimulus intervals. CONCLUSION Our findings suggest IIV-RT represented by tau may be a potential endophenotype for inquiry into genetic underpinnings of ADHD in the context of heterogeneity.
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Affiliation(s)
- H-Y Lin
- Department of Psychiatry, National Taiwan University Hospital and College of Medicine, Taipei, Taiwan
| | - S-L Hwang-Gu
- Graduate Institute of Behavioral Sciences, College of Medicine, Chang Gung University, Tao-Yuan, Taiwan
| | - S S-F Gau
- Department of Psychiatry, National Taiwan University Hospital and College of Medicine, Taipei, Taiwan.,Department of Psychology, Graduate Institute of Brain and Mind Sciences, Graduate Institute of Epidemiology and Preventive Medicine, Graduate Institute of Clinical Medicine, National Taiwan University, Taipei, Taiwan
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