Further understanding of the comorbidity between attention-deficit/hyperactivity disorder and bipolar disorder in adults: An MRI study of cortical thickness

• Published in: Psychiatry research. Neuroimaging 2012-04, Vol.202 (1), p.1-11
• Main Authors: Makris, Nikos, Seidman, Larry J, Brown, Ariel, Valera, Eve M, Kaiser, Jonathan R, Petty, Carter R, Liang, Lichen, Aleardi, Megan, Boriel, Denise, Henderson, Carly S, Giddens, Michelle, Faraone, Stephen V, Spencer, Thomas J, Biederman, Joseph
• Format: Article
• Language: English
• Subjects: ADHD; Adolescent; Adult; Adult and adolescent clinical studies; Anatomy; Attention Deficit Disorder with Hyperactivity - complications; Attention Deficit Disorder with Hyperactivity - pathology; Attention deficit disorders. Hyperactivity; Attention deficit hyperactivity disorder; Biological and medical sciences; Bipolar disorder; Bipolar Disorder - complications; Bipolar Disorder - pathology; Bipolar disorders; BPD; Brain architecture; Cerebral Cortex - pathology; Child clinical studies; Comorbidity; Cortex; Cortical thickness; Female; Humans; Magnetic Resonance Imaging; Male; Medical sciences; Middle Aged; Mood disorders; MRI; Neuroimaging; Psychiatry; Psychology. Psychoanalysis. Psychiatry; Psychopathology. Psychiatry; Radiology; Regression analysis; Substantia grisea
• ISSN: 0925-4927; 1872-7506
• DOI: 10.1016/j.pscychresns.2011.11.003

Abstract Although Attention-Deficit/Hyperactivity Disorder (ADHD) and Bipolar Disorder (BPD) frequently co-occur and represent a particularly morbid clinical form of both disorders, neuroimaging research addressing this comorbidity is scarce. Our aim was to evaluate cortical thickness in ADHD and BPD, testing the hypothesis that comorbid subjects (ADHD + BPD) would have neuroanatomical correlates of both disorders. Magnetic Resonance Imaging (MRI) findings were compared between 31 adults with ADHD + BPD, 18 with BPD, 26 with ADHD, and 23 healthy controls. Cortical thickness analysis of regions of interest was estimated as a function of ADHD and BPD status, using linear regression models. BPD was associated with significantly thicker cortices in 13 regions, independently of ADHD status and ADHD was associated with significantly thinner neocortical gray matter in 28 regions, independent of BPD. In the comorbid state of ADHD plus BPD, the profile of cortical abnormalities consisted of structures that are altered in both disorders individually. Results support the hypothesis that ADHD and BPD independently contribute to cortical thickness alterations of selective and distinct brain structures, and that the comorbid state represents a combinatory effect of the two. Attention to comorbidity is necessary to help clarify the heterogeneous neuroanatomy of both BPD and ADHD.