title: The relationship of impulsivity and cortical thickness in depressed and non-depressed adolescents.
abstract: Major Depressive Disorder (MDD) is recognized to be heterogeneous in terms of brain structure abnormality findings across studies, which might reflect previously unstudied traits that confer variability to neuroimaging measurements. The purpose of this study was to examine the relationships between different types of trait impulsivity and MDD diagnosis on adolescent brain structure. We predicted that adolescents with depression who were high on trait impulsivity would have more abnormal cortical structure than depressed patients or non-MDD who were low on impulsivity. We recruited 58 subjects, including 29 adolescents (ages 12-19) with a primary DSM-IV diagnosis of MDD and a history of suicide attempt and 29 demographically-matched healthy control participants. Our GLM-based analyses sought to describe differences in the linear relationships between cortical thickness and impulsivity trait levels. As hypothesized, we found significant moderation effects in rostral middle frontal gyrus and right paracentral lobule cortical thickness for different subscales of the Barratt Impulsiveness Scale. However, although these brain-behavior relationships differed between diagnostic study groups, they were not simple additive effects as we had predicted. For the middle frontal gyrus, non-MDD participants showed a strong positive association between cortical thickness and BIS-11 Motor scores, while MDD-diagnosed participants showed a negative association. For Non-Planning Impulsiveness, paracentral lobule cortical thickness was observed with greater impulsivity in MDD, but no association was found for controls. In conclusion, the findings confirm that dimensions of impulsivity have discrete neural correlates, and show that relationships between impulsivity and brain structure are expressed differently in adolescents with MDD compared to non-MDD.
authors.affiliation: Department of Psychiatry, Rutgers University Robert Wood Johnson Medical School, 675 Hoes Ln W, Piscataway, NJ, 08854, USA.
authors.forename: Yuli
authors.initials: Y
authors.lastname: Fradkin
authors.affiliation: Olin Neuropsychiatry Research Center, Hartford Hospital / The Institute of Living, 200 Retreat Avenue, Whitehall Building, Hartford, CT, 06106, USA.
authors.forename: Sabin
authors.initials: S
authors.lastname: Khadka
authors.affiliation: Olin Neuropsychiatry Research Center, Hartford Hospital / The Institute of Living, 200 Retreat Avenue, Whitehall Building, Hartford, CT, 06106, USA.
authors.forename: Katie L
authors.initials: KL
authors.lastname: Bessette
authors.affiliation: Olin Neuropsychiatry Research Center, Hartford Hospital / The Institute of Living, 200 Retreat Avenue, Whitehall Building, Hartford, CT, 06106, USA. Michael.Stevens@hhchealth.org.|Department of Psychiatry, Yale University School of Medicine, New Haven, CT, USA. Michael.Stevens@hhchealth.org.
authors.forename: Michael C
authors.initials: MC
authors.lastname: Stevens
mesh_terms: D000293:Adolescent; D002540:Cerebral Cortex / Q000000981:diagnostic imaging* / Q000473:pathology; D002648:Child; D003865:Major Depressive Disorder / Q000000981:diagnostic imaging* / Q000473:pathology / Q000523:psychology*; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D007175:Impulsive Behavior; D016014:Linear Models; D008279:Magnetic Resonance Imaging; D008297:Male; D009483:Neuropsychological Tests; D009929:Organ Size; D013406:Suicide, Attempted
keywords: Cortical thickness; Depression; Impulsivity; MRI