Investigation of brain morphological changes in adolescents and adults with obsessive compulsive disorder via magnetic resonance imaging

The studies aiming to enlighten the neurobiology of Obsessive Compulsive Disorder (OCD) investigate the structural changes in brain yet there is no consensus. Some studies indicate cortical thinning with OCD while others show no specific change related to OCD. Studies on grey matter (GM) and white matter (WM) volume presents similar contrasting results. In this study, cortical thickness, GM and WM volume changes in adolescent and adult OCD patients were investigated. Fifteen adolescents and 25 adults diagnosed with OCD and age, sex, education matched 15 healthy adolescents and 22 healthy adults were included. Their T1 weighted structural MR images scanned by 3T MRI system were used. The GM and WM volumes of various cortical regions were obtained by CAT12. The average cortical thickness values were calculated with both CAT12 and FS6. OCD and healthy control group comparison for GM, WM and cortical thickness was conducted. Adolescent and adult subgroup comparison was carried as well. There was no significant difference on GM and WM volume in any anatomical region between OCD and healthy control groups. However, a cortical thinning in left frontal pole was observed in OCD. When adults and adolescents were considered separately, reduced cortical thickness in frontal areas with OCD was observed in adults; however, in adolescents, cortical thickness increase with OCD was observed in frontal and parietal regions. While the findings overall support the fronto-striatal model of OCD, the direction difference of cortical thickness alteration in adolescents and adults gives an interesting view on neurodevelopmental perspective of OCD.