Superior Parietal Volume in Adolescents with a History of Trauma

Objective: Early trauma exposure has been demonstrated to significantly impact brain volume. Childhood trauma also contributes to onset of psychopathology, particularly depression. We sought to identify gray matter volume changes unique to trauma exposure in adolescent depression and hypothesized that adolescents with diagnosis of major depressive disorder (MDD) and childhood trauma would have smaller gray matter volume and thickness in areas previously identified as reduced with childhood trauma exposure relative to non-traumatized depressed adolescents and healthy controls. Methods: We obtained structural MRI scans for 120 adolescents with a history of past trauma exposure and a current diagnosis major depressive disorder (MDD, n=29), a diagnosis of MDD, but no trauma exposure (n=49), and healthy controls (n=42). Adolescents with a diagnosis of MDD and trauma exposure compared with adolescents with MDD and no history of trauma exposure showed increased gray matter volume in the right superior parietal lobe (p=0.001), a cortical region important for processing of visuospatial cues and implicated in traumatic memory. Positive trauma history status included sexual or physical abuse, or trauma with risk of death or bodily harm. Results: Our findings indicate increased right superior parietal volume in depressed adolescents with history of trauma exposure that is distinct from findings related to depression or suicidal behavior. Conclusion: Our finding of increased superior parietal volume in adolescents exposed to past trauma compared with adolescents not exposed to past trauma may indicate differences in information processing, particularly visuospatial processing and working memory, in trauma exposed, depressed adolescents. The absence of any significant relationships between superior parietal lobe volume abnormality and measures of present symptom severity, suicidal ideation, past suicide attempt and medication in adolescents with history of depression and past trauma suggests that increased right superior parietal lobe volume may be related to trauma exposure in adolescents with depression.