Abstract
Stressful life events predict changes in brain structure and increases in psychopathology, but not everyone is equally affected by life stress. The learned helplessness theory posits that perceiving life stressors as uncontrollable leads to depression. Evidence supports this theory for youth, but the impact of perceived control diverges based on stressor type: perceived lack of control over dependent (self-generated) stressors is associated with greater depression symptoms when controlling for the frequency of stress exposure, but perceived control over independent (non-self-generated) stressors is not. However, it is unknown how perceived control over these stressor types is associated with brain structure. We tested whether perceived lack of control over dependent and independent life stressors, controlling for stressor exposure, is associated with gray matter (GM) in a priori regions of interest (ROIs; mPFC, hippocampus, amygdala) and across the cortex in a sample of 108 adolescents and emerging adults ages 14-22. There were no associations across the full sample between perceived control over either stressor type and GM in the ROIs. However, less perceived control over dependent stressors was associated with greater amygdala gray matter volume in female youth and greater medial prefrontal cortex thickness in male youth. Furthermore, whole-cortex analyses revealed less perceived control over dependent stressors was associated with greater GM thickness in cortical regions involved in cognitive and emotional regulation. Thus, appraisals of control have distinct associations with brain morphology while controlling for stressor frequency, highlighting the importance of differentiating between these aspects of the stress experience in future research.
