Cortical thinning in preschoolers with maladaptive guilt.

Maladaptive guilt is a central symptom of preschool-onset depression associated with severe psychopathology in adolescence and adulthood. Although studies have found that maladaptive guilt is associated with structural alterations in the anterior insula (AI) and dorsomedial prefrontal cortex (dmPFC) in middle childhood and adolescence, no study has examined structural neural correlates of maladaptive guilt in preschool, when this symptom first emerges. This study examined a pooled sample of 3-to 6-year-old children (N = 76; 40.8% female) from two studies, both which used the same type of magnetic resonance imaging scanner and conducted diagnostic interviews for depression that included clinician ratings of whether children met criteria for maladaptive guilt. Preschoolers with maladaptive guilt displayed significantly thinner dmPFC than children without this symptom. Neither children's depressive severity nor their vegetative or other emotional symptoms of depression were associated with dmPFC thickness, suggesting that dmPFC thinning is specific to maladaptive guilt. Neither AI gray matter volume or thickness nor dmPFC gray matter volume differed between children with and without maladaptive guilt. This study is the first to identify a structural biomarker for a specific depressive symptom in preschool. Findings may inform neurobiological models of the development of depression and aid in detection of this symptom.