Both childhood trauma (CT) and genetic factors contribute to the pathophysiology of depression. We studied the relationship of CT to age of onset (AO) of depression, personality traits, and expression of symptom dimensions in 324 adults with recurrent unipolar depression. Subjects received structured psychiatric interviews and completed CT, depressive symptom, and personality rating questionnaires. Experience of at least one type of trauma was reported by 79.9% of subjects, and the most common forms of trauma were physical neglect, emotional abuse, and emotional neglect. There was an earlier AO of depression in the groups that reported CT compared to those that reported none, with earliest AO occurring in those who had experienced the highest levels of CT. There were no significant correlations between overall CT scores and neuroticism or extraversion. Total CT was a significant (P=.008) predictor of the Mood symptom dimension, mostly accounted for by emotional abuse (P=.019), and physical neglect predicted the Anxiety symptom dimension (P=.002). All types of CT are commonly reported in individuals with depression, and emotional abuse and physical neglect, though previously less well identified, appear to have an important role in the pathogenesis of depressive disorders. The effect of CT on individuals with an underlying genetic vulnerability to depression may result in differences in depressive phenotype characterized by earlier AO of depression and the expression of specific depressive symptom dimensions.