Abstract
BACKGROUND: Childhood adversity is a potent and modifiable risk factor for depression. Few studies have investigated how the developmental timing of adversity exposure shapes depression risk. We investigated whether there were sensitive periods, or age stages when two types of adversity (caregiver abuse, financial hardship) had stronger associations with depressive symptoms in late adolescence. METHODS: Data came from a prospective, longitudinal birth cohort of children in Avon, England (Avon Longitudinal Study of Parents and Children). Caregivers reported their children's adversity exposure at least seven times between 0 and 18 years of age. Child participants self-reported depressive symptoms (Short Mood and Feelings Questionnaire) at 18.5 years old. We used a structured life course modeling approach (SLCMA) to characterize how sensitive period and accumulation hypotheses explained variation in depressive symptoms. RESULTS: For females, accumulation best explained variation in depressive symptoms for both adversity types, with each additional developmental period of exposure associated with a 0.33-unit increase in depressive symptoms for caregiver abuse and 0.31-unit increase for financial hardship. For males, sensitive period hypotheses were selected for exposure to caregiver abuse (exposure at age 9 =2.13-unit and age 3.9 =1.46-unit increase), while an accumulation hypothesis was selected for exposure to financial hardship (0.40-unit increase in depression). CONCLUSIONS: Accumulation rather than sensitive period hypotheses generally best explained the relationship between adversity and depressive symptoms in late adolescence, but findings varied by sex and adversity type. These findings highlight the importance of considering multiple life course hypotheses, sex, and adversity type when investigating the downstream impacts of adversity.