The course, trajectories and predictors of depression 23 years after the 1988 Spitak earthquake in Armenia: A prospective cohort study

•Chronic and late-onset depression were common among long-term earthquake survivors.•Traumatic family deaths and lack of social support predicted chronic depression.•Late-onset depression was related to post-earthquake traumas and poverty.•At both assessments, depression was highly comorbid with anxiety and PTSD. There is a scarcity of long-term studies of depression after natural disasters. This prospective epidemiologic study evaluated the course of depression and factors associated with it among survivors 23-years post-earthquake. A geographically stratified subsample of 725 adults exposed to the Spitak earthquake was assessed for depression using DSM-III-R criteria in 1991 and 2012. Additionally, an adapted CES-D-16 scale was used to assess depressive symptoms in 2012. A fitted multi-nominal logistic regression model identified predictors of different trajectories of depression. For the whole group, the rate of clinical depression dropped from 51.5% in 1991 to 31.7% in 2012. Earthquake intensity and experiencing strong fear at baseline were strongly associated with chronic (depressed at both assessments, 18.1%) and recovered (depressed only in 1991, 33.5%) depression trajectories compared with the healthy group, with odds ratios (OR) over 4.0 and 3.0, respectively. Predictors distinguishing chronic depression included earthquake-related nuclear-family deaths (OR=3.79), chronic illnesses at baseline (OR=1.24), and social support (OR=0.91). Predictors of the late-onset trajectory (depressed only in 2012, 13.5% of the cohort) included post-earthquake trauma (OR=1.42), socioeconomic status (OR=0.45), and social support (OR=0.86). The factors associated with the different trajectories of depression provide guidance for planning more effective mental health interventions after disasters.