Trajectory and Socioeconomic Predictors of Depression in a Prospective Study of Residents of New York City

Purpose Past research has demonstrated the high prevalence of depression in the general population. However, few longitudinal studies have characterized the patterns of depression in a large, representative sample of the general population. We monitored symptoms of depression and assessed the factors associated with changing symptoms of depression in a population-based cohort over a 30 month period. Methods Using telephone surveys, we recruited 2752 adult residents of New York City in 2002. Persons were re-contacted after baseline for telephone interviews at 6 months, 18 months, and 30 months. Results Among study participants, symptoms of depression were common, often resolved within 6 months, but tended to recur. Participants with a past history of depressive symptoms were more at risk of later developing depression, even if they were asymptomatic at baseline. Factors significantly associated with subsequent symptoms included less social support at baseline, income below a threshold of $50,000, life stressors, poor health, and being separated. Lower levels of social support and lifetime stressors were only significantly associated with symptoms in participants with multiple episodes of depression. The influence of recent stressful events was also higher among participants with multiple episodes of depression. Conclusion In the general population depression has a good immediate prognosis but a recurring nature. Poor physical health and low levels of social support appear to increase the risk of later episodes of depression. The influence of social risk factors may be greater for persons with higher susceptibility to depression.