Patterns and Predictors of Trajectories of Depression after an Urban Disaster

Received 2 June 2009; accepted 25 June 2009. published online 25 August 2009.

Purpose

To identify and understand the patterns and predictors of depressive symptom trajectories over time after mass traumatic events.

Methods

Data were used from a prospective, representative sample of adult residents of the New York City metropolitan area (N=2,282) followed up across four survey waves between 2001 (after the September 11 attacks) and 2004. Semi-parametric group-based modeling was used to identify trajectories, as well as the time-fixed and time-varying predictors of distinct depressive trajectories.

Results

Five distinct trajectories of depression were characterized: minimal symptomatology at all time points (group 1, 39% of sample), mild delayed depression (group 2, 34% of sample), recovery (group 3, 6% of sample), severe delayed depression (group 4, 13% of sample), and chronic severe depression (group 5, 8% of sample). Among members of distinct trajectories, lower household income, exposure to ongoing stressors, and exposure to traumatic events were commonly associated with an increased number of depressive symptoms.

Conclusions

Ongoing socioeconomic adversity appears to be centrally associated with a worse course of depression after exposure to traumatic events. Identifying distinct trajectories of depression and the preventable factors that are associated with them may facilitate the development of interventions that aim to promote better mental health.

Key Words: Depression, Mental Disorders, Disasters

Selected Abbreviations and Acronyms: BSI, Brief Symptom Inventory, DSM-IV, Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, NYC, New York City, SCID, Structured Clinical Interview for Diagnostic and Statistical Manual of Mental Disorders, Third Edition Revised

a Center for Population and Development Studies; Harvard School of Public Health; Boston, MA

b Department of Epidemiology, University of Michigan School of Public Health, Ann Arbor, MI

c Survey Research Center, Institute for Social Research, Ann Arbor, MI

d Center for Urban Epidemiologic Studies, New York Academy of Medicine, New York, NY

e Department of Epidemiology, Columbia University Mailman School of Public Health, New York, NY

f School of Public Health, University of Sydney; Sydney, Australia

g Faculty of Health and Applied Science, Southern Cross University, Lismore, NSW, Australia

Address correspondence to: Sandro Galea, MD, DrPH, Professor, Department of Epidemiology, University of Michigan, School of Public Health, 109 Observatory St, Room 3663, Ann Arbor, MI 48109-2029. Tel: (734) 647-9741. fax: (734) 763-5706.

PII: S1047-2797(09)00178-1

doi:10.1016/j.annepidem.2009.06.005

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