Risk of depressive disorder following disasters and military deployment: systematic review with meta-analysis

Numerous studies describe the occurrence of post-traumatic stress disorder following disasters, but less is known about the risk of major depression. To review the risk of depressive disorder in people surviving disasters and in soldiers returning from military deployment. A systematic literature search combined with reference screening identified 23 controlled epidemiological studies. We used random effects models to compute pooled odds ratios (ORs). The average OR was significantly elevated following all types of exposures: natural disaster OR = 2.28 (95% CI 1.30-3.98), technological disaster OR = 1.44 (95% CI 1.21-1.70), terrorist acts OR = 1.80 (95% CI 1.38-2.34) and military combat OR = 1.60 (95% CI 1.09-2.35). In a subset of ten high-quality studies OR was 1.41 (95% CI 1.06-1.87). Disasters and combat experience substantially increase the risk of depression. Whether psychological trauma per se or bereavement is on the causal path is unresolved.