The Symptom Structure of Postdisaster Major Depression: Convergence of Evidence from 11 Disaster Studies Using Consistent Methods

Abstract

Background: Agreement has not been achieved across symptom factor studies of major depressive disorder, and no studies have investigated depressive symptom structures in disaster-exposed samples. This study examined the symptom structure of major depression across two databases of 1,181 total survivors from 11 disasters studied using consistent research methods and full diagnostic assessment, addressing limitations of prior symptom scale studies. Methods: The sample included 808 directly-exposed survivors of 10 different disasters assessed 1-6 months of the disasters and 373 employees of 8 New York City organizations affected by the September 11, 2001 (9/11) terrorist attacks 3 years after the attacks. Depressive symptom profiles were compared across the two databases to determine the consistency of findings across different disasters and settings. Outcomes: Consistent symptom patterns predicting postdisaster major depression were not identified across the 10-disaster and 9/11 databases, and both database factor analyses suggested cohesive grouping of all 9 depression symptoms without separation into subgroups of symptoms clustering together. The 10-disaster and 9/11 databases identified different symptoms predicting postdisaster major depression. Interpretation: These findings do not suggest a starting point for identification of a subsample of symptoms that can be used to indicate the presence of major depression following a disaster or evidence to guide the construction and validation of a screening instrument for postdisaster major depression. This study surmounted prior methodologic challenges and provided initial findings to inform further studies needed to identify depressive symptom patterns and factors that can be used to improve detection and treatment of major depressive disorder. Funding Statement: This work was supported by the National Institute of Mental Health (Grants MH40025, MH68853, and MH094822). Declaration of Interests: The authors declare no conflicts of interest. Ethics Approval Statement: Advance approval for the research was obtained from the Institutional Review Boards of the participating research institutions, and all members of the study sample provided written informed consent for participation.