Epidemiology of Mental Disorders

This review describes the contribution of psychiatric epidemiology to our understanding of the distribution and determinants of psychiatric disorders. First, it describes basic concepts within epidemiology, such as prevalence, incidence, case definition, bias, and confounding, and their specific meaning within psychiatric research. The two basic study designs in epidemiology, cohort and case-control, are then reviewed. This discussion includes a tutorial on how to calculate key measures of association: risk ratio and odds ratio. Major community-based studies in psychiatric epidemiology are then reviewed, focusing on the Epidemiologic Catchment Area Study, the National Comorbidity Study and the National Comorbidity Study Replication, the National Survey of American Life, the National Latino and Asian American Study of Mental Health, and the National Epidemiologic Survey on Alcohol and Related Conditions. The review concludes with a discussion of pharmacoepidemiology and how it is critical to our understanding of the full impact of psychiatric medications postmarketing. In the future, epidemiology will be revolutionized with “big data” collection in both institutional and community settings. Nonetheless, the basic concepts presented in this review will continue to be relevant and critical to drawing sound, evidence-based conclusions about the true nature, correlates, and causes of psychiatric disorders. This review contains 6 tables, and 63 references. Key words: case-control study, cohort study, community-based studies, measures of association, pharmacoepidemiology, psychiatric epidemiology

Associations of depression status and hopelessness with breast cancer: A 24-year follow-up study

This study extended the literature by examining whether three profiles of depression predicted breast cancer status. In 1076 women of the Baltimore Epidemiologic Catchment Area study, depression status and hopelessness were measured at baseline and breast cancer status was ascertained 24 years later. Double depression, but not major depression or dysthymia, was associated with breast cancer. Hopelessness predicted fewer new cases of breast cancer. When double depression and hopelessness were simultaneously entered as predictors, the regression weights of both predictors increased. The role of severe and extended duration depression as well as possible explanations for unexpected findings are discussed.

Psychotic experiences and risk of death in the general population: 24–27 year follow-up of the Epidemiologic Catchment Area study

BackgroundPsychotic experiences are common in the general population and are associated with adverse psychiatric and social outcomes, even in the absence of a psychotic disorder.AimsTo examine the association between psychotic experiences and mortality over a 24–27 year period.MethodWe used data on 15 049 adult participants from four sites of the Epidemiologic Catchment Area baseline survey in the USA in the early 1980s, linked to the National Death Index and other sources of vital status up until 2007. Psychotic experiences were assessed by the Diagnostic Interview Schedule.ResultsLifetime psychotic experiences at baseline (n = 855; weighted prevalence, 5.5%) were significantly associated with all-cause mortality at follow-up after adjustment for sociodemographic characteristics and psychiatric diagnoses, including schizophrenia spectrum disorders (P<0.05). Baseline psychotic experiences were associated with over 5 years' shorter median survival time. Among the underlying causes of death, suicide had a particularly high hazard ratio (9.16, 95% CI 3.19–26.29).ConclusionsFuture research needs to explore the association of psychotic experiences with physical health and lifestyle factors that may mediate the relationship of psychotic experiences with mortality.