Prediction of major depression in Japanese adults: somatic manifestation of depression in annual health examinations.

BACKGROUND: The present study examined whether somatic symptoms found in annual health examinations, could be predictive of major depression in the ensuing year.
METHOD: Subjects analyzed were 1027 non-major-depressive workers (706 men, mean age 35) attending annual health examinations at a research institute. All were Japanese and found not to be suffering from major depression when interviewed, according to the semi-structured interviews of the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition (DSM-IV). A self-administered questionnaire containing items relating to twelve major somatic symptoms was completed by all the subjects. The same DSM-IV interviews for the diagnosis of major depression were conducted to calculate the odds ratio of baseline variables for depressive and somatic symptoms, physical examination items, and health-related life-styles for the prediction of major depression in the ensuing year.
RESULTS: The prevalence of major depression in the ensuing year was 2.5%. For four somatic symptoms (fatigue, lower back pain, dizziness, and nausea), the prevalence was higher (all p < 0.05) in those who complained of each somatic symptom at baseline than in those who did not. Furthermore, the multiple logistic regression analysis indicated that lower back pain and dizziness at baseline were independent risk factors of major depression in the ensuing year [odds ratio (95% confidence intervals), 3.2 (1.1, 8.9) and 6.0 (1.8, 20.1), respectively]. LIMITATIONS: It is possible that somatic manifestations of depression are culturally bound phenomena and results might be generalizable only to Japanese workers.
CONCLUSION: Somatic symptoms reported at annual health examinations may be useful indicators for predicting major depression.