Psychiatric sequelae in atomic bomb survivors in Hiroshima and Nagasaki two decades after the explosions

Atomic bomb exposure was an extraordinarily stressful event. Although little epidemiological research has been performed on the psychiatric effects of the bombings, many medical descriptions of the survivors suggest that there was an increase of various symptoms that implied autonomic ataxia or neurosis-like disorders. The psychiatric effects of exposure to the atomic bomb explosions in Hiroshima and Nagasaki were assessed in this study.

From a self-administered medical questionnaire completed between 1962 and 1965 by 9421 informed and consenting Adult Health Study subjects, some questions congruent with the DSM-IV diagnostic criteria for generalized anxiety disorder and somatization disorder were selected and used as indicators of anxiety symptoms and somatization symptoms. The prevalence of psychiatric symptoms in relation to age, sex, city (Hiroshima vs. Nagasaki), acute radiation symptoms, exposure status (in city or not in city), ground distance from hypocenter, disease history, and death of family members were analyzed.

A higher prevalence of anxiety symptoms (odds ratio, 1.73) and somatization symptoms (odds ratio, 1.99) was observed in those with acute radiation symptoms than in those without them. The prevalence of anxiety symptoms and somatization symptoms among people who were in the city at the time of the explosion was significantly higher than among those who were not in the city. Among the former, prevalence was lower among proximally exposed people than among distally exposed people. Symptom prevalences were also affected by age, sex, and city. Although disease history such as neurotic disorder and ulcer were risk factors for anxiety symptoms and somatization symptoms, the increased prevalence of anxiety symptoms and somatization symptoms in association with atomic bomb exposure was independent of disease history and the death of family members.

The prevalence of anxiety symptoms and somatization symptoms was elevated in atomic bomb survivors even 17-20 years after the bombings had occurred, indicating the long-term nature of the psychiatric effects of the experience. Psychiatric sequelae were independent of physical sequelae.