Objective: The aim of this study was to examine the relationship between prenatal exposure to atomic bomb (A-bomb) radiation and the development of schizophrenia in adulthood.
Method: We investigated the lifetime prevalence of schizophrenia among people prenatally exposed to the 1945 Nagasaki A-bomb, using the schizophrenia register and the A-bomb survivors' database.
Results: Among 1867 prenatally exposed individuals, 18 subjects (0.96%) had developed schizophrenia later in life. The prevalence was significantly higher in people exposed in the second trimester of pregnancy than in those exposed in the third trimester. The closer they had been to the hypocentre, the higher was the prevalence, but no statistically significant linear relationship was seen.
Conclusion: This investigation could not clarify the nature of exposure to A-bomb radiation as a risk factor for schizophrenia in the prenatal period.