Estimation of the future numbers of patients with mental disorders in Japan based on the results of National Patient Surveys.

To estimate the future numbers of patients with mental disorders, schizophrenic disorders, and neurotic disorders, prevalence obtained from the National Patient Surveys conducted by the Ministry of Health and Welfare of the Japanese government was projected by using linear models by age and sex. The prevalence of whole mental disorders and neurotic disorders will increase, while that of schizophrenic disorders will not do so much. The numbers of patients with mental disorders were estimated to be 973 thousand for males and 1,359 thousands for females in the year of 2008, which were 622 thousand and 733 thousand in 1993, respectively. The disease-specific numbers in 2008 were 562 thousand for schizophrenic disorders and 867 thousand for neurotic disorders, both were 451 and 437 thousand in 1993, respectively. Because of the increase of old age population, the number of old patients with each disorder will also become large.