Clinical features of late-onset schizophrenia in Japan: comparison with early-onset cases

Although the fourth edition of the Diagnostic and Statistical Manual of Mental Disorders abandoned the use of the specifier 'late-onset', a considerable number of studies have reported clinical characteristics of late-onset schizophrenia. Still, only limited research has been conducted on late-onset schizophrenia, especially in Asian countries. In this epidemiological study, the clinical characteristics of late-onset schizophrenia were examined in comparison with early-onset schizophrenia.

All patients with schizophrenia admitted to the psychiatric ward of Jichi Medical University Hospital between 1 April 1993 and 31 March 2006 were divided into two groups according to age at first onset: ≥40 years (late-onset group) and <40 years (early-onset group). The sex ratio, presence or absence of depression, schizophrenia subtype, premorbid character, marital history, and employment history at first onset were compared between the two groups.

Of the 316 patients with schizophrenia identified, 38 patients were assigned to the late-onset group and 278 patients to the early-onset group. Mean age at onset was 23.9 ± 8.2 years for all men and 28.0 ± 13.5 years for all women. The late-onset group was characterized by more women, more paranoid type, more depressive symptoms, less introverted premorbid character, better premorbid adaptation and less neuroleptics.

The characteristics of late-onset schizophrenia in Japan are in line those reported previously.