Background: Gender differences in the clinical presentation of young patients with schizophrenia have been well-documented, yet few studies have investigated gender-related clinical differences in older patients. Furthermore, the symptoms of late-onset schizophrenia have been described, but the interaction between gender and age at onset has not been examined.
Method: In an older (46-85 years of age) outpatient sample, we assessed clinical characteristics of women and men with early-onset schizophrenia (N = 90) and late-onset schizophrenia (N = 34). Subjects did not differ with respect to age, education, ethnicity, severity of depression, daily neuroleptic dosage, subtype of schizophrenia, total score on the Mini-Mental State Examination, or severity of overall psychopathology. Diagnosis was made using the Structured Clinical Interview for the DSM-III-R or DSM-IV.
Results: A significantly greater proportion of women had late-onset schizophrenia (41% vs. 20%), and women overall had more severe positive psychotic symptoms. Although there was no overall gender difference in severity of negative psychotic symptoms, women with late onset had significantly less severe negative symptoms than men with early onset, men with late onset, and women with early onset. Furthermore, age at onset of schizophrenia was inversely correlated with severity of negative symptoms for women, but not for men. These results indicate that women overall may develop more severe positive symptoms than men, and that when women develop schizophrenia after age 45, they may suffer less severe negative symptoms than men or than women with earlier onset. Our results suggest that some of the clinical differences between late-onset and early-onset schizophrenia may relate to gender effects, and that there may be inherent differences in the clinical presentation of schizophrenia that are related to gender and gender by age at onset interactions.
Conclusion: These differences may reflect the influence of sex hormones and menopause on the clinical presentation of schizophrenia or the possible existence of an "estrogen-related" form of schizophrenia in women with late-onset schizophrenia.