Significant Gender Differences Found in Psychosis Outcome

Women with schizophrenia fare better than do men with the illness, various retrospective studies have found. Now a longitudinal investigation further supports these results.

The study was headed by Linda Grossman, Ph.D., a professor of psychology in the Department of Psychiatry at the University of Illinois at Chicago. Grossman reported the results at APA's 2006 annual meeting in Toronto in May. The results are also published in the June Psychiatric Services.

Grossman and her colleagues recruited 239 young adults, average age 23 years, who were hospitalized for a psychiatric illness. Of the 239 subjects, 69 had schizophrenia, 56 had other types of psychosis, and 114 had nonpsychotic illnesses (notably depression, bipolar disorder, a substance use disorder, an eating disorder, or a personality disorder).

All of the subjects were originally evaluated during hospitalization and then at five follow-up points—two, five, eight, 10, and 15 years—for illness course and recovery. Recovery was defined as the absence of major symptoms and evidence of adequate psychosocial functioning, including working half time or more in the year before each follow-up. The assessment tools included a standardized battery of semistructured interviews, questionnaires, and psychological tests.

Grossman and her group then compared outcomes for the three subject groups, classified by gender, considering age at illness onset, antipsychotic medication use, and other possibly confounding factors. Controlling for age of onset was especially crucial, they explained in their study report,“ because older age before a first psychotic break allows time for development of greater knowledge, social skills, and experience. In addition, older age at first break may suggest greater internal resiliency.”

Gender differences in outcome were found for patients with schizophrenia and for those with other psychotic disorders, with women consistently showing better functioning over time, more periods of recovery, and fewer and shorter rehospitalizations. In other words, while the analyses did not produce uniformly significant results in each area at each follow-up, many gender differences were significant, and all analyses showed that the men's outcome was poorer than the women's.

In contrast, there were no significant gender differences in outcome among subjects with psychiatric illnesses other than psychosis.

Thus, women seem to have an edge when it comes to combating schizophrenia or other psychotic illnesses, yet this advantage does not appear to extend to coping with nonpsychotic conditions, Grossman and her group concluded.

Why this might be the case is not known. However, they proposed several possible explanations for why being female might help combat psychosis. For example, more women with schizophrenia marry than men with schizophrenia do, and having a partner might help them cope with serious mental illness. Women with schizophrenia are less likely to abuse substances than are men with schizophrenia, and lack of substance abuse in turn may speed healing and recovery. Female hormones may likewise boost women's ability to cope with psychosis. Psychopathology has been shown to improve when estrogen levels rise, and vice versa. In fact, it is conceivable that estrogen inhibits postsynaptic dopamine transmission and thereby serves as a“ natural” antipsychotic.

In any event, it appears that being female is not enough to counter psychosis in all instances. The outcome differences between women and men with schizophrenia were found to be only moderate, rather than very large, and only a small number of women with schizophrenia demonstrated complete recovery at all five follow-up points.

The study was funded by the National Institute of Mental Health.

“Sex Differences in Outcome and Recovery for Schizophrenia and Other Psychotic and Nonpsychotic Disorders” is posted at<http://ps.psychiatryonline.org> under the June issue. ▪