Where Are the Women in First-Episode Studies of Schizophrenia?

Abstract

Almost all investigations of first-episode schizophrenia uncover more male than female subjects. Two possible explanations for this observation are (1) first-episode investigations suffer more or less consistent methodologic biases or (2) the incidence of schizophrenia is higher in men than in women. Data from the markers and predictors of schizophrenia (MAP) project, a community-based first-episode study, permitted an investigation of the two alternatives. The results suggest that neither recruitment nor diagnostic vagaries explain the excess of males. Instead, the MAP results, consistent with other recent investigations, suggest that the incidence of schizophrenia is lower in women than in men. The findings are consistent with the literature on gender differences in schizophrenia, which indicates that schizophrenia in women is a less severe disorder than in men. The report includes recommendations for future first-episode investigations to ensure adequate representation of women.

Study the rate of fertility and risk factors of schizophrenia in Najaf, Iraq

“…Schizophrenia is more common in male than female as in Figure 2, this result is quite similar to the findings of [11] who supposed that schizophrenia occurred about twice as higher for male than female regardless of the specific diagnostic criteria which is used for this purpose. The positive association of smoking with schizophrenia, which was recorded in Table 1 is supported by [12] who elucidated that the rate of smoking among schizophrenia patients could be increased when to compare with control.…”

Genome-wide scan in a large complex pedigree with predominantly male schizophrenics from the island of Kosrae: evidence for linkage to chromosome 2q

“…43,65 However, no significant differences in disease rates between sexes have been described, 66,67 although more recent, community-based first-episode studies suggest a two-fold increased incidence for men. 68 The observed male predominance in Kosrae cannot be accounted for by either population statistics (male to female ratio in the 1994 census was 1.08 : 1.00), or by our sample statistics (59% male subjects, 41% female sujbects). It is possible that mental illness is under-recognized in females in Micronesia because of some form of cultural bias, but this is not supported by previous reports about schizophrenia in that part of the world.…”

Contrasting Effects of Increased and Decreased Dopamine Transmission on Latent Inhibition in Ovariectomized Rats and Their Modulation by 17β-Estradiol: An Animal Model of Menopausal Psychosis?

“…Women have a more favorable illness course during the reproductive years, characterized by later onset of symptoms, lower symptom severity, and better response to antipsychotic drug (APD) treatment (Agius et al, 2009;Angermeyer and Kuhn, 1988;Hafner, 2003;Hafner et al, 1989;Iacono and Beiser, 1992;Lindamer et al, 1997;Mortimer, 2007;Pregelj, 2009;Riecher-Rossler and Hafner, 2000;Salem and Kring, 1998;Seeman, 1982Seeman, , 1986Szymanski et al, 1995;Tamminga, 1997). In contrast, menopause is associated with increased vulnerability to illness, elevated symptom severity, and reduced response to treatment (Horacek et al, 2006;Kulkarni et al, 1996Kulkarni et al, , 2008bLane et al, 1999;Salokangas, 1995;Saugstad, 1989;Seeman and Lang, 1990).…”