There is a well-established association between gender and the prevalence of mental illness. The objective of this study was to determine whether gender also influences the timing of remission from illness. The regression analysis undertaken considered remission in terms of all ICD-9 mental disorders (codes 290-314). This analysis compares males and females on average length of treatment for mental illness and examines whether any gender differences in remission are generalized or disorder specific.
The statistical analysis was based on longitudinal (1990-2001) administrative data on 5,118 females and 2,470 males. The target population represented all individuals with an ICD-9 diagnosis of mental illness who were treated through the Medical Services Plan in British Columbia. The regression analysis used the generalized estimating equations method to model differences in length of treatment.
There was a non-significant bivariate relation between gender and the timing of remission from mental illness. However, the multivariate findings demonstrated that a significant gender effect on remission emerges after controls were introduced for demographic and socio-economic characteristics. In particular, the timing of remission was somewhat longer for females. This effect was generalized and not restricted to specific illnesses.
The emergence of a significant effect after considering demographic and socio-economic characteristics suggests that a social disadvantage within the male sample (more single males) was suppressing a small negative effect of female gender on the timing of remission. In other words, a social disadvantage among males concealed an unexplained female disadvantage in remission.