Brown HK, et al. - Researchers examined how chronic physical conditions are associated with the risk of perinatal mental illness. In this population-based retrospective cohort study performed using linked health administrative data sets in Ontario, Canada, 77,385 women with chronic physical conditions were compared with 780,619 women without such conditions regarding their risks of a psychotic disorder, mood or anxiety disorder, substance use disorder, self-harm, or another mental illness arising in pregnancy or within 365 days of childbirth. Perinatal mental illness was experienced by more women with (20.4%) than without (15.6%) a chronic physical condition. Women with vs without chronic physical conditions displayed a higher likelihood for psychotic disorders, mood or anxiety disorders, substance use disorders, and other mental illness, but not for self-harm. They noted large consistency in this risk across the timing and specific diagnosis of perinatal mental illness as well as the type of chronic physical condition.