Perinatal anxiety disorder prevalence and incidence

Anxiety and related disorders (AD) disproportionately affect women, and are the most prevalent of all mental health conditions. The current research represents the first study of maternal postpartum AD prevalence in which all of the AD are assessed, and one of few studies of this type in which maternal prenatal AD incidence is assessed.

A Canadian sample of pregnant women (N=310) was recruited from a defined geographical area between November 2007 and November 2010. Participants were first administered postnatal mood and anxiety screening measures. Those who scored at or above cutoff on one or more of these measures were administered a diagnostic interview for depression and anxiety at approximately three months postpartum (n=115). Findings from the diagnostic interview were used to estimate the prevalence and incidence of mood and AD in pregnancy, as well as at and during the first three months postpartum. Period prevalence and incidence estimates were obtained retrospectively from interview data collected postnatally.

The prevalence of AD during pregnancy and the early postpartum period (15.8% and 17.1% respectively) exceeded that of depression (3.9% and 4.8% respectively). The prevalence of OCD in our sample exceeded that of OCD among adults aged 18-64. Parity was unrelated to AD prevalence. Slightly less than 5% of participants were comorbid for both AD, and depression.

This study is limited by a relatively small sample size for a prevalence study, and non-random sample selection. As only women who scored above cutoff on one or more screening measures were interviewed, prevalence estimates are conservative. Finally, prenatal prevalence estimates are based on retrospective report provided postpartum.

This study provides evidence that, as a group, anxiety and related conditions affect a significant proportion of postpartum women, and are more prevalent than is postpartum depression.