Post-natal depression in an urban area of Portugal: comparison of childbearing women and matched controls.

The point prevalence of depression measured on one occasion between 2 and 5 months after childbirth was estimated to be 13.1% in 352 mothers living in urban Portugal; the criterion was a score of 13 or more on a translated version of the Edinburgh Post-natal Depression Scale (EPDS). More detailed comparisons were made between a subgroup of 118 mothers and 118 matched controls who had not borne a child in the previous 2 years. Post-natal women were twice as likely as non-childbearing controls to meet the EPDS criterion for depression In comparison with controls, they were also more severely depressed as judged by their total scores on another questionnaire, the Zung Scale. Comparisons of individual symptom scores (Zung Scale) showed that childbearing women, as a whole, reported more somatic symptoms than controls, but when only those women judged to be depressed or dysphoric by the EPDS were compared, this difference disappeared. Stepwise logistic analyses of symptoms contributing to the categorization of a 'case' of post-natal versus non-post- natal depression did not reveal any very clear divergences in self-reported psychopathology. In childbearing women, two factors were found significantly to contribute to higher depression scores; women with more children and those from lower socio-economic groups were most at risk.