Estimated prevalence of perinatal depression (vertical bar chart): 1st trimester: major or minor, 11.0%; major, 3.8%. 2nd trimester: major or minor, 8.5%; major, 4.9%. 3rd trimester: major or minor, 8.5%; major, 3.1%. 1 month postpartum: major or minor, 9.7%; major, 3.8%. 2 months postpartum: major or minor, 10.6%; major, 5.7%. 3 months postpartum: major or minor, 12.9%; major, 4.7%. 1 year postpartum: major or minor, 6.5%; major, 3.9%.

Source: Gaynes BN, Gavin N, Meltzer-Brody S, Lohr KN, Swinson T, Gartlehner G, Brody S, Miller WC. Perinatal depression: prevalence, screening accuracy, and screening outcomes. Evidence Report/Technology Assessment No. 119. Rockville, MD: Agency for Healthcare Research and Quality. January 2005.