[Exposure to breastfeeding and common mental disorders in adolescence].

This article sought to evaluate the effect of exposure, and exposure time, to breastfeeding on the occurrence of common mental disorders (CMD) among Brazilian adolescents enrolled in school. This study analyzed data from the Study of Cardiovascular Risk in Adolescents (ERICA), evaluating those whose questionnaire regarding breastfeeding had been filled out by parents or guardians. The presence of CMD was identified using the General Health Questionnaire, version 12 items (GHQ-12), and we considered two cutoff points (scores ≥ 3 and ≥ 5). We tested the associations in bivariate analyses and through multiple logistical regression models, adjusting for potential confounding variables. Of the 41,723 adolescents we evaluated, most were students of the female sex (54.6%), aged between 12 and 15 years (71%), attended public schools (83.1%), resided in the Southeastern region (51.9%) and belonged to the economic classes B (53.8%) and C (34.1%). Around half of the adolescents' mothers had not completed their secondary education (51.7%). The group of adolescents who were breastfed for more than six months (51.8%) had a lower CMD prevalence for both GHQ-12 cutoff points, when compared with the group who were not breastfed or who were breastfed for ≤ 1 month (IR = 0.82; 95%CI: 0.69-0.97 and IR = 0.74; 95%CI: 0.59-0.91 for 3 and 5 points, respectively). Prolonged breastfeeding seems to play a protective role on the occurrence of CMD in adolescence.