Mental disorders, comorbidities, and suicidality at 30 years of age in a Brazilian birth cohort

Background: Studies on mental disorders prevalence and comorbidity, including suicidality, are scarce in low and middle-income settings. We aimed to describe the pattern of comorbidity between mental disorders and their association with suicidality.

Methods: In 1982, all hospital deliveries in Pelotas (Southern Brazil) were identified (n = 5914) and have been prospectively followed. Participants were evaluated for the presence of common mental disorders (CMD) at the ages of 18-19, 23 and 30 years. In 2012-13 (30 years of age), trained psychologists evaluated 3657 individuals for disorders using the Mini International Neuropsychiatric Interview.

Results: Prevalence of suicidal wishing, suicidal planning and lifetime suicidal attempt was 4.9%, 3.8% and 6.6%, respectively. Suicidal wishing was most strongly associated with having joint major depressive episode (MD) and lifetime suicidal attempt (OR = 26.4, 95%CI:13.9-50.4) with comorbid MD with mania/hypomania (OR = 21.2, 95%CI:6.93-65.1). Suicidal planning was most strongly associated with having joint MD and lifetime suicidal attempt (OR = 44.7, 95%CI:22.6-88.4), with comorbid MD and social anxiety disorder (OR = 30.6, 95%CI:13.0-72.0), and joint social anxiety disorder with lifetime suicidal attempt (OR = 26.3, 95%CI:8.33-82.7). Independently of other disorders, prospective and cross-sectional measures of CMD were associated with higher rates of suicidality.

Limitations: We do not have data on suicide deaths in follow-up and the diagnostic instrument used at 30 years of age was not used in all previous follow-up.

Conclusion: MD and social anxiety have independent and combined associations with suicidality, and also with they occur with lifetime suicidal attempt and other mental disorders.