Early age of onset of mood, anxiety and alcohol use disorders is associated with sociodemographic characteristics and health outcomes in adults: results from a cross-sectional national survey

Purpose This cross-sectional study investigated distribution, sociodemographic correlates, and health outcomes in early versus late age of onset (AOO) of mood, anxiety, and alcohol use disorders in Singapore. Methods The Composite International Diagnostic Interview established lifetime diagnoses of major depressive, bipolar, generalized anxiety, obsessive compulsive and alcohol use disorders in a representative sample of residents aged 18 years and over ( n = 6126). The AOO of the individual and any mental disorders were classified into early and late onset using median values as cut-offs. Data included socio-demographic and health background, health utility score, and productivity losses. Multivariable logistic regression analysis was conducted to assess sociodemographic correlates of early versus late AOO of any mental disorder while linear regression analysis investigated the associations between AOO of individual disorders with health utility score and productivity loss. Results Respondents’ mean (SD) age was 45.6 (16.5) years, comprising 50.5% women and majority of Chinese ethnicity (75.8%). The median AOO for any of the five studied disorders was 21 years (IQR: 15–29). Lowest AOO was observed for obsessive compulsive disorder (Median: 14, IQR: 11–26). Those aged 35 years and over (versus 18–34) were less likely to have earlier AOO [35–49 years (OR: 0.287; 95% CI: 0.154–0.534); 50–64 years (OR:0.156; 95% CI: 0.068–0.361) and 65 and over (OR:0.112; 95% CI:0.027–0.461)], while Malay ethnicity (versus Chinese) (OR: 2.319; 95% CI: 1.384–3.885) and being never married (versus married) (OR: 2.731; 95% CI: 1.493–4.993) were more likely to have early AOO for any mental disorder. Sample with early (versus late) AOO had a lower health utility score ( β = − 0.06,95% CI: − 0.08 to − 0.03) and higher number of days cut down on the type of work ( β = 1.61,95% CI: 0.12–3.10) in those with any mental disorders. Conclusion This study showed that half of the adults with mood, anxiety or alcohol use disorders in Singapore experienced their illness onset by 21 years of age. Early AOO is associated with sociodemographic background and poor health outcomes. Prevention, early detection, and interventions to improve health outcomes in mental disorders should consider the sociodemographic profile and age at first onset of symptoms in the population.