Although adolescence marks the onset of many risk factors for non-communicable diseases (NCDs)—including cardiovascular diseases, cancers, diabetes, chronic respiratory conditions, and mental disorders—these are often only considered in relation to adult health. There is limited insight into how various NCD risk factors co-occur and how they may influence mental wellbeing during adolescence. This study investigates how common these risks are, how they cluster, and how they are connected to mental wellbeing among adolescents in Indonesia—a nation with a youthful demographic and rising rates of NCDs. The study involved 1,331 adolescents aged 16–18 years from secondary schools in Jakarta (n = 609) and South Sulawesi (n = 722). Risk factors across five key domains—adiposity, physical inactivity, poor diet, substance use, and high levels of sedentary behavior—were assessed using a combination of objective measurements and self-reported data. In Jakarta, additional biomedical indicators such as blood glucose, cholesterol, triglycerides, and blood pressure were also evaluated. Mental wellbeing was measured using three criteria: psychological distress, overall quality of life (QoL), and QoL related to physical function. Multivariable linear regression models were used to examine associations between multiple risk factors and wellbeing outcomes, adjusting for factors such as province, sex, socioeconomic status, and religion. Clustering of NCD risk factors was widespread, with 58.9% (95% CI: 53.7–63.9) of participants showing three or more concurrent risks. Adolescents with at least one NCD risk were more prone to report psychological distress, with this association being strongest among those spending extensive time on sedentary activities like video gaming and computer use. A greater accumulation of risk factors corresponded with reduced psychological wellbeing and lower scores in both overall and physical function QoL. In the Jakarta subgroup, psychological distress was notably linked to elevated blood glucose and reduced HDL levels, while a higher count of physiological risk markers was associated with poorer physical function QoL. Findings indicate that both individual and combined NCD risk factors are strongly associated with lower mental wellbeing in Indonesian adolescents, even when controlling for potential confounders.
