BackgroundLittle is known about the relationship between adolescent affective problems (anxiety and depression) and mortality.AimsTo examine whether adolescent affective symptoms are associated with premature mortality, and to assess whether this relationship is independent of other developmental factors.MethodData (n= 3884) was from Britain's oldest birth cohort study – the National Survey of Health and Development. Adolescent affective symptoms were rated by teachers at ages 13 and 15 years: scores were summed and classified into three categories: mild or no, moderate and severe symptoms (1st–50th, 51st–90th and 91st–100th percentiles, respectively). Mortality data were obtained from national registry data up to age 68 years. Potential confounders were parental social class, childhood cognition and illness, and adolescent externalising behaviour.ResultsOver the 53-year follow-up period, 12.2% (n= 472) of study members died. Severe adolescent affective symptoms were associated with an increased rate of mortality compared with those with mild or no symptoms (gender adjusted hazard ratio 1.76, 95% CI 1.33–2.33). This association was only partially attenuated after adjustment for potential confounders (fully adjusted hazard ratio 1.61, 95% CI 1.20–2.15). There was suggestive evidence of an association across multiple causes of death. Moderate symptoms were not associated with mortality.ConclusionsSevere adolescent affective symptoms are associated with an increased rate of premature mortality over a 53-year follow-up period, independent of potential confounders. These findings underscore the importance of early mental health interventions.Declaration of interestNone.