Childhood emotional symptom trajectories in three generationally and socio-ethnically distinct UK birth cohorts

Background: Depression and anxiety symptoms emerge early in life. We examined developmental trajectories of emotional symptoms, starting from early childhood, in three UK birth-cohorts spanning successive generations and diverse socio-ethnic contexts. Methods: Using data from three longitudinal, population-based UK birth-cohorts: Avon Longitudinal Study of Parents and Children (ALSPAC), Millenium Cohort Study (MCS), and Born in Bradford (BiB) we identified group-based trajectories of emotional symptoms using repeated Strengths and Difficulties Questionnaire, Emotional Subscale (SDQ-E) scores from ages 3-14y. Baseline samples comprised children with [≥]1 SDQ-E measure between age 3-14y (NALSPAC=11,025; NMCS=15,446; NBiB=6711). Participants were born three decades apart (ALSPAC: 1990-2, MCS: 2000-2, BiB: 2007-10) in distinct socioeconomic and ethnic contexts. We characterised group membership by: female sex, non-white ethnicity, maternal depression/anxiety and IMD quintile. In ALSPAC we modelled associations between trajectories and depression/anxiety diagnoses in early adulthood (24y and 30y). Results: In all cohorts 49% were female. ALSPAC had few non-white participants (4%) compared to MCS (17%) and BiB (66%). Each cohort had low-, mid- and high-level symptom trajectories. High-level trajectories comprised 6-7% of the population in each cohort. However, in younger cohorts, high-level symptom trajectories started high and persisted from age 3-5y but started low and increased in the oldest cohort. Female sex and maternal depression/anxiety were associated with higher odds of high-level or increasing symptom trajectories across all cohorts. Higher socioeconomic status and belonging to the ethnic majority was protective. Mid- and high-level symptom trajectories had higher odds of depression/anxiety diagnoses in early-adulthood in the older ALSPAC cohort. Conclusions: Developmental trajectories of emotional symptoms across childhood and adolescence are broadly similar across generations and diverse social contexts. However, children born more recently and in more diverse contexts may experience more persistent, severe emotional symptoms from a young age Key words: Longitudinal trajectories; emotional symptoms; SDQ, ALSPAC; MCS; Born in Bradford