This paper examined whether distinct life-course trajectories of psychological distress from adolescence to midlife were associated with poorer mental health outcomes during the pandemic.

We present a secondary analysis of two nationally representative British birth cohorts, the 1958 National Child Development Study (NCDS) and 1970 British Cohort Study (BCS70). We used latent variable mixture models to identify pre-pandemic longitudinal trajectories of psychological distress and a modified Poisson model with robust standard errors to estimate associations with psychological distress, life satisfaction and loneliness at different points during the pandemic.

Our analysis identified five distinct pre-pandemic trajectories of psychological distress in both cohorts. All trajectories with prior symptoms of psychological distress irrespective of age of onset, severity and chronicity were associated with a greater relative risk of poorer mental health outcomes during the pandemic and the probability of poorer mental health associated with psychological distress trajectories remained fairly constant. The relationship was not fully attenuated when most recent pre-pandemic psychological distress and other midlife factors were controlled for.

Whilst life-course trajectories with any prior symptoms of psychological distress put individuals at greater risk of poor mental health outcomes during the pandemic, those with chronic and more recent occurrences were at highest risk. In addition, prior poor mental health during the adult life-course may mean individuals are less resilient to shocks, such as pandemics. Our findings show the importance of considering heterogeneous mental health trajectories across the life-course in the general population in addition to population average trends.

Adolescent mental health difficulties are increasing over time. However, it is not known whether their adulthood health and socio-economic sequelae are changing over time.

Participants (N = 31 349) are from two prospective national birth cohort studies: 1958 National Child Development Study (n = 16 091) and the 1970 British Cohort Study (n = 15 258). Adolescent mental health was operationalised both as traditional internalising and externalising factors and a hierarchical bi-factor. Associations between adolescent psychopathology and age 42 health and wellbeing (mental health, general health, life satisfaction), social (cohabitation, voting behaviour) and economic (education and employment) outcomes are estimated using linear and logistic multivariable regressions across cohorts, controlling for a wide range of early life potential confounding factors.

The prevalence of adolescent mental health difficulties increased and their associations with midlife health, wellbeing, social and economic outcomes became more severe or remained similar between those born in 1958 and 1970. For instance, a stronger association with adolescent mental health difficulties was found for those born in 1970 for midlife psychological distress [odds ratio (OR) 1970 = 1.82 (1.65–1.99), OR 1958 = 1.60 (1.43–1.79)], cohabitation [OR 1970 = 0.64 (0.59–0.70), OR 1958 = 0.79 (0.72–0.87)], and professional occupations [OR 1970 = 0.75 (0.67–0.84), OR 1958 = 1.05 (0.88–1.24)]. The associations of externalising symptoms with later outcomes were mainly explained by their shared variance with internalising symptoms.

The widening of mental health-based inequalities in midlife outcomes further supports the need to recognise that secular increases in adolescent mental health symptoms is a public health challenge with measurable negative consequences through the life-course. Increased public health efforts to minimise adverse outcomes are needed.

Previous results have been mixed regarding the role of the apolipoprotein E e4 (APOE e4) allele in later-life depression: some studies note that carriers experience greater symptoms and increased risk while others find no such association. However, there are few prospective, population-based studies of the APOE e4-depression association and fewer that examine depressive symptom trajectory and depression risk longitudinally. We examined the association between APOE e4 allele status and longitudinal change in depressive symptoms and depression risk in later-life, over a 12-year follow-up period.

We used data from 690 participants of the Lothian Birth Cohort 1936 who took part in the Scottish Mental Survey 1947 (aged 11) and were followed-up in later-life over five waves from 2004 to 2019 (aged 70–82). We used APOE e4 allele status to predict longitudinal change in depressive symptom scores and risk of depression (defined by a symptom score threshold or use of depression-related medication). Models were adjusted for sex, childhood cognitive ability, childhood social class, education, adult social class, smoking status and functional limitations at baseline.

Depressive symptom scores increased with age. Once adjusted for covariates, APOE e4 allele status did not significantly predict symptom score trajectories or depression risk. Greater functional limitations at baseline significantly predicted poorer symptom score trajectories and increased depression risk (defined by medications). APOE e4 allele status did not significantly moderate the contribution of sex, education or functional limitations.

There was no evidence that APOE e4 carriers experience an increased risk for later-life depression.