Strengths and weaknesses
The main strength of our study is the availability of data from five cohorts, allowing us to explore the effect of a range of potential risk factors from both early and later life on risk of symptoms of depression or anxiety in older people. It also has some weaknesses. First, the majority of our analyses were based on cross-sectional data, making it hard to establish the direction of effect for some associations. Second, the prevalence of ‘probable ’ depression – HADS depression subscale (HADS-D) scores ≥11 – in these cohorts was low. Comparing prevalence between studies is complicated by methodological differences in assessment