Author

G. Archer

Abstract

This thesis investigated associations between lifetime affective symptoms and mortality in the MRC National Survey of Health and Development (NSHD; the British 1946 birth cohort). Affective symptoms were initially rated by teachers when study members were aged 13 and 15; then by semi-structured clinical interview at age 36 using the Present State Examination (PSE); the interview-based Psychiatric Frequency Questionnaire at age 43; and the self-report 28-item General Health Questionnaire at age 53. Mortality data including cause of death was obtained from the NHS Central Register. Follow-up time was from ages of exposure to end of October 2014 (age 68). A wide range of covariates were tested, including sex; early life factors; adult health indicators and health behaviours; psychotropic medication; stressful life events, and social factors. Cox regression showed that after adjustment for sex, severe affective symptoms were associated with an increased risk of mortality compared to those with no or mild symptoms across most ages. There was evidence of an accumulation effect where the risk of mortality increased as affective caseness increased. Adolescent-only, intermittent and chronic caseness were associated with increased risk of mortality compared to those who were never a case. There was a slightly stronger association between affective caseness and cardiovascular mortality compared to cancer mortality; however the strongest associations appeared to be with respect to deaths from 'other' causes. After full adjustment, those who were a case at a single point in time and those with adolescent-only caseness had a 46% and 73% increased risk of mortality respectively, compared to those who were never a case. All other associations were largely explained by the covariates, with most relationships attenuated predominantly by self-reported health conditions, physical activity, lung function, smoking, and psychotropic medication use. These results demonstrate the inherent interplay between affective symptoms and physical health, and highlight the importance of early intervention in order to reduce health inequalities.