Affective symptoms, in this case depression and anxiety, have been associated with increased death rates in a National Institute for Health Research (NIHR) Maudsley Biomedical Research Centre (BRC) and Medical Research Council (MRC) funded study which examined timing and cumulative exposure over the life course.
Our researchers examined the relationship between affective problems and mortality using data from 3001 participants of the MRC National Survey of Health and Development (NSHD) cohort. The sample consisted of a group of people who were born in England, Wales and Scotland during a single week in 1946 and had been followed up 24 times over a 68 year period with questionnaires and assessments. The paper was published today (8 April 2020) in JAMA Psychiatry.
Researchers assessed affective problems across four-time points spanning from adolescence to late-adulthood (ages 13 to 53 years), and mortality was obtained from national registry data from ages 53 to 68 years.
The number of times a person experienced affective problems throughout their lifetime was linked with premature death. For those who experienced affective problems 1, 2 and 3-4 times, the premature mortality rates increased by 76%, 87% and 134% respectively, compared to those who never had affective problems. However, the timing of affective problems also appeared to be important, for example, a new episode of affective problems in later-life appeared to have the same effect on mortality as those who had affective problems 3-4 times across the life-course.
Researchers looked into whether these associations could be explained by health behaviours, such as smoking, physical activity, problem drinking and diet, health indicators, such as health conditions, lung function, resting pulse rate and blood pressure, and childhood factors, such as childhood health and adverse childhood experiences.
The association between those who had affective problems on multiple occasions and mortality was most strongly attenuated by adult health behaviours and health indicators, but these factors had less role in explaining the associations between those who experienced affective problems at a single time-point. Researchers suggest this indicates that explanatory pathways to mortality could be different depending on an individual’s history of affective problems, for example, that health behaviours have a larger explanatory role for those with chronic affective problems.
This suggests poor physical health may explain associations between affective problems and mortality, particularly in later life; perhaps through psychological or inflammatory pathways. Conversely, affective problems originating earlier in the life course are likely to be driving detrimental health behaviours e.g. smoking and low levels of physical activity, and subsequent poor health and mortality.– Lead author Dr Gemma Archer, Research Associate at Institute of Psychiatry, Psychology & Neuroscience (IoPPN), King's College London
She continues, “Notably, we found that associations were largely explained by factors in adulthood, opposed to childhood, which suggests that policies to reduce the interactions between mental and physical health might be better aimed at adults, as opposed to earlier in the life course.”
Researchers looked at explanatory pathways and found these varied with duration and timing of symptoms suggesting that further research could help identify intervention points and encourage affective symptom history to be considered.
This article was originally published on the NIHR Maudsley BRC website on 8 April 2020.