Background Depression is associated with a range of adverse health outcomes, including reduced life expectancy and increased incidence of physical health conditions. The aim of this study was to quantify the association between depression and the subsequent accrual of 69 long term physical health conditions in middle age.

Methods We used data from the UK Biobank cohort. Participants, aged between 40 and 69 years, attended a baseline assessment between 2006 and 2010 and were followed up through linked health data. We included participants with primary care data. We identified depression at baseline from primary care and hospital records. We ascertained the presence of 69 physical health conditions at baseline and during follow-up from the baseline assessment and primary care, hospital, cancer registry and death records. We used quasi-Poisson models to compare the rate of physical health condition accrual during follow-up between participants with and without baseline depression. Models were sequentially adjusted for sociodemographic characteristics and baseline health and lifestyle factors. We included participants with complete data on all variables.

Results Our cohort included 113,292 participants. Of these, 19,010 (16.8%) had a history of depression at baseline. During an average of 7 years follow-up, participants with depression accrued an average of 0.20 additional physical health conditions per year compared to 0.16 conditions per year for participants without depression. The most common additional conditions in both groups were osteoarthritis (11.5% of participants with depression, 10.1% of participants without depression) and hypertension (8.6% with depression, 8.5% without depression). Based on the fully adjusted quasi-Poisson model, the rate of accrual of additional physical health conditions was 1.11 (95% confidence interval: 1.09, 1.13) times higher in those with depression, compared to people without depression.

Conclusion Middle age adults with depression accrued morbidities at a faster rate than those without depression. Routine care for middle age adults with depression should go beyond depression treatment and include a holistic approach to the prevention and early diagnosis of physical health conditions. The strengths of this study were that we used a large cohort with a long follow-up and that we included a broad range of physical health conditions identified from multiple data sources. A key limitation was that only participants with complete data were included, however a multiple imputation including all eligible participants is currently under way.