Antidepressant use and risk of adverse outcomes: population-based cohort study

Antidepressants are one of the most widely prescribed drugs in the global north. However, little is known about the health consequences of long-term treatment.

This study aimed to investigate the association between antidepressant use and adverse events.

The study cohort consisted of UK Biobank participants whose data was linked to primary care records (N = 222 121). We assessed the association between antidepressant use by drug class (selective serotonin reuptake inhibitors (SSRIs) and 'other') and four morbidity (diabetes, hypertension, coronary heart disease (CHD), cerebrovascular disease (CV)) and two mortality (cardiovascular disease (CVD) and all-cause) outcomes, using Cox's proportional hazards model at 5- and 10-year follow-up.

SSRI treatment was associated with decreased risk of diabetes at 5 years (hazard ratio 0.64, 95% CI 0.49-0.83) and 10 years (hazard ratio 0.68, 95% CI 0.53-0.87), and hypertension at 10 years (hazard ratio 0.77, 95% CI 0.66-0.89). At 10-year follow-up, SSRI treatment was associated with increased risks of CV (hazard ratio 1.34, 95% CI 1.02-1.77), CVD mortality (hazard ratio 1.87, 95% CI 1.38-2.53) and all-cause mortality (hazard ratio 1.73, 95% CI 1.48-2.03), and 'other' class treatment was associated with increased risk of CHD (hazard ratio 1.99, 95% CI 1.31-3.01), CVD (hazard ratio 1.86, 95% CI 1.10-3.15) and all-cause mortality (hazard ratio 2.20, 95% CI 1.71-2.84).

Our findings indicate an association between long-term antidepressant usage and elevated risks of CHD, CVD mortality and all-cause mortality. Further research is needed to assess whether the observed associations are causal, and elucidate the underlying mechanisms.