NCMD Research Seminar Series 19th September 2025

Presenter: Dr Annie Jeffery, Epidemiologist and Senior Research Fellow in the Department of Epidemiology and Applied Clinical Research, Division of Psychiatry, UCL

"Association between polypharmacy and depression relapse in individuals with comorbid depression and type 2 diabetes: a UK electronic health record study"

Individuals with physical comorbidities and polypharmacy may be at higher risk of depression relapse, however, they are not included in the 'high risk of relapse' group for whom longer antidepressant treatment durations are recommended. In individuals with comorbid depression and type 2 diabetes (T2DM), we aimed to investigate the association and interaction between depression relapse after stopping antidepressant treatment and (a) polypharmacy, (b) previous duration of antidepressant treatment. We performed a cohort study using primary care data from the UK Clinical Practice Research Datalink (CPRD) from years 2000 to 2018. We used Cox regression models with penalised B-splines to describe the association between restarting antidepressants and our two exposures. As polypharmacy increased, the rate of restarting antidepressants increased. As the duration of previous antidepressant treatment increased, the rate of restarting antidepressants increased. We found no interaction between polypharmacy and previous antidepressant duration.
Annie is an experienced epidemiologist and Senior Research Fellow in the Department of Epidemiology and Applied Clinical Research, Division of Psychiatry, UCL. Her research interests include the effect of common mental disorders on physical health, the effects of wider-determinants of health, Bayesian epidemiology, pharmacoepidemiology and advancing methods of causal inference in observational data.