(278) Diabetes Mellitus, Antidiabetic Use and The Risk of Treated Depression in the UK

Friday, August 26, 2022

8:00 AM – 6:00 PM CEST

Location: Hall C

Publication Number: 609

Presenting Author(s)

Claudia Becker, PhD
– University of Basel, Basel, Switzerland

Co-Author(s)

Delia Bornand
– Basel Pharmacoepidemiology Unit, Div of Clin Pharmacy & Epidemiology, Dep of Pharm Sciences, University of Basel, Switzerland
Susan Jick, DSc
– Director, Boston Collaborative Drug Surveillance Program, Lexington, MA, United States
Christoph Meier, Prof Dr
– Basel Pharmacoepidemiology Unit, Division of Clinical Pharmacy and Epidemiology, Department of Pharmaceutical Sciences, University of Basel, Basel, Switzerland, Switzerland

Background: Diabetes mellitus (DM) and depression are highly prevalent chronic diseases, both affecting quality of life and reducing life expectancy. Two previous studies from Denmark on this topic yielded conflicting results.

Objectives: To assess the association of DM and antidiabetic treatment with the risk of incident treated depression in primary care in the UK.

Methods: In the UK-based Clinical Practice Research Datalink (CPRD) database, we identified patients with incident, treated depression (date of first recording named ‘index date’, [ID]) and matched them (1:1 on age, sex, calendar time and GP practice) to controls free of recorded depression. In a second analysis, we only included cases of depression among a subgroup of patients with diabetes mellitus type 2 (T2DM) and matched them (1:4 on age, sex, calendar time and DM duration) to diabetic controls. Patients were 18 to 90 years at the index date with >3 years of history in the database and without a history of alcoholism, cancer or HIV. We conducted conditional logistic regression and adjusted the final model for BMI, smoking and alcohol status, several comorbidities, use of antipsychotic or hypnotic drugs at any time before the ID, and number of GP visits in the year before the ID.

Results: We identified 254’559 patients with incident treated depression between 1995 and 2020. Patients with T1DM (adj. OR 1.34, 95% CI 1.22-1.48) as well as patients with T2DM (adj. OR 1.72, 95% CI 1.63-1.81) were more prevalent among cases with depression. We observed the highest relative risk for treated depression in men with T2DM aged 18 to 49 years (adj. OR 2.17, 95% CI 1.82-2.59) whereas women with T2DM of the same age had a lower risk (adj. OR 1.47, 95% CI 1.26-1.72).
The analysis nested in patients with T2DM encompassed 3’827 cases with depression and 14’481 controls. Patients had a mean duration of DM of 3.7 years (SD ±3.2 years) at the date of the depression diagnosis. Patients who were treated with metformin alone had an increasing risk of depression according to the number of Rx for metformin (1-4 Rx: adj. OR 1.15, 95% CI 0.97-1.37; 5-19 Rx: adj. OR 1.42, 95% CI 1.23-1.64; ≥20 Rx: adj. OR 2.14, 95% CI 1.82-2.52) compared to non-users. Users of metformin plus one or more other antidiabetic drug (sequential use was possible) had a two to threefold increased risk of treated depression compared to non-users.

Conclusions: Compared to the general population, patients with DM were at an increased risk of treated depression. Users of metformin (monotherapy or combined therapy) had an increased risk of depression compared to non-users of antidiabetic drugs.