# Depression does not moderate the association between beliefs about medicines and medication adherence in patients with rheumatoid arthritis: A longitudinal study

## TL;DR

This study found that depression does not affect how beliefs about medications influence medication adherence in rheumatoid arthritis patients over time.

## Contribution

The study challenges previous findings by showing no moderating role of depression in medication adherence beliefs in a longitudinal RA cohort.

## Key findings

- Two-thirds of rheumatoid arthritis patients were non-adherent to their medications.
- No significant interaction was found between depression and medication beliefs in influencing adherence.
- Longitudinal analysis suggests depression may not robustly moderate medication adherence as previously thought.

## Abstract

Non-adherence is common in people with rheumatoid arthritis (RA). According to the ‘necessity-concerns framework’, beliefs about the necessity and concerns about prescribed medications influence adherence. The present study’s objective was to investigate whether depression moderates associations between beliefs about medicines and adherence among people with physician-diagnosed RA in a longitudinal study (N = 361; 31% male, mean age [SD] 60.2 [13.4]). Adherence (adherent vs non-adherent; MARS), beliefs about medicines (BMQ), and depression (HADS) were assessed at baseline, 3- and 12-month follow-up. Multivariate logistic regression models were calculated (predictors: necessity/concerns, depression; outcome: adherence). Two-thirds of patients were non-adherent. No significant interactions were found between necessity/concerns and depression. Contrary to previous cross-sectional research, we did not find evidence for a moderating role of depression in associations between beliefs about medicines and adherence. Possible moderating effects of depression might be less robust than previously thought and therefore harder to detect in longitudinal analyses.