Below is the abstract of the manuscript that summarizes the findings:
Objectives: Recent regulatory warnings suggest that high-dose hydroxychloroquine for novel coronavirus disease 2019 (COVID-19) could cause depression or suicidal ideation. We aimed to study whether there is risk of depression, suicidal ideation, or psychosis associated with hydroxychloroquine use for rheumatoid arthritis (RA).
Methods: A new user cohort study using claims and electronic medical records from 10 sources and 3 countries (Germany, UK, and US) was used. Rheumatoid arthritis patients aged 18+ and initiating hydroxychloroquine were compared to those initiating sulfasalazine (active comparator) and followed up in the short (30-day) and long term (on treatment). Study outcomes were depression, suicide/suicidal ideation, and hospitalization for psychosis. Propensity score stratification and calibration using negative control outcomes were used to address confounding. Cox models were fitted to estimate database-specific calibrated hazard ratios (HR), with estimates pooled where I2<40%.
Results: Overall, 918,144 and 290,383 users of hydroxychloroquine and sulfasalazine, respectively, were included. No consistent risk of psychiatric events was observed with short-term hydroxychloroquine (compared to sulfasalazine) use, with meta-analytic HRs of 0.96 [95% CI 0.79-1.16] for depression, 0.94 [0.49-1.77] for suicide/suicidal ideation, and 1.03 [0.66-1.60] for psychosis. Long-term effects were similar, with meta-analytic HRs 0.94 [0.71-1.26] for depression, 0.77 [0.56-1.07] for suicide/suicidal ideation, and 0.99 [0.72-1.35] for psychosis.
Conclusions: Hydroxychloroquine as used to treat RA does not appear to increase the risk of depression, suicide/suicidal ideation, or psychosis compared to sulfasalazine. No effects were seen in the short (first month of treatment) or in the long term. Use at higher dose or for different indications might have other effects and needs further investigation.
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