Cross-sectional analysis of pharmaceutical industry payments to authors of clinical practice guidelines for bipolar disorder and major depressive disorder in Japan

Abstract

Objective Clinical practice guidelines (CPGs) are essential for standardising patient care based on evidence-based medicine. However, the presence of financial conflicts of interest (COIs) among CPG authors can undermine their credibility. This study aimed to examine the extent and size of COIs among authors of psychiatry CPGs in Japan.Methods This cross-sectional analysis of disclosed payments from pharmaceutical companies assesses the prevalence and magnitude of personal payments for lecturing, consulting and writing to CPGs for bipolar disorder and major depressive disorder in Japan between 2016 and 2020.Results This study found that 93.3% of authors received payments over a 5-year period, with total payments exceeding US$4 million. The median payment per author was US$51 403 (IQR: US$9982–US$111 567), with a notable concentration of payments among a small number of authors, including the CPG chairperson. Despite these extensive financial relationships, only a fraction of authors disclosed their COIs in the CPGs. These large amounts of personal payments were made by pharmaceutical companies manufacturing new antidepressants and sleeping aids listed in the CPGs.Conclusions This study found that more than 93% of authors of CPGs for major depressive disorder and bipolar disorder in Japan received considerable amounts of personal payments from the pharmaceutical industry. The findings highlight deviations from international COI management standards and suggest a need for more stringent COI policies for psychiatry CPGs in Japan.