Mental health-related quality of life mediates the association between psychosocial factors and medication adherence in rheumatoid arthritis.

OBJECTIVE: Medication adherence remains a major challenge in the long-term management of rheumatoid arthritis (RA). While clinical determinants of adherence have been widely studied, the psychological mechanisms through which individual differences influence adherence behavior are less well understood. The present study aimed to examine a theoretically informed model linking personality traits, coping-related humor styles, mental health-related quality of life, and medication adherence in patients with RA.

METHODS: A cross-sectional study was conducted in a sample of adults diagnosed with RA. Participants completed established self-report measures assessing personality traits (Extraversion, Neuroticism), humor styles (self-enhancing, self-defeating), mental health-related quality of life (SF-36 Mental Component Summary), and medication adherence (Morisky Medication Adherence Scale). Ordinal logistic regression was initially performed to examine direct predictors of adherence. Subsequently, path analysis was used to test a mediation model in which mental health-related quality of life was specified as a proximal determinant of adherence.

RESULTS: Mental health-related quality of life emerged as the only significant direct predictor of medication adherence. Personality traits and humor styles were not directly associated with adherence. Higher Neuroticism and greater use of self-defeating humor were associated with poorer mental health-related quality of life, whereas Extraversion was positively associated with mental health-related quality of life. Path analysis demonstrated that the associations between personality traits, humor styles, and adherence were statistically accounted for by indirect pathways through mental HRQoL.

CONCLUSION: The findings indicate that mental health-related quality of life represents a central psychological pathway linking dispositional characteristics to medication adherence in rheumatoid arthritis. Rather than exerting direct effects, personality traits and coping-related humor styles influence adherence indirectly through their impact on patients' mental health. These results underscore the importance of integrating psychological assessment and support into routine rheumatology care to promote sustained adherence and optimize long-term outcomes. These findings have direct implications for routine rheumatology care, highlighting the importance of addressing mental health alongside pharmacological management. Key Points • Mental health-related quality of life (HRQoL) was the only significant direct predictor of medication adherence in patients with rheumatoid arthritis. • Personality traits and humor styles were not directly associated with adherence; their associations operated indirectly through mental HRQoL. • Higher Neuroticism and self-defeating humor were associated with poorer mental HRQoL, whereas Extraversion was associated with better mental HRQoL. • Brief psychological assessment within routine rheumatology care may help identify patients at risk for suboptimal adherence.