Psychological Flexibility and Depression in Advanced CKD and DialysisPlain-Language Summary

Rationale & Objective: Depression is prevalent and highly associated with mortality among patients with chronic kidney disease (CKD). Psychological flexibility can be captured as acceptance in psychology, and its improvement by behavioral therapy is associated with reduced depression in some clinical settings. However, no study has been reported on patients with CKD. This study aimed to examine the association between psychological flexibility and depression in patients with CKD. Study Design: Cohort study. Setting & Participants: This multicenter study of 5 hospitals in Japan included patients with nondialysis stage 3-5 CKD or stage 5D CKD receiving hemodialysis or peritoneal dialysis. Predictor: Psychological flexibility measured using the 7-item Acceptance and Action Questionnaire (AAQ-II). Outcomes: The prevalence and incidence of depression after 1 year, which was defined by a score ≥ 16 points on the Center for Epidemiologic Studies Depression (CES-D) questionnaire. Analytical Approach: Gamma regression was used in the examination of correlates of the psychological flexibility value. Modified Poisson regression models were fit for the prevalence and incidence of depression. Results: The cross-sectional and longitudinal analyses included 433 and 191 patients, respectively. Lower (ie, worse) psychological flexibility levels were associated with hemodialysis and peritoneal dialysis. Higher (ie, better) psychological flexibility levels were associated with lower prevalence of depression (per 5-point increase; adjusted prevalence ratio, 0.75; 95% CI, 0.70-0.80) and lower incidence of depression (per 5-point increase; adjusted risk ratio, 0.72; 95% CI, 0.61-0.85). Limitations: Depression was assessed using the CES-D questionnaire. Cultural differences may exist in the interpretation of AAQ-II scores. Conclusions: Better psychological flexibility was associated with lower prevalence and incidence of depression in patients with CKD. Further studies are warranted to determine the possible prevention and treatment of depression by the development of behavioral interventions to improve psychological flexibility.