Effect of Psychological Inflexibility on Depressive Symptoms and Sleep Disturbance among Japanese Young Women with Chronic Pain

Background: Psychological inflexibility based on an acceptance and commitment therapy model is theoretically well-established as a process to exacerbate psychological distress, such as depressive symptoms and sleep disturbance. This study aimed to examine the associations of psychological inflexibility with depressive symptoms and sleep distribution. We hypothesized that psychological inflexibility would be associated with higher levels of depressive symptoms and sleep disturbance in women with chronic pain. Methods: Female college students in Japan answered a questionnaire on pain status, treatment, and psychological inflexibility as measured by the Acceptance and Action Questionnaire-Ⅱ before answering questionnaires on depressive symptoms and sleep disturbance eight months after. Results: Women with chronic pain (n = 320) reported more severe depressive symptoms and sleep disturbances compared to women without chronic pain (n = 90). Hierarchical multiple regressions revealed that psychological inflexibility predicted higher levels of depressive symptoms and sleep disturbance, independent of the pain intensity, whether they consulted a doctor or used pain medication. Conclusion: Based on our findings self-management interventions aimed at reducing psychological inflexibility should be developed for individuals who are experiencing chronic pain.