Effects of pain-related catastrophic thinking, anxiety, and depression on pain intensity and quality of life in patients with knee and low back pain.

[Purpose] We aimed to examine the effects of pain-related catastrophic thoughts and anxiety/depression on pain intensity and quality of life (QOL), and how these effects (relationships) vary with pain location, in outpatients with chronic pain. [Participants and Methods] We recruited 14 participants with low back pain (2 males and 12 females) and 14 with knee joint pain (3 males and 11 females). We used the following evaluation tools: the visual analog scale (to evaluate pain intensity), pain catastrophizing scale (in which scores are categorized into helplessness, rumination, and magnification), Hospital Anxiety and Depression Scale (for psychodynamic evaluation), and a questionnaire for QOL evaluation. [Results] There was no difference in pain intensity between the groups. The "low back pain" group showed a positive correlation between pain intensity and anxiety, while the "knee pain" group showed a positive correlation between pain intensity and helplessness. The "low back pain" group showed a negative correlation between health in QOL assessment items and helplessness, and between health and magnification. However, in the "knee pain" group, there was a negative correlation between health and rumination, between health and anxiety, and between positive mental attitude and magnification. [Conclusion] Mental status varied depending on the pain location, regardless of the intensity of the pain. This suggests that a psychological approach dependent on pain location is needed during physical therapy.