The association of depression and anxiety with health-related quality of life in cancer patients with depression and/or pain

Objectives: Depression is known to he a major problem in cancer patients, and evidence is emerging about the importance of anxiety. Because the disorders are highly comorbid, we examined the relationship of anxiety and depression with health-related quality of life (HRQL) in cancer patients. Methods: Sample included 405 adult oncology patients participating in a randomized controlled trial of telecare management for pain and depression. This secondary cross-sectional analysis of baseline data examined independent and additive effects of anxiety and depression on HRQL, disability, and somatic symptom severity. Results: In 397 patients who screened positive for either pain or depression or both, 135 had comorbid anxiety and depression, 174 had depression but not anxiety, and 88 had neither. Differences existed across all nonphysical HRQL domains and were more pronounced incrementally across the three groups in the expected direction. In GLM modeling, anxiety and depression were each associated with all the domains when modeled separately (p<0.0001). When modeled together, anxiety and depression had independent and additive effects on the mental health domains of HRQL and on somatic symptom burden. In other domains (vitality, perceived disability, overall quality of life, and general health perceptions), only depression had an effect. Conclusion: Anxiety and depression have strong and independent associations with mental health domains and somatic symptom burden in cancer patients. However, depression has a more pervasive association with multiple other domains of HRQL. Paying attention to both anxiety and depression may be particularly important when addressing mental health needs and somatic symptom distress. Copyright (C) 2009 John Wiley & Sons, Ltd.