OBJECTIVES: Depression has been reported to be highly associated with chronic pain. It is believed that chronic pain causes depression. Our objective was to see if depression was present in patients udergoing treatment for chronic pain with opioids and if improving pain, improves depression. METHODS: A standardized depression scale was administered to chronic stable pain patients on opioids for chronic non-malignant pain. They were scored and ranked. RESULTS: Out of 98 patients, only 15% had minimal to no depression by standardized testing. There was good correlation with subsequent clinical evaluation. Eighty-five percent (85%) had mild to severe depression. Those with moderate to severe depression were referred for specialty consultation. CONCLUSIONS: Depression is common in chronic pain and the level of depression may not be predicted by level of pain, analgesic, anti-depressant useage, or mental health follow-up. Depression is easily missed and under-treated. Depression does not always respond to the concomitant treatment of pain. Patients with chronic pain should be regularly screened for depression and appropriately referred for care.