The use of opioids has long been accepted as the standard of care in patients with cancer and acute pain. Opioids can further be used effectively in specific subgroups of patients with chronic nonmalignant pain states. While the development of tolerance and physical dependence are known effects of opioids in cancer and noncancer pain populations, these patients can not be regarded as addicted. However, long-term therapy with short-acting opioids predisposes to tolerance and addiction.

Recent research has confirmed the important role of psychopathologic and psychosocial conditions as predictors of failed opioid effectiveness in a significant number of noncancer pain subgroups. The clinical picture of failed therapy may be complicated by noncompliance, concealed consumption of psychotropic substances, and diversion of prescribed opioids for various purposes as, e.g., selling for profit, or sharing excess opioids with others.

This article discusses the effects of opioid therapy, including tolerance, physical dependence, drug-aberrant behavior, drug history, psychopathology, and somatization.