Psychological factors as predictors of opioid abuse and illicit drug use in chronic pain patients.

BACKGROUND Psychopathology (depression, anxiety, somatization disorder) and substance abuse (opioid misuse and illicit drug use) are common in patients with chronic pain and present problems for public health and clinical management. Despite a body of literature describing various methods for identifying psychopathology, opioid misuse, and illicit drug use in chronic pain patients, the relationship between psychopathologies, substance abuse, and chronic pain has not been well characterized.

METHODS This report describes a total of 500 consecutive pain patients prescribed and receiving stable doses of opioids. The patients were evaluated for psychopathology, opioid abuse, and illicit drug use during the course of regular pain management treatment. The relationships between psychopathology and drug abuse and/or illicit drug use in chronic pain patients were examined, and psychological evaluation for depression, anxiety, and somatization disorder was performed.

RESULTS Depression, anxiety, and somatization disorder were documented in 59, 64, and 30 percent of chronic pain patients, respectively. Drug abuse was significantly higher in patients with depression as compared to patients without depression (12 percent with depression versus 5 percent without). Current illicit drug use was higher in women with depression (22 percent) than women without depression (14 percent) and in men with or without depression (12 percent). Current illicit drug use was also higher in men with somatization disorder (22 percent) than men without (9 percent).

CONCLUSION This study demonstrated that the presence of psychological features of depression and somatization disorder may be markers of substance abuse diathesis in chronic pain patients.