Co-occurring amphetamine use and associated medical and psychiatric comorbidity among opioid-dependent adults: Results from the Clinical Trials Network.

In response to the rising rate of treatment admissions related to illicit use of amphetamines (e.g., methamphetamine), this ancillary investigation examined the prevalence of amphetamine use among treatment-seeking, opioid-dependent adults, explored whether amphetamine users were as likely as non-amphetamine users to enroll in opioid-dependence treatment trials, and determined whether amphetamine users manifested greater levels of medical and psychiatric comorbidity than nonusers. The sample included 1257 opioid-dependent adults screened for participation in three multisite studies of the National Drug Abuse Treatment Clinical Trials Network (protocols CTN-0001, -0002, and -0003), which studied the effectiveness of buprenorphine for opioid detoxification under varying treatment conditions. Five mutually exclusive groups were examined, i.e., nonusers, current amphetamine injectors, current amphetamine non-injectors, former amphetamine injectors, and former amphetamine non-injectors Of the sample, 22.3% had a history of regular amphetamine use; of those users, 30.3% reported injection as their primary route. Amphetamine users were as likely as nonusers to enroll in treatment trials. Bivariate analyses indicated elevated rates of psychiatric problems (depression, anxiety, etc.) and medical illnesses (dermatological, hepatic, etc.) among amphetamine users. After adjusting for demographic variables and lifetime use of other substances: current amphetamine users and former injectors showed an increased likelihood of having medical illnesses and hospitalizations; current injectors had elevated odds of suicidal thoughts or attempts; current non-injectors had exhibited elevated odds of anxiety, cognitive impairment, and violent behaviors; and former non-injectors had increased odds of depression.

Conclusions: Treatment-seeking, amphetamine-using, opioid-dependent adults manifest greater levels of medical and psychiatric morbidity than treatment-seeking, opioid-dependent adults who have not used amphetamines, indicating a greater need for intensive clinical management.

Supported by the Duke Clinical Research Institute (CTN DSC 1).