Effects of Buprenorphine/Naloxone Dose on Experimental Stress Reactivity and Opioid Abstinence

Inclusion Criteria: * Opioid dependent, as determined by structured clinical interview for DSM-IV (SCID) and Addiction Severity Index (ASI) * Positive urine test for opiates * Willing to use an adequate form of contraception for the duration of the study. * Reads and writes English * Participants must be in generally good health to be eligible. All candidates will receive a routine medical exam (history and physical) with standard laboratory tests (including blood and urine samples, EKG, mandatory TB testing, and voluntary HIV testing). Exclusion Criteria: * No candidate who has a current DSM-IV Axis I disorder other than Drug Dependence or a history of serious psychiatric problems (e.g. psychosis, bipolar or major depression) will be allowed to participate. * Candidates meeting criteria for opioid or nicotine dependence will not be excluded, but those with other Substance Dependence disorders will be excluded. Those with Abuse of Alcohol, Cannabis, Cocaine, will not be excluded, but participants must provide an alcohol free breath specimen. * No candidate with medical (neurological, cardiovascular, pulmonary or systemic) disorders will be allowed to participate. This will be determined with history and physical exam, standard laboratory testing (blood and urine), EKG, and TB tests (to avoid transmitting this communicable disease on the residential unit or in the laboratory). * Candidates with evidence of cognitive impairment (based on reading ability and comprehension, wi…