Desvenlafaxine in Opioid-Dependent Patients

All subjects will receive 50 mg of the medication during week 1 and 2, then 50-100 mg (based on the psychiatrist judgment) for the following 6 weeks. Subjects who experience significant adverse reactions with the 100mg dose during weeks 2 to 4 could return to the lower dose of 50 mg if judged clinically appropriate by the study psychiatrist.