Vivitrol for Reducing Driving While Impaired Behavior Among Repeat Offenders

Inclusion Criteria * Age ≥ 18 * Capable of understanding and complying with the protocol, and has signed the informed consent document * Been convicted of a DWI offense, have at least one additional arrest for DWI, and be entering an ignition interlock program * They must be able to participate in a 6 month outpatient study; and reside within a one-hour commute to the research site * Women of childbearing potential must have a negative pregnancy test, use contraceptive methods, and not be breastfeeding * Negative urine toxicological screen for opiates at screening and randomization * Has a non-custodial stable residence and telephone Exclusion Criteria * Is pregnant and/or currently breastfeeding * Has a clinically significant medical condition or observed abnormality that is contraindicated for Vivitrol treatment * Is taking an excluded medication, including but not limited to benzodiazepines, anticonvulsants, opiates, or alcohol treatment medication * Not stable on current anti-depressant, as evidenced by less than 3 months at current dosage, plans to discontinue, or plans to change the dosage * Has been hospitalized for medical detoxification within 30 days of screening * Has evidence of severe kidney, heart, or lung disease * Has evidence of severe hepatic disease (as evidence by BUN \> 10% above ULN, AST, ALT \> 3x ULN, and GGT \> 5x ULN at randomization) * Known or suspected hypersensitivity to naltrexone and/or Vivitrol in particular * Current diagnosis and symptoms of major depression, anxiety disorder, mania or psychosis (subjects with their illness in remission for 3 months may be included) * Opioid use within the past 14 days and/or current or recent (within the past year) diagnosis of dependence or abuse of opiates, benzodiazepines, or cocaine. * Current or anticipated need for prescribed opiate medication during the study period * Medication with naltrexone, disulfiram, acamprosate or other medication used to treat alcoholism within the past 30 days * Impending incarceration or other known situation that would preclude participation in the study * Other non-alcohol Axis I substance dependence diagnosis in the past 12 months, excluding nicotine, marijuana, and caffeine * Has participated in a clinical trial of a pharmacological agent within 30 days of screening * Has any finding that in the view of the principal investigator would compromise the subject's ability to fulfill the protocol visit schedule, and/or visit requirements or would affect subject safety during participation