The study will consist of 1 to 2 outpatient screening visits, followed by up to 15 days of inpatient detoxification treatment and assessment. After hospital discharge from inpatient treatment, measures of protracted GHB withdrawal and psychiatric symptoms will be obtained on an outpatient weekly basis for 8 weeks. Repeat measures of cognitive functioning will be obtained at baseline, termination of treatment, and at 30, 60, and 90-day follow-up intervals in order to assess long-term neurocognitive effects of GHB withdrawal and use.