This 7 week, open-label pilot clinical trial will examine the safety and tolerability of modafinil up to 400mg/day as a potential treatment to reduce methamphetamine use in methamphetamine-dependent volunteers.

Inclusion Criteria:

• 18-65 years old
• not currently enrolled in a treatment program
• subjects must have a history of methamphetamine use with recent use confirmed by a positive urine toxicology screen for amphetamines during themonth prior to study entry
• subjects must meet DSM-IV criteria for amphetamine dependence as assessed by the substance abuse section of the Structured Clinical Interview for DSM-IV (SCID)
• women of childbearing age must have a negative pregnancy test to enroll in this study, agree to monthly pregnancy testing, and agree to use appropriate forms of birth control for the duration of the study

Exclusion Criteria:

• current diagnosis of alcohol, opiate, or sedative physical dependence
• ill health (e.g., major cardiovascular, renal, endocrine, hepatic disorder)
• history of schizophrenia, or bipolar type I disorder
• present or recent use of over-the-counter or prescription psychoative drug or drug(s) that would be expected to have major interaction with drug to be tested
• medical contraindication to receiving study medications (e.g., allergy to modafinil, treatment with cyclosporine, clomipramine, or desipramine)
• Current suicidality or psychosis
• liver function tests (i.e., liver enzymes) greater than three times normal levels
• pregnancy or breastfeeding