Heavy marijuana users report experiencing trouble sleeping when they try to quit, but this has not been carefully studied. This research is being done to learn more about sleep function in heavy marijuana users, and to determine whether a medication approved for treating insomnia can help restore normal sleep function during brief periods of abstinence.

Inclusion Criteria:

• current use of marijuana
• able to give informed consent

Exclusion Criteria:

• dependence on drug other than marijuana
• current sleep disorder
• pregnant, breast feeding, or planning to become pregnant within the next 3 months
• currently seeking treatment for cannabis-related problems or otherwise trying to reduce use
• use of cannabis under the guidance of a physician for a medical disorder
• unstable or uncontrolled cardiovascular disease (e.g., hypertension, angina)
• allergy to study medication