Gabapentin Treatment of Cannabis Dependence

This is a 12-week, double blind, placebo controlled study to evaluate the efficacy of
gabapentin in treating outpatients with cannabis dependence. After an initial phone screen,
a comprehensive screening visit is scheduled to determine eligibility. Baseline assessments
using measurement instruments are conducted on cannabis use, neuropsychological functioning,
withdrawal, craving, pain, mood and sleep. Upon enrollment, counseling, medication
dispensation and research assessments occur 1 time per week for 3 months and include
assessments in withdrawal, craving, pain, mood and sleep. A final, follow-up visit occurs at
the end of the 3 months.

Inclusion Criteria:

- Males or females from 18-65 years of age

- Meets DSM IV criteria for current cannabis dependence

- Seeking research-based outpatient treatment for cannabis dependence that involves
daily medication

- Smoked MJ daily at least 25 days per month during the 90 days prior to randomization

- At least a 2-year history of regular MJ use

Exclusion Criteria:

- Abstinent from cannabis more than 2 days at the time of randomization

- Active suicidal ideation

- Currently meets DSM IV criteria for abuse or dependence on other substances, or has
urine drug screen positive for substances, other than cannabis or nicotine

- Significant medical disorders that will increase potential risk or interfere with
study participation,

- Sexually active female participants with childbearing potential who are pregnant,
nursing or refuse to use a reliable method of birth control

- Meets DSM IV criteria for a major AXIS I disorder other than cannabis and nicotine
dependence,

- Inability to understand and/or comply with the provisions of the protocol and consent
form

- Treatment with an investigational drug during the previous month

- Sensitivity to study drug as evidenced by adverse drug experiences with gabapentin or
its ingredients

- Ongoing treatment with medications that may affect study outcomes