The study aims to study the effect of gabapentin on the number of alcohol drinking days and heavy drinking days in the Thai clinical alcohol-dependent population by using the double-blinded randomized controlled approach. One-hundred and twelve individuals with alcohol dependence were randomly assigned equally into two groups including treatment with gabapentin and placebo. Thirty-four patients (30.3%) completed the study protocol, i.e. treatment with gabapentin at least 300 mg per day or placebo orally once a day for twelve weeks. Pattern of alcohol drinking were obtained from the timelime followback. Drinking behaviors were compared between the two groups by poisson repeated measures model.

Inclusion Criteria:

• current diagnosis of alcohol dependence

Exclusion Criteria:

• having major psychiatric disorders including schizophrenia, schizoaffective disorder, bipolar disorder, major depressive disorder, or suicide risk based on a clinical interview by attending psychiatrist
• receiving other medications not in the protocol of the study for any reasons or having history of using other substances including methamphetamine, heroin, cannabis, inhalants, mitragyna speciosa (or kratom in Thai), except tobacco based on self-report
• having a medical disease, e.g. essential hypertension, diabetes, renal (e.g., normal renal test) or liver disease (e.g., liver function test was not higher than two times of normal range and gamma-glutamyl transferase (GGT) is less than 800 U/L), epilepsy, stroke
• having history of alcohol withdrawal seizure or delirium based on clinical interview by attending psychiatrist
• having moderate to severe alcohol withdrawal symptoms based on score >13 of the Clinical Interview for Withdrawal Alcohol Arlington (CIWA - Ar) at the time of recruitment
• having cognitive impairment based on score < 24 from the Mini Mental State Exam (MMSE)
• having history of allergy to gabapentin
• pregnancy or breast feeding.