A Study on the Biobehavioral Mechanisms of Baclofen and Alcohol Drinking

Inclusion Criteria: * must be male or female between 21 and 65 years old (inclusive). * participants must meet criteria for current Diagnostic and Statistical Manual of Mental Disorders, fourth edition, text revision (DSM-IV-TR) diagnosis of alcohol dependence, supported by the Structured Clinical Interview for DSM-IV-TR Axis I Disorders Patient Edition (SCID-I/P). * participants must meet criteria for heavy drinking, defined as averaging ≥4 drinks/day for women and ≥5 drinks/day for men during a consecutive 30-day period within the 90 days prior to baseline evaluation (see: Anton et al, 2006). The gender-specific baseline was chosen as it represents heavy drinking that exceeds empirically based levels of moderate alcohol use that result in alcohol-related problems for women who consume ≥4 drinks/day, and men who consume ≥5 drinks/day (Sanchez-Craig et al, 1995). * participants must be in good health as confirmed by medical history, physical examination, ECG, lab tests. * females must be postmenopausal for at least one year, surgically sterile, or practicing an effective method of birth control before entry and throughout the study; have a negative urine pregnancy test at each visit. * participants must be willing to take oral medication and adhere to the study procedures. Exclusion criteria: * individuals expressing interest in treatment for alcoholism. * pregnancy or breast feeding women or not using an adequate form of birth control * positive urine drug screen at baseline for any illegal substance (a urine drug screen may be repeated once during the screening period). * individuals diagnosed with a current substance dependence diagnosis, other than alcohol or nicotine. * meet DSM-IV Axis I criteria for a lifetime diagnosis of schizophrenia, bipolar disorder, or other psychoses. * an active illness within the past 6 months of Visit 1 that meet the DSM-IV criteria for a diagnosis of Major Depressive Disorder (MDD) or Anxiety Disorder. Subjects with a history of suicide will be excluded. * clinically significant medical abnormalities (i.e., unstable hypertension, ECG, bilirubin \> 150% of the upper normal limit, ALT or AST elevations \>300% the upper normal limit, creatinine clearance ≤ 60 dl/min). * current use of psychotropic medications that cannot be discontinued that may have an effect on alcohol consumption or that may interact with baclofen or cyproheptadine. * medical contraindications for use of baclofen or cyproheptadine. * a history of adverse reaction or hypersensitivity to baclofen or cyproheptadine. * individuals with a reasonable expectation of being institutionalized during the course of the trial. * participants who have significant alcohol withdrawal symptoms, defined as a Clinical Institute Withdrawal Assessment for Alcohol (CIWA-Ar) \>10. * history of seizures (e.g. epilepsy). * subjects who have participated in any behavioral and/or pharmacological study within the past 90 days.