D1 and D2 Dopamine Receptors in Gambling and Amphetamine Reinforcement
Condition: Pathological Gambling
MeSH terms: Gambling
Intervention: Haloperidol; Fluphenazine; Dexedrine; Placebo; Slot Machine
Intervention description: Dose/maximum dose = 3-mg; route = oral. Participants assigned to the haloperidol antagonist group will receive 2 doses (@ 3 mg) on alternate sessions (with minimum of 2 weeks between individual doses).
Dose 1: 3 visually identical capsules, each containing 1 mg haloperidol.; Dose/maximum dose = 3-mg; route = oral. Participants assigned to the fluphenazine antagonist group will receive 2 doses (@ 3 mg) on alternate sessions (with minimum of 2 weeks between individual doses).
Dose 1: 3 visually identical capsules, each containing 1 mg fluphenazine.; Dose/maximum dose = 20-mg; route = oral. All participants will receive 2 doses (@ 20 mg) during Phase II - sessions 3, 4, with minimum 1 week between individual doses.
Dose 2: when participants reach expected peak blood levels for dose 1, they will receive their second dose. On sessions 3 and 4 (Phase II), the dose will consist of 2 visually identical capsules each containing 10 mg D-amphetamine.; Dose 1: On alternate sessions (1 and 3 or 2 and 4, depending on counterbalancing) participants will receive 3 visually identical placebo (lactose) capsules.
Dose 2: when participants reach expected peak blood levels for dose 1, they will receive their second dose. On sessions 1 and 2 (Phase I), this will consist of 2 dummy capsules, visually identical to those administered for dose 1.; 15 minute play of a commercial slot machine game in bar-simulated laboratory setting.
Intervention MeSH terms: Haloperidol; Haloperidol decanoate; Fluphenazine; Fluphenazine depot; Fluphenazine enanthate; Amphetamine; Dextroamphetamine
Phase: Phase 2
Study type: Interventional
Primary purpose: Diagnostic
Allocation: Randomized
Intervention model: Parallel Assignment
Masking: Triple (Participant, Investigator, Outcomes Assessor)
Enrollment: 60.0
Sex: All
Minimum age: 19 Years
Maximum age: 65 Years
Healthy volunteers: Accepts Healthy Volunteers
Keywords: amphetamine; d1 and d2 receptors; dopamine antagonists; pathological gambling; priming; reinforcement

Summary:

      To determine if:

        1. pathological gambling is similar to psychostimulant addiction as reflected by parallel
           roles for D1 and D2 receptors in gambling and stimulant reinforcement.

        2. these parallel roles are linked with gambling pathology or if they are evident in both
           gamblers and controls.
    

Eligibility criteria:

        Inclusion Criteria:

          -  PATHOLOGICAL GAMBLERS

          -  otherwise healthy, non-treatment seeking, non-abstinent

          -  male or female

          -  ages 19-65

          -  DSM-IV PG symptom scale score > 5

          -  SOGS (South Oaks Gambling Screen) score > 5

          -  nicotine dependence acceptable

          -  CONTROLS

          -  healthy

          -  male or female

          -  ages 19-65

          -  DSM-IV PG symptom scale score = 0

          -  SOGS score = 0

          -  nicotine dependence acceptable

          -  must have played slot machine > 5 times

        Exclusion Criteria:

          -  both Pathological Gamblers and Controls

          -  Axis I psychopathology aside from nicotine dependence (or PG) based on SCID

          -  Schizotypal or Borderline Personality Disorder based on psychiatric interview

          -  Family history of schizophrenia or bipolar disorder

          -  English comprehension below grade 7 level.

          -  ADS (Alcohol Dependence Scale) > 13 (more than low dependence)

          -  BDI (Beck Depression Inventory) short form > 10 (more than low depression)

          -  DAST (Drug Abuse Screening Test) > 4 (possible drug abuse)

          -  Consumption of > 20/15 (men/women) standard alcoholic drinks/ week (hazardous
             drinking)

          -  Smoking > 20 cigarettes/day to help minimize withdrawal symptoms during test phase

          -  Any prior use of psychostimulant drugs

          -  Current use of medication that could interact with any of the study medications

          -  Women who are pregnant or breastfeeding