Effect of D-amphetamine on Reward Functioning

Purpose

The purpose of this study is to establish the dose-response curve for therapeutic doses of d-amphetamine on tasks of motivation and reward learning in the same participants and to use d-amphetamine as a dopaminergic probe to test newer theories about the role of dopamine in reward-related decision-making.

Condition

  • Anhedonia

Eligibility

Eligible Ages
Between 18 Years and 35 Years
Eligible Genders
All
Accepts Healthy Volunteers
Yes

Inclusion Criteria

  • Healthy individuals

Exclusion Criteria

  • Individuals with a body mass index (BMI) <19 or >26, as this alters dosing requirements - Individuals with high blood pressure, abnormal Electrocardiography (EKG), any medical condition requiring regular medication (except birth control), any other regular use of a drug or supplement with potentially hazardous interactions with d-amphetamine (e.g. St. John's wort), or any other medical contraindication to amphetamine administration as determined by our study physician - Individuals who report no prior experience with recreational drugs of any kind (including alcohol), or who report a previous adverse reaction to amphetamine - Individuals with a current Diagnostic and Statistical Manual of Mental Disorders-V (DSM-V) Axis I diagnosis, excluding mild Substance Use Disorders (≤ 3 symptoms) - Individuals with a lifetime history of moderate to severe Substance Use Disorder (≥ 4 symptoms), mania or psychosis. - Women who are pregnant. - individuals smoking more than 10 cigarettes per week will also be excluded, to avoid confounding the effects of nicotine withdrawal with the effects of the study drugs/procedures, as participants will not be allowed to smoke during the sessions. - individuals with less than a high-school level of education or fluency in English will be excluded as our questionnaires require high-school level fluency in English, and have not been translated and validated in other languages.

Study Design

Phase
Phase 1
Study Type
Interventional
Allocation
Randomized
Intervention Model
Parallel Assignment
Primary Purpose
Basic Science
Masking
Single (Participant)

Arm Groups

ArmDescriptionAssigned Intervention
Experimental
Placebo, then 10 mg d-amphetamine, then 20mg d-amphetamine
  • Drug: 10 mg d-amphetamine
    10 mg d-amphetamine dose given (double-blind) and behavioral tasks (EEfRT, PRT, ELT, CGT) administered.
  • Drug: 20mg d-amphetamine
    20 mg d-amphetamine dose given (double-blind) and behavioral tasks (EEfRT, PRT, ELT, CGT) administered.
  • Drug: Placebo
    Placebo dose given (double-blind) and behavioral tasks (EEfRT, PRT, ELT, CGT) administered.
Experimental
Placebo, then 20 mg d-amphetamine, then 10mg d-amphetamine
  • Drug: 10 mg d-amphetamine
    10 mg d-amphetamine dose given (double-blind) and behavioral tasks (EEfRT, PRT, ELT, CGT) administered.
  • Drug: 20mg d-amphetamine
    20 mg d-amphetamine dose given (double-blind) and behavioral tasks (EEfRT, PRT, ELT, CGT) administered.
  • Drug: Placebo
    Placebo dose given (double-blind) and behavioral tasks (EEfRT, PRT, ELT, CGT) administered.
Experimental
10 mg d-amphetamine, then placebo, then 20mg d-amphetamine
  • Drug: 10 mg d-amphetamine
    10 mg d-amphetamine dose given (double-blind) and behavioral tasks (EEfRT, PRT, ELT, CGT) administered.
  • Drug: 20mg d-amphetamine
    20 mg d-amphetamine dose given (double-blind) and behavioral tasks (EEfRT, PRT, ELT, CGT) administered.
  • Drug: Placebo
    Placebo dose given (double-blind) and behavioral tasks (EEfRT, PRT, ELT, CGT) administered.
Experimental
10 mg d-amphetamine, then 20mg d-amphetamine, then placebo
  • Drug: 10 mg d-amphetamine
    10 mg d-amphetamine dose given (double-blind) and behavioral tasks (EEfRT, PRT, ELT, CGT) administered.
  • Drug: 20mg d-amphetamine
    20 mg d-amphetamine dose given (double-blind) and behavioral tasks (EEfRT, PRT, ELT, CGT) administered.
  • Drug: Placebo
    Placebo dose given (double-blind) and behavioral tasks (EEfRT, PRT, ELT, CGT) administered.
Experimental
20 mg d-amphetamine, then 10mg d-amphetamine, then placebo
  • Drug: 10 mg d-amphetamine
    10 mg d-amphetamine dose given (double-blind) and behavioral tasks (EEfRT, PRT, ELT, CGT) administered.
  • Drug: 20mg d-amphetamine
    20 mg d-amphetamine dose given (double-blind) and behavioral tasks (EEfRT, PRT, ELT, CGT) administered.
  • Drug: Placebo
    Placebo dose given (double-blind) and behavioral tasks (EEfRT, PRT, ELT, CGT) administered.
Experimental
20 mg d-amphetamine, then placebo, then 10mg d-amphetamine
  • Drug: 10 mg d-amphetamine
    10 mg d-amphetamine dose given (double-blind) and behavioral tasks (EEfRT, PRT, ELT, CGT) administered.
  • Drug: 20mg d-amphetamine
    20 mg d-amphetamine dose given (double-blind) and behavioral tasks (EEfRT, PRT, ELT, CGT) administered.
  • Drug: Placebo
    Placebo dose given (double-blind) and behavioral tasks (EEfRT, PRT, ELT, CGT) administered.

More Details

Status
Completed
Sponsor
The University of Texas Health Science Center, Houston

Study Contact