Imaging the Neurobiology of a Behavioral Treatment for Cocaine Dependence
Condition: Cocaine Dependence
MeSH terms: Cocaine-Related Disorders
Study type: Interventional

Summary: 
      The purpose of this study is to determine whether patients with the greatest loss of dopamine
      transmission due to cocaine dependence at pre-treatment PET and MRI scans will be those who
      fail to respond to substance abuse treatment. This study will also determine whether patients
      who do respond to treatment will experience a recovery of dopamine function. This study
      includes free brain imaging and behavioral intervention. Compensation provided for the brain
      scans.
    

Detailed description: 
      Previous studies have shown that cocaine dependence is associated with a decrease in dopamine
      release in response to a psychostimulant challenge. We have recently completed a study
      demonstrating that this loss of pre-synaptic dopamine function is associated with the choice
      to self-administer cocaine in the presence of an alternative reinforcer. This finding
      consistent with animal models of reinforcement and which show that dopamine transmission
      serves to modulate reward based behavior, and in this case, allows for a more adaptive
      response to be made in the presence of a competing reinforcer.

      The previous study was performed in non-treatment seeking cocaine dependent subjects using an
      inpatient laboratory model to measure the choice for cocaine. Thus, the goal of the present
      proposal is to investigate this association in a more realistic setting where cocaine
      dependent out patients face the choice between using cocaine and the alternative reinforcers
      presented to them in a therapeutic setting. The Community Reinforcement Approach with voucher
      incentives is a treatment for cocaine dependence that has been shown success in a number of
      controlled studies. Since the basis of this therapy is to reduce the reinforcing value of
      cocaine by increasing the density of alternative, healthy reinforcers, we have chosen to
      correlate outcome from this treatment with measures of presynaptic dopamine function. We
      propose to scan cocaine dependent patients with [11C]raclopride and oral methylphenidate in
      order to measure dopamine release. Patients will be scanned before treatment and at 12 weeks
      into therapy. We predict that the patients with the greatest loss of dopamine transmission at
      the pre-treatment scan will be those who fail to respond to treatment. Furthermore, we
      hypothesize that the patients who do respond to treatment will experience a recovery of
      dopamine function, measured at the post-treatment scan.

      In addition, subjects enrolled in this study will undergo functional Magnetic Resonance
      Imaging (fMRI) and spectroscopy studies in order to asses differences in neuronal integrity,
      learning, and impulse control.
    

Intervention name(s): Community Reinforcement Approach
Intervention type(s): Behavioral
Intervention description(s): Community Reinforcement Approach (CRA): The community reinforcement treatment program will be carried out in accordance with NIDA's therapy manual (13).During weeks 13 through 24, patients will meet once per week with their therapists. Sessions will focus on promoting continued change in the life areas addressed in the first 12 weeks of treatment or new components are added as needed.
Allocation: Non-Randomized
Intervention model: Parallel Assignment
Masking: None (Open Label)
Primary purpose: Treatment
Keywords: cocaine dependence