The Neuroeconomics of Behavioral Therapies for Adolescent Substance Abuse
Condition: Adolescent Substance Use
MeSH terms: Substance-Related Disorders
Study type: Observational

Summary: 
      This study will measure the brain activity of adolescent substance abusers while they make
      decisions about their preferences to receive smaller, immediate rewards versus larger delayed
      rewards. The investigators expect that patterns of brain activity while engaged in this
      decision making task will predict response to treatment among adolescent substance users. The
      investigators expect to use the results of this study to develop more effective treatments
      for adolescent substance abuse
    

Detailed description: 
      Little is known about the role of adolescent neurodevelopment in adolescent substance abuse
      treatment outcomes. The development and evaluation of adolescent substance abuse treatments
      rarely includes consideration of varying cognitive capacities and their neural
      representations as determinants of individual variation in treatment response. This proposed
      R21 project would address this gap by identifying associations among decision making,
      task-related neural processing, and treatment outcome among adolescents participating/have
      participated in two randomized clinical trials for adolescent substance abuse. Increasing our
      understanding of neural processes that underlie decision making in adolescent marijuana and
      alcohol users would inform the development of future intervention and prevention efforts.

      This complementary project draws subjects from two studies investigating
      contingency-management (CM) based treatments "Behavioral Treatment of Adolescent Marijuana
      Abuse" (DA015186), and "Family Based Contingency Management for Adolescent Alcohol Abuse"
      (AA016917). Both trials compare a unique CM intervention that involves an abstinence-based
      reinforcement program to a standard, state of the art cognitive behavioral intervention.
      Analyses would be performed separately for the two samples, with hypotheses tested first
      using the Marijuana sample, and assessed for replication/specificity using the Alcohol
      sample. The proposed project would explore novel neurobiological predictors of response to CM
      interventions.

      Adolescents recruited into the Marijuana Trial (n=69; 23 per treatment arm) and the Alcohol
      Trial (n=54; 27 per treatment arm) during the period of this R21 project would participate in
      a single neuroimaging session as soon after the intake session as possible, within 7 to 30
      days. During the neuroimaging session, adolescents would make intertemporal choice decisions
      in a Delay Discounting task regarding gains of $100 and $1,000. Preliminary data from the
      Marijuana trial demonstrates significant association between performance on this behavioral
      delay discounting task and abstinence achieved during treatment over and above the
      significant effect of treatment condition. The investigators seek to understand the neural
      processes that underlie performance on this laboratory task, and the degree to which
      variation in these neural processes relates to and predicts adolescent substance abuse
      treatment outcomes. The conceptual framework for the proposed project is based on the
      neuroeconomics of addiction in general, and the competing neural systems hypothesis in
      particular (Bechara, 2005a; Bickel, et al., 2007; Daw, et al., 2005; Jentsch & Taylor, 1999).
      This behavioral choice hypothesis postulates a biased competition between an "impulsive" (or
      ''reflexive") neural system (including the striatum, amygdala, ventral pallidum, and related
      structures) and the "executive" (or "reflective") neural system (including the prefrontal
      cortex) in understanding patterns of suboptimal decision making among substance-dependent
      individuals. An overarching hypothesis is that differing responses to distinct treatment
      approaches (CM vs. CBT) are partially determined by the pattern of activation or functional
      connectivity within and across these competing neural systems. These project hypotheses would
      be tested by the following specific aims:

      Primary Aims:

        -  Determine the degree to which performance on a laboratory delay discounting task
           correlates with activity in impulsive and/or executive neural systems.

        -  Determine the degree to which performance on a laboratory delay discounting task and
           neural processing predict adolescent substance abuse treatment outcome over and above
           the effects of treatment condition.

      Secondary Aim:

        -  Explore interactions between response to CM and delay discounting-related neural
           processing.

      In summary, this proposed exploratory/developmental project would importantly contribute to
      the understanding of the role of neural processing in adolescent substance-abuse treatment
      processes and outcome. Specifically, this study has the potential to reveal relations among
      decision making, neural processing, and treatment outcomes, including the role of patterns of
      neural activation on response to contingency management among adolescent substance abusers.
      Results will have implications for future research on adolescent neurodevelopment and
      adolescent substance abuse treatment. The potential to use neuroscience findings to better
      understand and improve treatment outcomes in substance-abusing adolescents will have strong
      public health impact.
    

Observational model: Family-Based
Time perspective: Prospective
Sampling method: Non-Probability Sample
Study population: 
        Adolescents recruited into the Marijuana Trial and the Alcohol Trial during the period of
        the R21 project would participate in a single neuroimaging session as soon after the intake
        session as possible.