Automatic Versus Evaluative Components of Cue Reactivity
Condition: Drug Dependence
MeSH terms: Substance-Related Disorders
Study type: Observational

Summary: 
      Background:

      - Relapse to drug abuse often happens in the presence of stimuli that are associated with
      previous drug use, also known as cues. Drug-taking behavior appears to be partly controlled
      by such cues. Some research suggests that cue-induced craving states are responsible for drug
      use and relapse, but other research suggests that cues can control drug taking without
      conscious craving or even awareness. Researchers are interested in using functional magnetic
      resonance imaging (fMRI) to study how individuals respond to drug-related cues and how these
      cues affect craving on a conscious or unconscious level.

      Objectives:

      - To determine how drug-related stimuli (cues) affect thinking, information processing, and
      body reactions in current drug users.

      Eligibility:

      - Individuals between 18 and 50 years of age who are dependent on either tobacco or
      crack-cocaine, or are healthy volunteers who are not dependent on either drug.

      Design:

        -  The study will require two sessions, a training session and a testing session, that will
           take place within 48 hours of each other. Between the two test sessions, participants
           may not consume alcohol, tobacco, or illegal drugs, and must restrict caffeine
           consumption.

        -  During the first session, participants will complete questionnaires about
           tobacco/cocaine use and craving, and will be trained on the tasks to be performed in the
           MRI scanner.

        -  During the second session, participants will perform concentration tasks and look at
           pictures, some of which will be tobacco/cocaine related. Body reactions such as heart
           rate, pupil dilation, and sweating will be measured during this session. Some
           participants will have actual MRI scanning, while others will have mock MRI scanning.

        -  After the MRI session, participants will complete questionnaires about craving and
           responses to the scan.
    

Detailed description: 
      Relapse to drug abuse often happens in the presence of stimuli that are associated with
      previous drug-use, and drug-taking behavior appears to be partly controlled by such cues.
      While some theories postulate that such facilitation is mediated by cue-induced craving
      states, others hypothesize that the underlying processes are highly automatized and can
      happen without conscious control or even awareness. One way to approach psychological
      mechanisms of cue reactivity is to measure disruption of ongoing mental activity by
      drug-related material in dependent individuals while manipulating the degree to which
      cognitive evaluative processes can unfold. Craving measurement under these conditions can
      elucidate its relationship with automatic processing versus conscious evaluation of drug
      cues. Autonomic and neural correlates can be identified by concomitant psychophysiological
      and fMRI recording. Results from these studies will shed light on the role of spontaneous
      automatic reactions versus cognitive evaluation for different measures of cue reactivity. By
      helping to elucidate the psychological mechanisms and neurobiological basis of drug-cue
      reactivity in dependent individuals, this may have substantial implications for the
      understanding of mechanisms and treatment of drug dependence. Thus, while there are no direct
      benefits to subjects participating in these experiments, the results may benefit the health
      of society. MRI-related risks to subjects (injury from metal implants, claustrophobia,
      temporary deafness due to the loud banging noises) will be minimized by prescreening and
      providing earplugs. Drug-related cues may induce acute craving; subjects will be dismissed
      only after craving levels have returned to baseline.
    

Keywords: Nicotine; Cocaine; N-Back; Craving; Dependence