Assessment of Cannabis Craving in Schizophrenia Using Virtual Reality
Condition: Cannabis Use
MeSH terms: Marijuana Abuse; Schizophrenia
Study type: Observational

Summary: 
      Background:

      - Individuals with schizophrenia or schizoaffective disorders have a high prevalence of
      cannabis use. Understanding some of the environmental factors that maintain cannabis use,
      such as socially triggered cravings, is a critical step in improving treatment for cannabis
      dependence. In recent years, virtual reality has been studied to determine whether it can be
      used to induce craving by using life-like cue settings. Researchers are interested in using
      virtual reality systems to study cannabis cravings in individuals with schizophrenia.

      Objectives:

      - To determine if virtual reality cues will elicit cannabis craving in persons with
      schizophrenia who have a history of cannabis use.

      Eligibility:

      - Individuals between 18 and 50 years of age who have been diagnosed with schizophrenia or
      schizoaffective disorders, are on a stable antipsychotic medication, and who have a lifetime
      history of at least 50 cannabis uses and average cannabis use of once per month.

      Design:

        -  This study involves an initial screening visit, a study visit, and a followup visit.

        -  Participants will be screened with a medical history and physical examination, and will
           complete questionnaires about their history of marijuana and other drug use.
           Participants will also learn how to use the virtual reality equipment at this visit.

        -  During the study visit, participants will respond to marijuana cues using the virtual
           reality system while researchers monitor their heart rate, blood pressure, and sweat
           levels.

        -  At the followup visit, participants will complete questionnaires about their mood and
           any cravings for marijuana.
    

Detailed description: 
      Objective: The use of cannabis is prevalent in people with schizophrenia, and has been linked
      both to onset of illness and worsening of symptoms. Craving in persons with schizophrenia who
      use cannabis has not been widely studied. The occurrence of craving may lead to relapse in
      substance use disorders. Therefore, craving paradigms in people with schizophrenia need to be
      optimized in order to test new treatments on craving measures in this population. Thus, the
      purpose of this study is to determine the feasibility and effects of virtual reality cues on
      craving intensity for cannabis in patients with schizophrenia

      Study population: We will enroll 25 persons with a DSM IV diagnosis of schizophrenia who have
      a lifetime history of at least 50 lifetime uses of cannabis and cannabis use an average of at
      least once per month (or, if inpatients, average use of once per month prior to
      hospitalization) with a goal of 16 completers.

      Design: This study uses a comparison-controlled, within-subject design. All subjects will
      undergo a baseline assessment and acclimation period and then participate in an experimental
      condition in which four cues will be presented in separate rooms in the VR program. These
      include two cannabis cues and two neutral cues in four different rooms. A follow up session
      for craving and symptom assessments will occur one week after the experimental session.

      Outcome Measures:

      At the end of each of the four cues, the Cannabis Craving Scale (CCVAS), Cannabis Attention
      scale (CAS), the Marijuana Craving Questionnaire-Short Form (MCQ-SF), and a visual analog
      cigarette craving item will be administered to measure craving during the virtual reality
      session. The CCVAS and CAS will be projected into the VR environment and participants will
      respond via hand controller. The MCQ-SF will also be administered, as well as the Mood form ,
      to assess mood, at baseline as well as at the end of each of the 4 cues. Before and after the
      experimental session participants will also be rated on the Brief Psychiatric Rating Scale
      (BPRS), Schedule for the Assessment of Negative Symptoms (SANS), side effects, and the
      State-Trait Anxiety Inventory (STAI). The Immersion Questionnaire and Imagery Realism
      Presence Questionnaire (PQ) will be given at the conclusion of the experimental session.
      Before and after the session, as well as during the experiment participants will be monitored
      for physiological reactivity (heart rate, blood pressure, and skin conductance response) to
      cues of cannabis use as well as neutral cues measured.
    

Time perspective: Prospective
Keywords: Virtual Reality; Schizophrenia; Cannabis; Assessment; Craving