Cannabis and Schizophrenia: Self-Medication and Agonist Treatment
Condition: Schizophrenia; Dual Diagnosis; Schizoaffective Disorder; Psychotic Disorder; Cannabis Use Disorder
MeSH terms: Marijuana Abuse; Schizophrenia; Psychotic Disorders
Intervention: Dronabinol; Cannabis
Intervention description: Dronabinol 10 mg or 15 mg; Cannabis cigarette
Intervention MeSH terms: Dronabinol
Phase: Phase 1
Study type: Interventional
Primary purpose: Basic Science
Allocation: Randomized
Intervention model: Parallel Assignment
Masking: Quadruple (Participant, Care Provider, Investigator, Outcomes Assessor)
Enrollment: 12.0
Sex: All
Minimum age: 18 Years
Maximum age: 50 Years
Healthy volunteers: Accepts Healthy Volunteers
Keywords: Dronabinol; Schizophrenia; Dual Diagnosis; Substance Abuse; Cannabis Use Disorder

Summary:

      The first aim of this study is to determine whether a brain reward center (BRC) deficiency in
      patients with schizophrenia (SCZ) and cannabis use disorder (CUD) will be normalized when
      patients are given cannabis or dronabinol. The second aim will serve to further assess the
      effects of dronabinol on symptoms and medication side effects in this population.
    

Eligibility criteria:

        Inclusion Criteria:

        Inclusion criteria for study subjects (dual diagnosis patients):

          -  Age 18-50;

          -  Diagnosis of schizophrenia or schizoaffective disorder (by SCID)

          -  Diagnosis of current cannabis abuse or dependence (by SCID);

          -  Recent use of cannabis (within the past month on Timeline Follow-Back);

          -  Stability on antipsychotic medication for past 1 month);

          -  Outpatient status for past 3 months;

          -  Willing and able to participate as demonstrated by a signed informed consent document.

        Inclusion criteria for normal control subjects:

          -  Age 18-50;

          -  Willing to participate as demonstrated by a signed informed consent document

        Exclusion Criteria:

        Exclusion criteria for study subjects (dual diagnosis patients):

          -  PANSS subscale for positive symptoms of psychosis item > 3 [moderate] on Day 15 (once
             they are abstinent from cannabis);

          -  Cocaine/stimulant use disorder;

          -  Pharmacological treatment for addiction (e.g., disulfiram, naltrexone, acamprosate,
             topiramate); Mental retardation;

          -  Pregnancy or currently nursing;

          -  Uncontrolled serious medical condition;

          -  Seizure disorder

          -  Seeking treatment to limit their cannabis use

          -  Taking clozapine

        Additional Exclusion criteria for Main Study patients only:

          -  Claustrophobia prohibiting scanning

          -  History of head injury with period of unconsciousness;

          -  Metal objects within the body;

          -  Taking antipsychotic other than risperidone or first generation antipsychotic as main
             treatment

          -  Previous participation in the Pilot Dose Finding Study

        Exclusion criteria for normal control subjects:

          -  Axis I or Axis II psychiatric diagnosis (including substance use disorder) based on
             SCID

          -  Mental retardation;

          -  History of head injury with period of unconsciousness;

          -  Metal objects within the body;

          -  Pregnancy or currently nursing;

          -  Uncontrolled serious medical condition;

          -  Current tobacco smokers. Note: We exclude current tobacco smoking (but not a history
             of smoking) in the normal control subjects since the fact of cigarette smoking could
             select subjects with a dysregulated BRC as a basis for their continued cigarette
             smoking in the face of social conventions toward non-smoking.