Cannabis, Schizophrenia and Reward: Self-Medication and Agonist Treatment?

• Status: Completed
• Trial end date: 2021-09-18
• Target enrollment: 0
• Participant gender: All

Summary

In this translational research proposal, based on our formulation, we seek to confirm and expand upon data obtained in our pilot study suggesting that cannabis and the cannabinoid agonist dronabinol, given in low dose to patients with schizophrenia and co-occurring cannabis use disorder, will in fact ameliorate the brain reward circuit dysregulation in these patients and, thereby, provide evidence in support of the role of cannabis as a "self-medication" agent for them.

• Phase: Phase 1
• Accepts Healthy Volunteers?: Accepts Healthy Volunteers

Details

• Lead Sponsor: Dartmouth-Hitchcock Medical Center
• Collaborators: Columbia University; Harvard Medical School; Harvard Medical School (HMS and HSDM); Massachusetts General Hospital; Massachusetts Institute of Technology; Nathan Kline Institute for Psychiatric Research; National Institute on Drug Abuse (NIDA); University of Vermont
• Treatments: Dronabinol

Criteria

Inclusion Criteria:

Groups 1-3 Participants with schizophrenia and a cannabis use disorder

1. Ages 18 - 55 years

2. Diagnosis of schizophrenia

3. Diagnosis of cannabis abuse or dependence

4. Use of cannabis within the month prior to screening

5. Willing to remain abstinent for the 14 days before the baseline assessments and throughout the two scans.

6. Psychiatrically stable

7. Treated with a stable dose of an antipsychotic medication (except clozapine) for the past month

8. Not seeking treatment for their cannabis use disorder.

Group 4 - Control participants with schizophrenia

1. Ages 18 - 55 years

2. Diagnosis of schizophrenia

3. Willing to remain abstinent as described above

4. Psychiatrically stable

5. Treated with a stable dose of an antipsychotic medication (except clozapine) for the past month

Groups 5-7 - Control participants with cannabis use disorder

1. Ages 18 - 55 years

2. Diagnosis of cannabis abuse or dependence

3. Use of cannabis within the month prior to screening

4. Willing to remain abstinent as described above

5. Not seeking treatment for their cannabis use disorder.

Group 8 - Healthy control participants

1. Ages 18 - 55 years

2. Willing to remain abstinent as described above

Exclusion criteria:

Groups 1-3 with schizophrenia and a cannabis use disorder

1. Positive symptoms of psychosis (> 4 [moderate]) on any item of the Positive and Negative Syndrome Scale psychosis subscale (once abstinent) except for the hallucination item. We will exclude for a rating > 5 for this item.

2. Cocaine/stimulant use disorder

3. Pharmacological treatment for addiction

4. Mental retardation

5. History of head injury

6. Metal objects within the body that would contraindicate and MRI

7. Pregnancy or currently nursing

8. Uncontrolled medical condition

9. Taking clozapine

10. Any condition that would contraindicate use of cannabis or dronabinol.

11. History of a seizure disorder

Group 4 - Control participants with schizophrenia

1. Positive symptoms of psychosis (> 4 [moderate]) on any item of the Positive and Negative Syndrome Scale psychosis subscale (once abstinent) except for the hallucination item. We will exclude for a rating > 5 for this item.

2. Any history of a substance use disorder other than nicotine

3. Pharmacological treatment for addiction

4. Mental retardation

5. History of head injury

6. Metal objects within the body that would contraindicate and MRI

7. Pregnancy or currently nursing

8. Uncontrolled medical condition

9. Taking clozapine

Groups 5-7 - Control participants with cannabis use disorder

1. Axis I psychiatric diagnosis other than a cannabis use disorder

2. Taking any psychotropic medication

3. Pharmacological treatment for addiction

4. Mental retardation

5. History of head injury

6. Metal objects within the body that would contraindicate and MRI

7. Pregnancy or currently nursing

8. Uncontrolled medical condition

9. History of a seizure disorder

Group 8 - Healthy control participants

1. Any Axis I psychiatric diagnosis

2. Taking any psychotropic medication

3. Pharmacological treatment for addiction

4. Mental retardation

5. History of head injury

6. Metal objects within the body that would contraindicate and MRI

7. Pregnancy or currently nursing

8. Uncontrolled medical condition

9. Current tobacco smokers