The Effects of Cannabis Use in People With Schizophrenia on Clinical, Neuropsychological and Physiological Phenotypes

• Status: Terminated
• Trial end date: 2011-05-01
• Target enrollment: 0
• Participant gender: All

Summary

Approximately 25% of people with schizophrenia abuse marijuana. These people may be using marijuana to self-medicate symptoms such as hallucinations (hearing or seeing things that are not heard or seen by others) or delusions (false beliefs i.e. people are harassing or persecuting them) or the depressed and anxious feelings brought on by these symptoms. Currently, it is unknown whether marijuana makes schizophrenia better or worse. Marijuana intoxication in people without schizophrenia generally causes decreased recall of words, may decrease reaction time and decrease inhibition. Additionally, marijuana may cause distractibility as demonstrated by difficulty keeping their eyes on a moving target and difficulty inhibiting their response to repetitive tones. However, marijuana may have different effects in schizophrenia. Receptors for cannabis (marijuana) are concentrated in the brain and maladjustment of the cannabinoid system may be associated with the difficulty in thinking found in schizophrenia. The proposed research project examines if clinical symptoms, learning, memory, inhibition and distractibility are improved or made worse by the acute ingestion of tetrahydrocannabinol (THC).

• Phase: Phase 1/Phase 2
• Accepts Healthy Volunteers?: No

Details

• Lead Sponsor: University of Colorado, Denver
• Collaborator: National Alliance for Research on Schizophrenia and Depression
• Treatments: Dronabinol

Criteria

Inclusion Criteria:

• Male and females

• 18 and 50 years of age

• Diagnosis of schizophrenia

• Chronic cannabis users who have used for at least 1 year

• Using cannabis at least once weekly

• Currently being treated with antipsychotic medication

• Must be on a the same dose of antipsychotic medication for at least 3 months.

• Females of childbearing potential must use an adequate form of birth control while participating.

• Participants will be required to have blood pressures greater than 90/60 and less than 140/90.

Exclusion Criteria:

• Use of illicit drugs other than cannabis

• Any psychiatric hospitalizations within 3 months

• pregnancy in females

• taking clozapine