Investigating the Neural Correlates of Cognitive Function in Psychosis Patients and Non-Psychiatric Controls With Cannabis Use

Launched by DOUGLAS MENTAL HEALTH UNIVERSITY INSTITUTE · Jun 30, 2022

Keywords

ClinConnect Summary

This clinical trial is studying how cannabis use affects thinking and memory in people with psychotic disorders, such as schizophrenia, compared to individuals without mental health issues who also use cannabis. The researchers want to understand what happens in the brain when people with psychosis stop using cannabis for 28 days. Participants will be divided into two groups: one that will stop using cannabis and another that will continue using it. They will undergo brain scans at the beginning of the study and again after the 28-day period to see if there are any changes related to their cognitive function.

To be eligible for this study, participants must be over 18 years old, have been heavy cannabis users for at least six months, and either have a psychotic disorder (for the psychosis group) or no major mental health issues (for the control group). Participants should also be stable on their medications if they are in the psychotic disorder group. During the study, participants can expect to attend appointments for brain scans and assessments of their cognitive abilities. This research is important because it may help develop better treatments and support for those struggling with cannabis use and cognitive difficulties related to psychosis.

Gender

ALL

Eligibility criteria

• Inclusion Criteria:
• • Able to provide informed consent in English or French
• • Heavy cannabis use (defined as weekly cannabis use for at six months) and/or DSM-5 diagnosis of CUD
• • Have a Full-Scale IQ ≥ 75
• • Meet DSM-5 criteria for a psychotic disorder (psychosis patient arm only)
• • Be an outpatient receiving a stable dose of medication(s) for at least two months (psychosis patient arm only)
• • Clinically stable (as measured by the PANSS-6, total score \<30) (psychosis patient arm only)
• Exclusion Criteria:
• • current SUD (other than CUD)
• • MRI contraindications
• • Positive urine screen for psychoactive substances other than cannabis, nicotine, or caffeine
• • Current suicidal or homicidal ideation
• • Head injury requiring hospitalization or loss of consciousness \> 5 minutes
• • Current medical diseases that requires hospitalization or regular monitoring
• • Being pregnant
• • DSM-5 Axis 1 diagnosis (other than CUD) (non-psychiatric controls only)
• • Taking psychotropic medication