Effects of Cannabidiol on Psychiatric Symptoms, Cognition, and Cannabis Consumption in Cannabis Users With Recent-Onset Psychosis

University of Maryland, Baltimore

Overview

A large proportion of people with a schizophrenia-spectrum disorder, especially in the early stages of the disease, regularly consume cannabis. Cannabis use is associated with poor prognostic outcome; however, there are no effective interventions targeted at reducing cannabis use or its deleterious effects in this population. The present trial is designed to test whether cannabidiol (CBD), a cannabinoid whose effects are in many ways antagonistic to those of Δ9-tetrahydrocannabinol (THC), can reduce psychiatric symptoms, cognitive deficits, and cannabis use in people with recent-onset psychosis who regularly consume cannabis.

This is a double-blind, randomized, placebo-controlled trial, evaluating the effects of a 12-week treatment course with CBD on psychiatric symptoms, cognition, and cannabis consumption in regular cannabis users with recent-onset psychosis. The study will be conducted at the Maryland Psychiatric Research Center (University of Maryland School of Medicine) and associated Early Intervention Programs in Baltimore, at the Sheppard Pratt Health System in Baltimore, and at the Psychosis Clinic of the University of California Los Angeles. The daily dose of CBD is 600 mg (p.o.), administered as adjunct medication. Any non-exclusionary antipsychotic, antidepressant, anxiolytic, or other medication prescribed prior to the trial will be continued. Participants may, but do not have to be taking conventional antipsychotic medication. The study will include 84 regular cannabis users with a schizophrenia-spectrum disorder who experienced their first psychotic episode within the last 5 years (90). Participants will be randomized 1:1 to either the CBD or the placebo group. Outcome measures include psychiatric symptoms, cognition, global functioning, and drug use, and will be assessed at baseline, and every 3 or 6 weeks thereafter (depending on the measure), until the end of treatment at 12 weeks. Outcome will be assessed again at a 3-month follow-up.

Study Type

INTERVENTIONAL

Allocation

RANDOMIZED

Purpose

TREATMENT

Masking

QUADRUPLE

Conditions

Schizophrenia Spectrum Disorders Cannabis Use

Interventions

Cannabidiol (CBD)DRUG

Participants receive a single dose of CBD (600 mg p.o.) per day for 12 weeks.

PlaceboDRUG

Participants receive a single daily dose of the oil vehicle used to dissolve CBD but without any active ingredient, in the same amount as the CBD group, for 12 weeks.

Eligibility

Sex: ALLMin age: 18 YearsMax age: 35 Years

Medical Language ↔ Plain English

Inclusion Criteria: * DSM-5 diagnosis of schizophrenia, schizoaffective disorder, schizophreniform disorder, and other specified or unspecified schizophrenia spectrum and other psychotic disorder. * Experienced a first psychotic episode within the last 5 years. * Self-reported cannabis use at least twice/week for at least the last 4 weeks. * THCCOOH serum levels of ≥ 5 ng/mL. * Total score ≥45 on the 18-item version of the Brief Psychiatric Rating Scale. * Able to give written informed consent. * Normal or corrected to normal vision. * If medicated, no change in psychiatric medication within the preceding 4 weeks, with no foreseeable changes. Exclusion Criteria: * DSM-5 diagnosis of Substance Use Disorder other that cannabis or nicotine within the last year (recreational use is not exclusionary). * Currently undergoing active treatment for Cannabis Use Disorder other than low-level (once/week or less) psychosocial intervention. * Uncontrolled hypertension (resting systolic BP above 150 or diastolic above 95 mm Hg). * Cardiovascular disease, such as history of myocardial infarction and ischemia, heart failure, angina, severe arrhythmias, or EKG abnormalities (Wolf-Parkinson-White syndrome, Complete left bundle branch block, PR interval \<120 ms or \>200 ms, Prolonged QT interval (corrected) \>500 ms, Cardiac arrhythmias as defined by PACs \>3 per min or PVCs \>1 per min). * History of or current neurological illness, such as stroke, seizure disorders, neurodegenerative diseases, or organic brain syndrome. * Intellectual disability. * Pregnant or lactating. * Diabetes. * Significant kidney or liver impairment. * Any chronic or severe infectious disease, including HIV and hepatitis. * Cancer. * Use of any barbiturates, diazepam, diltiazem, verapamil, protease inhibitors, any anticonvulsant medications (including valproate/valproic acid, lamotrigine, carbamazepine, and clobazam), glipizide, glyburide, warfarin, and cyclophosphamide/ ifosfamide, due to potential interaction with CBD at the metabolic level. * Suicidal ideation currently or within last 6 months (score of \>/= 3 on the Columbia Suicide Severity Rating Scale). * Less than the lower limit of normal hemoglobin and hematocrit at screening. * Elevated transaminase levels \>3 times the ULN, accompanied by elevations in bilirubin \>2 times the ULN.

Locations (3)

Semel Institute for Neuroscience and Human Behavior

Los Angeles, California, United States

Sheppard Pratt Health System

Baltimore, Maryland, United States

Maryland Psychiatric Research Center

Catonsville, Maryland, United States

Outcomes

Primary Outcomes

Change in Brief Psychiatric Rating Scale (BPRS) total score

The BPRS consists of 18 items assessing a broad range of psychiatric symptoms, including positive, negative, and affective symptoms. Each item is scored 1-7. Total scores are the sum of all items and range from 18 to 126, with larger values reflecting worse symptoms. The BPRS total score has been used widely in clinical studies of psychosis and has demonstrated reliability in assessing psychopathology across diverse psychosis populations.

Time frame: Baseline and 12 weeks

Change in MATRICS Consensus Cognitive Battery (MCCB) composite score

The MCCB is an FDA-approved assessment tool for trials of cognition-enhancing treatments in people with schizophrenia. The MCCB is comprised of the following domains: 1) Speed of Processing; 2) Attention/Vigilance; 3) Working Memory; 4) Verbal Learning; 5) Visual Learning; 6) Reasoning and Problem Solving; and 7) Social Cognition. The composite score is standardized to a T-scale (mean=50, standard deviation=10) based on healthy control normative data. Higher scores reflect better performance.

Time frame: Baseline and 12 weeks

Change in Serum concentrations of THCCOOH

THCCOOH is a THC metabolite and is used to quantify cannabis consumption. It has a long half-life (5-6 days) and thus provides a summary index of cannabis use within the last 1-2 weeks.

Time frame: Baseline and 12 weeks

Secondary Outcomes

Change in BPRS positive symptoms

The average of four BPRS key positive symptom items (conceptual disorganization, suspiciousness, unusual thought content, and hallucinatory behavior) will be analyzed as an index of antipsychotic effects of CBD. Possible values range from 1 to 7, with larger values reflecting more severe positive symptoms.

Time frame: Baseline and 12 weeks

Change in BPRS "Anxiety/Depression" subscale

Data from ClinicalTrials.gov

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