Effects of Cannabidiol (CBD) Versus Placebo as an Adjunct to Treatment in Early Psychosis

  • End date
    Jun 30, 2023
  • participants needed
  • sponsor
    University of California, San Diego
Updated on 22 June 2021


This is an outpatient, single center, between-group, double blind, placebo controlled design. Approximately 120 adolescents and adult patients will be randomized to either have their treatment augmented with Cannabidiol Oral Solution (CBD) or with a matching CBD placebo for 8 weeks. The study will examine CBD as an augmentation strategy in early psychosis. It is hypothesized that CBD will improve symptoms, neurocognition, markers of inflammation and eating behaviors. Importantly, moderators and mediators of the CBD effects will be explored.


Participants will be randomly assigned in a 1:1 ratio to receive CBD or matching Placebo as an add-on to antipsychotic medication in an 8 week double blind trial. In this study, Cannabidiol Oral Solution (CBD) product will be used. This product is manufactured and supplied by GW Pharmaceuticals. The formulation is a 100 mg/mL solution. The CBD compound will be dosed at 1000mg/day administered in two divided doses. The dose of CBD was selected based on previous controlled trials that demonstrate the efficacy of CBD in patients with schizophrenia.

The maximum duration of the study from screening to follow up of outcomes and adverse events will be approximately 8 weeks. Participants will receive either the CBD or placebo within this eight.weeks and will also complete pre-treatment, midpoint (week 4) and post-treatment testing (week 8).

Condition Early Psychosis
Treatment Cannabidiol Oral Solution
Clinical Study IdentifierNCT04411225
SponsorUniversity of California, San Diego
Last Modified on22 June 2021


Yes No Not Sure

Inclusion Criteria

First episode psychosis (onset within the last 2 years) or attenuated psychosis syndrome (APS), stabilized with treatment for at least 8 weeks prior to initiating the trial consistent with the FDA-NIMH-MATRICS guidelines for clinical trial design for clinical enhancing drugs
Clinically stable and in a nonacute phase of their illness for at least 2 months, First episode psychosis participants will have been maintained on current antipsychotic for at least 6 weeks, with no change in antipsychotic dose for the previous 4 weeks while APS participants will be on the same treatment regimen (psychosocial or pharmacologic) for 4 weeks
Exhibit no more than moderate levels of positive symptoms (defined by ratings of 4) on PANSS items P1 (delusions), P2 (conceptual disorganization), P3 (hallucinatory behavior), P5 (grandiosity), P6 (suspiciousness), and G8 (unusual thought content)
No more than a minimal level of depressive symptoms as assessed by the Calgary Depression Scale for Schizophrenia (CDSS)
Acceptable diagnoses will include APS, Psychosis NOS, Schizophreniform, Schizophrenia, and Schizoaffective per the Structured Clinical Interview for DSM-V

Exclusion Criteria

Concomitant medical or neurological illness
Significant head injury
Current substance abuse or positive toxicology screen for drugs including THC and CBD as detected by urine and blood samples
Impaired intellectual functioning IQ<80; however those with an IQ i the 75-79 range will be include if WRAT reading > 85 suggesting higher premorbid IQ
High suicidal risk assessed by the The Columbia-Suicide Severity Rating Scale (C-SSRS)42
Pregnant women and those who do not agree to avoid becoming pregnant
Patients requiring treatment with Azelastine, Azelastine; Fluticasone, Dronabinol, Valproic Acid, or Divalproex Sodium
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