Using Cannabidiol to Treat Early Psychosis

Effects of Cannabidiol (CBD) Versus Placebo as an Adjunct to Treatment in Early Psychosis: Understanding the Mechanism and Mediators of Action

Phase 3 Interventional University of California, San Diego · NCT04411225

This study is testing if adding Cannabidiol (CBD) to the usual treatment can help young people and adults with early psychosis feel better and improve their symptoms.

Quick facts

PhasePhase 3
Study typeInterventional
Enrollment120 (estimated)
Ages16 Years to 30 Years
SexAll
SponsorUniversity of California, San Diego Academic / other
Locations2 sites (La Jolla, California and 1 other locations)
Trial IDNCT04411225 on ClinicalTrials.gov

What this trial studies

This clinical trial investigates the effects of Cannabidiol (CBD) as an adjunct treatment for early psychosis in adolescents and adults. Approximately 120 participants will be randomly assigned to receive either CBD or a placebo for 8 weeks, alongside their existing antipsychotic medication. The study aims to assess improvements in symptoms, neurocognition, inflammation markers, and eating behaviors, while also exploring the factors that may influence the effects of CBD. Participants will undergo evaluations at the start, midpoint, and end of the treatment period.

Who should consider this trial

Good fit: Ideal candidates include adolescents and adults experiencing their first episode of psychosis or attenuated psychosis syndrome, who are clinically stable and on antipsychotic treatment.

Not a fit: Patients with severe depressive symptoms or those not stabilized on their current antipsychotic regimen may not benefit from this study.

Why it matters

Potential benefit: If successful, this study could provide a new adjunctive treatment option for individuals experiencing early psychosis.

How similar studies have performed: Previous studies have shown promising results for CBD in treating symptoms of schizophrenia, suggesting potential success for this approach.

Eligibility criteria

Show full inclusion / exclusion criteria
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;
* 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

Where this trial is running

La Jolla, California and 1 other locations

Study contacts

How to participate

  1. Review the eligibility criteria above with your treating physician.
  2. Visit the official trial page on ClinicalTrials.gov for the most current contact information and recruitment status.
  3. Contact the listed study coordinator or principal investigator to request pre-screening. Pre-screening is free and never obligates you to enroll.
Conditions Early Psychosis
Last reviewed 2026-06-13 by the Find a Trial editorial team. Information on this page is for educational purposes and is not medical advice. Always consult qualified healthcare professionals about clinical trial participation.