for people ages 16-30 (full criteria)
at La Jolla, California and other locations
study started
completion around
Principal Investigator
by Kristin Cadenhead, MD
Headshot of Kristin Cadenhead
Kristin Cadenhead



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.

Official Title

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


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).


Early Psychosis, Psychotic Disorders, Mental Disorders, Cannabidiol, Cannabidiol oral solution, Cannabidiol Augmentation


You can join if…

Open to people ages 16-30

  • 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.

You CAN'T join if...

  • 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


  • UC San Diego accepting new patients
    La Jolla California 92093 United States
  • University of California, San Diego accepting new patients
    San Diego California 92093 United States

Lead Scientist at UCSD

  • Kristin Cadenhead, MD
    Dr. Kristin Cadenhead a Professor of Psychiatry at University of California San Diego and an attending physician at the UCSD Medical Center. She served as Residency Training Director for the Department of Psychiatry from 2017-2022.


accepting new patients
Start Date
Completion Date
University of California, San Diego
Phase 3 research study
Study Type
Expecting 120 study participants
Last Updated