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NCT Number: NCT04411225

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

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.

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Key information

Conditions

Early Psychosis Mental Disorders Psychotic Disorders Schizophrenia Spectrum and Other Psychotic Disorders

Age range

16 year–30 year

Sex eligibility

All sexes

Study type

Interventional

Phase

Phase 3

Primary location

UC San Diego, La Jolla, California, United States

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About this study

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).

Who can participate

Healthy volunteers accepted: No

Only the study team can determine whether someone qualifies for participation.

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

Treatment and study plan

Cannabidiol Oral Solution

Drug

Both the active drug (cannabidiol) and placebo will be in oral solution.

Other names: Placebo

Primary outcomes

  1. Positive and Negative Symptoms of Psychosis

    Time frame: Week 7

    Psychotic symptoms will be assessed with The Positive and negative psychotic syndrome scale (PANSS). This scale provides a summary score of all positive symptoms and all negative symptoms in participants who are already diagnosed with a psychotic disorder. The total score ranges from 30 to 210 with a higher score representing more symptoms.

  2. Neurocognition

    Time frame: week 7

    A Global Cognition Score will be assessed with Measurement and Treatment Research in Cognition in Schizophrenia (MATRICS) Consensus Cognitive Battery (MCCB) in all subjects.The Global Cognitive Score is a composite of the Z scores across the different cognitive domains in the MCCB. The range of scores is -1 to +1. Positive scores represent better cognitive functioning.

  3. Prodromal Symptoms

    Time frame: Week 7

    The Scale of Prodromal Symptoms (SOPS) is part of the Structured Interview for Prodromal Syndromes (SIPS) diagnostic interview. This scale will be used to assess subsyndromal psychotic symptoms in participants who are diagnosed as Clinical High Risk for Psychosis. Positive and Negative Symptoms will be assessed as summary scores of all positive or negative items The minimum score on the SOPS total is 0 and Maximum is 24. A higher score represents more symptoms.

  4. General Symptoms

    Time frame: week 7

    The Brief Psychiatric Rating Scale (BPRS) will be used as an assessment of overall symptom ratings with a total score in all subjects. The minimum score is 24 and maximum is 168. A higher score represents more symptoms.

  5. Clinical Global Impression Scale (CGI-S)

    Time frame: Week 7

    The CGI-S will provide a global psychopathology score for all subjects. The Clinical Global Impression - Severity scale (CGI-S) is a 7-point scale that requires the clinician to rate the severity of the patient's illness at the time of assessment, relative to the clinician's past experience with patients who have the same diagnosis. A "1" is considered normal while a "7" is extremely ill.

Secondary outcomes

  1. Peripheral Biomarkers of Inflammation

    Time frame: week 7

    Panel of chemokines and cytokines expressed as "Mean Concentration Value". The minimum and maximum value for each measure between 0 and 40,280. In general higher values represent greater immune activation.

    Cytokines:

    Interferon-gamma, Interleukin-1, Interleukin-6, Interleukin-10, Interleukin-12p70, Tumor Necrosis Factor- alpha,

    Chemokines:

    Eotaxin-1, Eotaxin-3, Fracktalkine, Interleukin-8, Interferon Gamma-Induced Protein-10, Monocyte Chemotactic Protein-1, Macrophage-Derived Chemokine, Macrophage Inflammatory Protein-1a, Macrophage Inflammatory Protein-1b, Thymus and Activation Regulated Chemokine,

    Other:

    Brain Derived Neurotropic Factor

  2. Cortisol

    Time frame: 7 weeks

    AM Salivary Cortisol is normally in the range of 100-750 ng/dL. Higher levels are thought to represent a greater stress response.

Other outcomes

  1. Eating Behavior

    Time frame: 7 weeks

    Three Factor Eating Questionnaire will be used to query about eating behavior in different categories using total score: cognitive dietary restraint, disinhibition, and susceptibility to hunger. Each score is converted to a scaled score from 0 to 100 with the higher score representing more restraint, more dishinibition and less hunger.

  2. Body Mass Index

    Time frame: 7 weeks

    Height and weight will be used to calculate Body Mass Index, a ratio of height and weight. Normal BMI is considered 18.5 to 25.

  3. Cholesterol

    Time frame: Baseline and week 7

    serum will be drawn to measure total cholesterol, low density and high density lipoproteins along with Triglycerides. All are measured in mg/dL. Normal values include Total Cholesterol <=199, Triglycerides 30 - 149, High Density Lipoprotein 40-59, Low Density Lipoprotein <=129.

  4. Electrophysiology Mismatch Negativity

    Time frame: Baseline and week 7

    Mismatch Negativity (MMN) measured in an event related potential paradigm. The value is expressed in micorvolts and represents the difference in response to standard versus mismatch stimuli measure at 100 milliseconds post stimuli. The mismatch negativity value varies between 0 and -6 microvolts with greater negative numbers representing greater mismatch negativity. The MMN is thought primarily to reflect the activity of sensory memory, with, at most, moderate influences of higher-level cognitive processes, such as attention.

  5. Electrophysiology - Prepulse Inhibition

    Time frame: Baseline and week 7

    Prepulse Inhibition of the human startle response. Prepulse Inhibition is expressed as a percentage from 0 to 100 with the higher value presenting greater inhibition.

Study contacts

Contact information is provided by the study sponsor or research team.

Kristin Cadenhead

CONTACT

[email protected]

619-543-6445

Sponsors and collaborators

Lead sponsor

University of California, San Diego

Other

Collaborators

  • Center for Medicinal Cannabis Research

Registry information

Official study title

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

Important dates

Study start
2022
Primary completion
2026
Study completion
2026
First posted
Jun 2, 2020
Registry last updated
Jan 8, 2026

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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