Schizophrenia is a heterogeneous mental disorder that affects one percent of the world's population. Current antipsychotics are only partially effective, and their use is often associated with serious side effects. Cannabidiol is a natural counterpart of the psychoactive component of marijuana, delta-9-tetrahydrocannabinol. While cannabidiol has no psychotomimetic or addictive properties, it indirectly affects endogenous cannabinoid signalling by impairing the degradation of the endocannabinoid anandamide. In a controlled clinical trial of cannabidiol versus amisulpride (an established antipsychotic) in acute paranoid schizophrenics the investigators showed a significant clinical improvement in all symptoms of schizophrenia compared to baseline with either treatment. But cannabidiol displayed a significantly superior side-effect profile. This study is to evaluate the efficacy and safety of this novel treatment option in comparison to placebo and olanzapine, an established second generation antipsychotic in the treatment of acute schizophrenia and schizophrenia maintenance therapy, in a four-week clinical trial.
Who can participate
Age range
18 Years – 65 Years
Sex
ALL
See this in plain English?
AI-rewrites the medical criteria so a patient or caregiver can understand them. Always confirm with the trial site.
Inclusion Criteria:
* Informed consent given by the subject
* DSM-IV-TR diagnosis of schizophrenic psychosis (295.10, 295.20, 295.30, 295.90 (American Psychiatric Association)
* Patients must be within the first three years of illness, i.e. first diagnosis of schizophrenia is no older than three years.
* Age 18 to 65 years, male or female
* Minimal initial PANSS score of 75 at baseline
* Female patients of childbearing potential need to utilize a proper method of contraception.
* Body Mass Index between 18 and 40
Exclusion Criteria:
* Lack of accountability (assessed by an independent psychiatrist)
* History of treatment-resistant schizophrenia, defined as no response to at least two antipsychotics given for a minimum of 6 weeks each in an adequate dosage
* Positive urine drug-screening for illicit drugs at screening (except cannabinoids and benzodiazepines)
* Serious suicidal risk at screening visit (Subject to investigator's and independent psychiatrist's judgement: Poses a serious suicidal or homicidal risk at screening visit or has made a serious suicide attempt within the last 12 months prior to screening visit, or has exhibited homicidal behaviour at anytime during her/his lifetime)
* Known intolerance or allergy to olanzapine or cannabidiol
* Other relevant interferences of axis 1 (e.g. serious depression) according to diagnostic evaluation (MINI) including residual forms of schizophrenia
* Pregnancy, as determined through a β-HCG pregnancy test, or lactation
Questions worth asking your doctor
Bring these to your next appointment. They're a starting point for a shared conversation — not a sign you qualify or a recommendation to enrol.
1Based on my diagnosis and history, is this trial worth exploring for me — or is there a standard treatment we should try first?
2What does this trial's phase tell us about how much is already known about its safety and benefit?
3What would taking part actually involve for me — visits, tests, time, and travel?
4What are the known and possible risks or side effects I should weigh, and how would they be monitored?
5If this trial isn't the right fit, what other options or trials would you suggest I look into?
Generated to help you prepare — always confirm anything about your own eligibility and care with the study team and your doctor.
Questions for the trial coordinator
The trial coordinator is the person who runs the study day to day. These cover the practical side — logistics, costs, and what taking part would actually mean for your life. The study team confirms whether you meet the criteria; these are questions to ask, not a sign you qualify.
1What does taking part actually involve week to week — how many visits, where, and how long does each one take?
2What costs are covered by the study, and what might I have to pay for myself, including travel, parking, or time off work?
3What happens during screening, and what happens if the study team confirms I don't meet the criteria after those tests?
4Who pays for the scans, blood work, and other tests the trial requires — the study, my insurance, or me?
5How will being in the trial affect my regular care, and will my own doctor stay informed and involved?
6Can I leave the trial at any point if I change my mind, and what would happen to my care if I do?
A starting point for the conversation — always confirm anything about your own eligibility, costs, and care with the study team and your doctor.
What they're measuring
1
Change in the Positive and Negative Syndrome Scale (PANSS) total score
Timeframe: within 4 weeks
Trial details
NCT IDNCT02088060
SponsorCentral Institute of Mental Health, Mannheim