Evaluation of the Antipsychotic Efficacy of Cannabidiol in Acute Schizophrenic Psychosis (CBD-CT1)
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ClinicalTrials.gov Identifier: NCT00628290 |
Recruitment Status :
Completed
First Posted : March 5, 2008
Last Update Posted : March 18, 2008
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A controlled, randomized study on the treatment of schizophrenic psychosis with cannabidiol, a phytocannabinoid is performed. This approach is based upon recent findings indicating that the human endogenous cannabinoid system is significantly involved in the pathogenesis of schizophrenia. Our group has shown, for example, that Δ9-tetrahydrocannabinol (Δ9-THC) is able to provoke schizophrenia-like psychotic symptoms in healthy volunteers. This, as well as the capability of Δ9-THC to exacerbate productive psychotic symptoms in schizophrenic patients, has recently been confirmed by others. Furthermore, we found that the en-dogenous brain constituent anandamide, an endogenous Δ9-THC agonist, is significantly elevated in the CSF of schizophrenic patients. Cannabinergic substances such as anandamide may enhance dopaminergic neurotrans-mission by increasing dopamine turnover. They may also influence the onset or course of schizophrenia by as yet unidentified mechanisms We seek to investigate the efficacy of cannabidiol in the treatment of schizophrenic and schizophreniform psy-choses, because there is evidence that CB1 antagonists such as SR141716 and cannabidiol have antipsychotic effects comparable to those of classic neuroleptic drugs. Furthermore, cannabidiol is well tolerated showing few side effects in humans. Cannabidiol may serve as an antipsychotic medication that is not primarily based upon an antidopaminergic but upon different mechanisms, especially anticannabinergic ones. It may therefore be an effec-tive medication in at least a subgroup of schizophrenic and schizophreniform patients and may be expected to show additional anxiolytic effects and only minor side effects.
The control condition in this parallel design will be an established neuroleptic treatment with amisulpride that is primarely an antidopaminergic drug. Thus, we will study not only the antipsychotic efficacy of cannabidiol, but we will also compare the effects of both treatment strategies on side effects and neuropsychological functioning.
Condition or disease | Intervention/treatment | Phase |
---|---|---|
Schizophrenia | Drug: Cannabidiol Drug: Amisulpride | Phase 2 |
Study Type : | Interventional (Clinical Trial) |
Estimated Enrollment : | 42 participants |
Allocation: | Randomized |
Intervention Model: | Parallel Assignment |
Masking: | Quadruple (Participant, Care Provider, Investigator, Outcomes Assessor) |
Primary Purpose: | Treatment |
Official Title: | Evaluation of the Antipsychotic Efficacy of the Phytocannabinoid Cannabidiol in Treating Acute Schizophrenic Psychosis. A Double-Blind, Controlled Clinical Trial |
Study Start Date : | October 2002 |
Actual Primary Completion Date : | November 2004 |
Actual Study Completion Date : | March 2008 |

Arm | Intervention/treatment |
---|---|
Experimental: 1 |
Drug: Cannabidiol
Capsules, 3 times daily, 200 mg, 4 weeks |
Active Comparator: 2 |
Drug: Amisulpride
Capsules, 3 times daily, 200 mg, 4 weeks |
- Change in BPRS total value. [ Time Frame: 4 weeks ]
- Change in PANSS scores. [ Time Frame: 4 weeks ]
- EPS [ Time Frame: 4 weeks ]
- Weight gain [ Time Frame: 4 weeks ]
- Prolactin levels in serum [ Time Frame: 4 weeks ]

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Ages Eligible for Study: | 18 Years to 65 Years (Adult, Older Adult) |
Sexes Eligible for Study: | All |
Accepts Healthy Volunteers: | No |
Inclusion Criteria:
- Clinical diagnosis of schizophrenia or schizophreniform psychosis according to DSM-IV.
- BPRS score >36 and BPRS psychosis cluster > 12.
- Ability to provide written informed consent.
- Participants are required an adequate contraception.
Exclusion Criteria:
- Any severe neurological or somatic disorder.
- Other psychiatric disorders including addictive disorders.
- Positive urine drug screening for any compound except benzodiazepines.
- No pregnancy or breast feeding.

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.
Please refer to this study by its ClinicalTrials.gov identifier (NCT number): NCT00628290
Germany | |
University of Cologne, Dept. of Psychiatry and Psychotherapy | |
Cologne, NRW, Germany, 50924 |
Principal Investigator: | Franz-Markus Leweke, MD | University of Cologne, Dept. of Psychiatry and Psychotherapy |
Responsible Party: | Dr. F. Markus Leweke, University of Cologne |
ClinicalTrials.gov Identifier: | NCT00628290 |
Other Study ID Numbers: |
CBD-CT1 SMRI Grant ID: 00-093 |
First Posted: | March 5, 2008 Key Record Dates |
Last Update Posted: | March 18, 2008 |
Last Verified: | January 2008 |
Epidiolex Schizophrenia Schizophrenia Spectrum and Other Psychotic Disorders Mental Disorders Amisulpride Anticonvulsants Antipsychotic Agents Tranquilizing Agents Central Nervous System Depressants |
Physiological Effects of Drugs Psychotropic Drugs Dopamine Antagonists Dopamine Agents Neurotransmitter Agents Molecular Mechanisms of Pharmacological Action Antidepressive Agents, Second-Generation Antidepressive Agents |