INTERVENTIONALACTIVE NOT RECRUITINGNCT02926859

Enhancing Recovery in Early Schizophrenia - a Multi-center, Two-arm, Double-blind, Randomized Phase II Trial Investigating Cannabidiol vs. Placebo as an add-on to an Individualized Antipsychotic Treatment

Current antipsychotic treatments of schizophrenia 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 and has no psychotomimetic or addictive properties. In a controlled clinical trial of cannabidiol versus amisulpride in acute paranoid schizophrenia we showed a statistically significant clinical improvement in all symptoms clusters of schizophrenia compared to baseline with either treatment. Cannabidiol displayed a significantly superior side-effect profile in particular regarding prolactin elevation, extrapyramidal symptoms and weight gain. The favorable side-effect profile and potentially novel mechanism of action identify this molecule as a potential antipsychotic. However, long-term safety and efficacy data is still lacking. This study is to evaluate the efficacy and safety of the novel compound cannabidiol in the maintenance treatment of schizophrenia in comparison to placebo as an add-on to an established treatment with either amisulpride, aripiprazole, olanzapine, quetiapine or risperidone, in a 12-months, double-blind, parallel-group, randomized, placebo-controlled clinical trial. Thereby, relevant data on cannabidiol's antipsychotic potential will be gained.

Locally preserved from ClinicalTrials.govOpen ClinicalTrials.govlast source update 2026-02-03

What this record can show

Protocol only - no registry results posted

This locally preserved record separates the registered protocol from source-reported registry results. Neither is a treatment recommendation.

Registry facts

Study at a glance

Phase: PHASE2
Enrollment: 180 (ESTIMATED)
Start date: 2017-04-08
Sponsor: Central Institute of Mental Health, Mannheim
Design: RANDOMIZED · PARALLEL · TREATMENT
Locations: 6
Results record: Not present in registry snapshot

Linked local records

Related local records

Local links use governed condition terms or exact source-reported intervention names. They are navigation candidates, not efficacy claims.

Conditions

No published condition report matched.

Cannabinoids and active compounds

cannabidiol

Medicines

No exact medicine-name link was found.

Interventions

What was registered

DRUG

Cannabidiol as add-on

Cannabidiol capsules 2x200 mg twice a day as add-on to individualized pharmacological treatment with either amisulpride, aripiprazole, olanzapine, quetiapine or risperidone over 26 weeks

DRUG

Placebo as add-on

Placebo capsules 2x200 mg twice a day as add-on to individualized pharmacological treatment with either amisulpride, aripiprazole, olanzapine, quetiapine or risperidone over 26 weeks

Eligibility

Population and criteria

Sex: ALL
Minimum age: 18 Years
Maximum age: 65 Years
Healthy volunteers: Not accepted

Protocol only - no registry results posted

Study at a glance

Related local records

Conditions

Cannabinoids and active compounds

Medicines

What was registered

Cannabidiol as add-on

Placebo as add-on

Population and criteria

Inclusion criteria

Exclusion criteria

primary measures

All-cause discontinuation

secondary measures

Improvement in Psychopathology assessed by PANSS

Improvement in Psychopathology assessed by CGI

Improvement in Psychopathology assessed by BSI-53

Improvement in Psychopathology assessed by FROGS

Changes from baseline in Depression Scale

Improvement in social and occupational functioning assessed by GAF

Improvement in social and occupational functioning assessed by PSP

Improvement in social and occupational functioning assessed by EMA

Improvement in Quality of life assessed by WHOQUOL-Bref

Improvement in Quality of life assessed by LQLP

Changes from baseline in Neurocognition assessed by B-CATS

Changes from baseline in Neurocognition assessed by BACS

Changes from baseline in Neurocognition assessed by UPSA-B

Changes from baseline in Neurocognition assessed by MASC

Changes from baseline in Neurocognition assessed by PFA

Treatment adherence

Changes in Cumulative dose of concomitant or rescue medication

Changes of Biomarker: alterations of endocannabinoids and lipdomic profiling

other measures

Side effects: weight gain

Side effects: Vital Signs

Side effects: UKU Side Effect rating scale

Side effects: Abnormal Involuntary Movement Scale (AIMS)

Side effects: Evaluation of extrapyramidal symptoms (EPS)

Side effects: physical and neurological examination

Standard blood tests

Columbia Suicidality Sverity Rating Scale (C-SSRS)

Locally readable linked articles