Enhancing recovery in early schizophrenia: A study comparing cannabidiol and placebo as add-on to standard antipsychotic treatment.

Phase 2

Recruiting

Conditions: Remitted early phase schizophrenia

Registration Number: 2024-517198-26-00

Lead Sponsor: Zentralinstitut Fuer Seelische Gesundheit

Brief Summary: To evaluate the efficacy of cannabidiol compared to placebo as

an add-on to state-of-the-art antipsychotic maintenance

treatment of schizophrenia.

Detailed Description: Not available

Recruitment & Eligibility

Status: Ongoing, recruiting

Sex: Not specified

Target Recruitment: 180

Inclusion Criteria

Informed consent given by the subject

DSM-IV-TR diagnosis of schizophrenic psychosis (295.10, 295.20, 295.30, 295.90)

Patients must receive a stable oral dose of amisulpride (up to 1200 mg/day), aripiprazole (up to 30 mg/day), olanzapine (up to 20 mg/day), paliperidone (up to 12 mg/day), quetiapine (up to 750 mg/day), or risperidone (up to 10 mg/day) (TAU: treatment as usual) at least two weeks prior to inclusion in the study to ensure that the maximal effect of the previous medication has been received

Age 18 to 65 years, male or female

Initial PANSS total 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 (Subjects with a BMI>40 and no further medical conditions that could indicate a metabolic syn-drome may enter the study based on the approval of the coordinating investigator)

Fluent in German or English

Exclusion Criteria

Lack of accountability (assessed by an independent psychiatrist)

Treatment-resistant schizophrenia (TRS) defined as the persistence of symptoms despite ≥2 trials of antipsychotic medications of adequate dose and duration with documented adherence

Use of long-acting antipsychotics <3 months of end of proposed duration of action of respective dosage form prior to randomization

Positive urine drug-screening for illicit drugs at screening (except cannabinoids and benzodiazepines)

Serious suicidal risk at screening visit (Subject to investigator’s judgment)

Other relevant interferences of axis 1 (e.g., serious depression) according to diagnostic evaluation (M.I.N.I) including residual forms of schizophrenia

Other relevant neurological or other medical disorders

Pregnancy, determined through a β-HCG pregnancy test, or nursing (i.e., lactation at screening visit)

Study & Design

Study Type: INTERVENTIONAL

Study Design: Not specified

Primary Outcome Measures

Name	Time	Method
All-cause discontinuation within 12 months following randomization as defined by any of the following conditions: 1) relevant worsening of symptoms; 2) not taking medication as prescribed for more than 14 consecutive days; 3) not keeping appointments as scheduled for more than six weeks; 4) not being traceable despite extensive efforts; withdrawal of informed consent; 6) termination of treatment on investigators request due to clinical reasons		All-cause discontinuation within 12 months following randomization as defined by any of the following conditions: 1) relevant worsening of symptoms; 2) not taking medication as prescribed for more than 14 consecutive days; 3) not keeping appointments as scheduled for more than six weeks; 4) not being traceable despite extensive efforts; withdrawal of informed consent; 6) termination of treatment on investigators request due to clinical reasons

Secondary Outcome Measures

Name	Time	Method
Improvement in Psychopathology from baseline (PANSS, CGI, BSI-53, FROGS), social and occupational functioning (GAF, PSP) and quality of life (WHOQUOL-Bref, LQLP).		Improvement in Psychopathology from baseline (PANSS, CGI, BSI-53, FROGS), social and occupational functioning (GAF, PSP) and quality of life (WHOQUOL-Bref, LQLP).
Changes from baseline in the Calgary Depression Scale for Schizo-phrenia (CDSS).		Changes from baseline in the Calgary Depression Scale for Schizo-phrenia (CDSS).
Changes from baseline in Neurocognition.		Changes from baseline in Neurocognition.
Drug Attitude Inventory (DAI) and self-reported treatment adherence.		Drug Attitude Inventory (DAI) and self-reported treatment adherence.
Changes of cumulative dose of concomitant or rescue medication.		Changes of cumulative dose of concomitant or rescue medication.
Changes of biomarkers: alteration in endogenous cannabinoids and lipidomic profiling.		Changes of biomarkers: alteration in endogenous cannabinoids and lipidomic profiling.
Changes from baseline in the UKU Side Effect Rating Scale, Abnormal Involuntary Movement Scale (AIMS) and evaluation of ex-trapyramidal symptoms (EPS).		Changes from baseline in the UKU Side Effect Rating Scale, Abnormal Involuntary Movement Scale (AIMS) and evaluation of ex-trapyramidal symptoms (EPS).
Columbia Suicidality Severity Rating Scale (C-SSRS).		Columbia Suicidality Severity Rating Scale (C-SSRS).
Other safety and tolerability assessments including (S)AEs, physical examination, abdominal girth, body mass index (BMI), vital signs (including heart rate and systolic and diastolic blood pressure in both supine and standing positions), ECG, assessments for neurological functioning and detailed laboratory assessments.		Other safety and tolerability assessments including (S)AEs, physical examination, abdominal girth, body mass index (BMI), vital signs (including heart rate and systolic and diastolic blood pressure in both supine and standing positions), ECG, assessments for neurological functioning and detailed laboratory assessments.

Trial Locations

Locations (1): Zentralinstitut Fuer Seelische Gesundheit
🇩🇪
Mannheim, Germany
Zentralinstitut Fuer Seelische Gesundheit
🇩🇪Mannheim, Germany
Franz-Markus Leweke
Site contact
+4962117032761
markus.leweke@zi-mannheim.de