Examining tDCS Effect on Cannabis Use Disorder in Patients With Schizophrenia

Not Applicable

Recruiting

• Conditions: Schizophrenia; Cannabis-Induced Disorder
• Interventions: Device: Transcranial direct current stimulation (tDCS) non active; Device: Transcranial direct current stimulation (tDCS) active

• Registration Number: NCT04871048
• Lead Sponsor: Centre Hospitalier Universitaire de Saint Etienne

Brief Summary

Cannabis use disorder is a frequent comorbidity of schizophrenia, associated with increased symptoms and less adherence to therapy. Validated care has limited effectiveness in this population and development of new management strategies seems necessary. Transcranial direct current stimulation (tDCS) has shown beneficial effects in both schizophrenia, substance use disorder and, in a less extent, in nicotine addiction in schizophrenic subjects. It is interesting to test if that 10 sessions of anodal stimulation of the right dorsolateral prefrontal cortex (DLPFC) and cathodal stimulation of the medial prefrontal cortex (MPFC) (by increasing control and modulating reward system), will reduce, in 110 schizophrenic subjects, cannabis consumption, and secondly craving, addiction severity, schizophrenic symptoms and improve global functioning. It is possible that these clinical effects will be associated with changes in certain cognitive functions and cerebral connectivity.

Detailed Description

Stimulation will be performed using a Neurocan DC-Stimulator Plus with two 7×5 cm sponge electrodes soaked in a saline solution. Electrodes will be placed in accordance with the international 10-20 electrode placement system: the anode over F4 (right DLPFC), the cathode over Fp1 (MPFC). The stimulation level will be set at 2 mA for 20 minutes during stimulation sessions twice a day (separated by at least 3 hours) for 5 consecutive weekdays.

The control group will receive the sham stimulation following the same regimen, using the sham procedure which has been developed by the manufacturer of the tDCS material, allowing sensations to be felt in the scalp which are the equivalent to those of the active stimulation. The same device will be used for both the sham and the active procedures.

Study Timeline

• Study First Submitted: 2021-04-23
• Study First Submitted QC: 2021-04-28
• Study First Posted: 2021-05-04
• Study Start: 2023-02-15
• Status Verified: 2025-03
• Last Update Submitted: 2025-03-17
• Last Update Posted: 2025-03-18
• Primary Completion: 2025-09-01
• Study Completion: 2026-03-01

Recruitment & Eligibility

• Status: RECRUITING
• Sex: All
• Target Recruitment: 110

Inclusion Criteria

• Schizophrenia diagnostic according to DSM (Diagnostic and Statistical Manual of mental disorder) 5 criteria, without change in psychotropic treatment since at least 4 weeks
• Moderate to severe cannabis use disorder according to DSM 5 criteria and active consumption during the last 7 days
• Subjects motivated to reduce or quit their cannabis consumption
• Patients with ambulatory compulsory care may be included

Exclusion Criteria

• Other substance use disorder, excluding nicotine, according to DSM 5 criteria
• Other current psychiatric disorder according to DSM 5 criteria, excluding personality disorder
• Inpatient hospitalization
• History of head injury, neurological disorder with cerebral consequence or severe unstable somatic disorder
• Pregnancy or no contraception
• Contraindications for tDCS and/or MRI (implanted material, uncontrolled epilepsy, intracranial hypertension)

Study & Design

• Study Type: INTERVENTIONAL
• Study Design: PARALLEL

Arm && Interventions

Group	Intervention	Description
sham tDCS stimulation	Transcranial direct current stimulation (tDCS) non active	Transcranial direct current stimulation tDCS-The control group will receive the sham stimulation following the same regimen, using the sham procedure .
active tDCS stimulation	Transcranial direct current stimulation (tDCS) active	Transcranial direct current stimulation tDCS-Stimulation will be performed using a Neurocan DC-Stimulator Plus

Primary Outcome Measures

Name	Time	Method
cannabis use	6 months	Percentage change in cannabis use before and after tDCS treatment

Secondary Outcome Measures

Name	Time	Method
Hospitalizations	6 months	Number of hospitalization(s) during the 6 months after tDCS sessions
cannabis use	3 months	Percentage change in cannabis use before and after 3 months tDCS treatment
Change in craving scores	3 months and 6 months	Marijuana Craving Questionnaire score (minimum =12, maximum = 84). The higher the score, the greater the craving.
Study of structural cerebral connectivity	3 months	Cerebral MRI (only for a subgroup of patients) : Diffusion of water at the white matter level for the evaluation of structural brain connectivity in DTI mode (diffusion tensor) on
Study of structural and functional cerebral connectivity	3 months	Cerebral MRI (only for a subgroup of patients) : Functional connectivity index evaluated by resting state default mode network (MRI) for the evaluation of functional brain connectivity

Trial Locations

Locations (8)

CHU de Clermont-Ferrand Service de Psychiatrie; 🇫🇷 Clermont-Ferrand, France

Service Hospitalo-Universitaire d'Addictologie CHU de Dijon; 🇫🇷 Dijon, France

Centre Hospitalier Alpes Isère; 🇫🇷 Saint-Égrève, France

CHU Pôle de Psychiatrie Neurologie et Rééducation; 🇫🇷 La Tronche, France

CH Le Vinatier Service universitaire d'addictologie de Lyon; 🇫🇷 Bron, France

Centre Hospitalier Universitaire Service d'Addictologie et Pathologies Duelles; 🇫🇷 Clermont-Ferrand, France

CH Saint-Cyr-au-Mont-d'Or service de psychiatrie; 🇫🇷 Saint-Cyr-au-Mont-d'Or, France

CHU de Saint-Etienne; 🇫🇷 Saint-Priest-en-Jarez, France