STIM'ZO : Examining tDCS as an add-on Treatment for Persistent Symptoms in Schizophrenia

STIM'ZO : Examining tDCS as an add-on Treatment for Persistent Symptoms in Schizophrenia (SCH)

This project aims to provide the proof of concept for transcranial direct-current stimulation (tDCS) in the treatment of resistant/persistent Schizophrenia symptoms. The purpose is to investigate the effect of tDCS on symptoms in schizophrenic patients demonstrating a partial response to a first frequently prescribed antipsychotic medication. An early optimization of the therapeutic strategy must constitute an important factor for prognosis. Hypothesize is that tDCS should alleviate symptoms in patients depending on the clinical characteristics. In this study, stimulation is an add-on treatment to antipsychotic medication, and will be used in a broad variety of patients, i.e. in patients with varied durations of illness, various symptoms profiles, and various levels of treatment response. This in turn will allow the determination of the extent to which results can be generalized to varied patient populations, as well as the extent to which various therapeutic targets (e.g. different symptom dimensions, cognitive performance and brain connectivity) may be improved with tDCS. Despite interesting preliminary results, our team is unable to describe optimal non-invasive brain stimulation (NIBS) response markers.

This study is a randomized, double blind, controlled, French multicenter study (11 centers). The investigators plan to include 144 patients with persistent symptoms in schizophrenia. Seventy two subjects will receive active tDCS and 72 subjects will receive sham tDCS (placebo). Hypothesize is a lasting effect of active tDCS on the schizophrenic symptoms as measured by the number of responders, defined as a decrease of at least 25% of symptoms as measured by a standardized clinical scale score (PANSS) between baseline and after the 10-session tDCS regimen.

Furthermore, the participants believe that an in depth understanding of the cortical effects of tDCS could constitute an important step towards improving the technique and developing treatment response markers. An analysis of the effects on cortical activity and plasticity markers could be an interesting approach.

Inclusion Criteria:

1. Diagnosis of schizophrenia according to DSM 5.0 (Diagnostic and Statistical Manuel 5.0) criteria
2. Presence of symptoms despite the optimization of the antipsychotic dosage (based on prescriber's judgment) for at least 6 weeks, i.e. a dosage increase cannot be considered due to tolerability issues and/or is judged unlikely to bring sufficient clinical improvement. This will be operationalized by a minimum Negative PANSS score of 20 and at least one item scoring > 4; OR a minimum Positive PANSS score of 20 with at least one item scoring > 4 (e.g. delusion or hallucination), indicating persistent negative symptoms and/or persistent positive symptoms,
3. Patient under curatorship/guardianship or not
4. Age between 18 and 65 years old.
5. Covered by, or having the right to Social Security
6. Patient who understands the French language
7. Informed consent signed

Exclusion Criteria:

1. Other neuropsychiatric disorders (psychiatric history will be assessed using the MINI 6.0 (Mini International Neuropsychiatric Interview 6.0)) including bipolar disorders and mood depression disorders - (NB: Patients with substance related and addictive disorders will not be excluded from the study, but these data will be carefully recorded).
2. Contraindications for tDCS (neurologic stimulator, pacemaker, cardiac defibrillator, cardiac prosthesis, vascular prosthesis, intracranial clips or clamps, cerebrospinal fluid derivation, metallic splinters in the eyes),
3. Increase in total composite PANSS score of at least 20% between screening and enrollment visits
4. Women who are pregnant
5. Patients whose clinical condition requires in patient procedure under constraint