Nearly 10% of people hospitalized in psychiatry have a catatonic syndrome. The treatment of this syndrome is based on lorazepam and electro-convulsive therapy (ECT) in drug-resistant forms. ECT is the reference therapy, very effective in catatonia, but remain difficult to access due to the technical platform required for their realization, leading to delays in the implementation of the treatment responsible for an increase in the morbidity and mortality of catatonia. In this context, a new therapeutic tool available in the treatment of drug-resistant catatonia would improve the prognosis of catatonia. Transcranial direct current stimulation (tDCS) is an alternative, non-invasive brain stimulation technique that does not require anesthesia, and inexpensive and has been shown to be effective in depression and schizophrenia. A series of clinical cases suggests its potential efficacy in catatonia. Our objective is to evaluate the efficacy of tDCS in catatonia in a clinical trial.

Catatonia is a pathology combining affective, motor, behavioural and neuro-vegetative symptoms. Nearly 10% of people hospitalized in psychiatry have a catatonic syndrome. However, it is a severe disorder with a potentially lethal course.

For the treatment of catatonia, lorazepam is effective in most cases, with the percentage of responding patients varying between 70 and 80 per cent, according to the literature. Catatonic episodes resistant to lorazepam are usually associated with chronic catatonia as part of a neurodevelopmental disorder. Genetic abnormalities are often found in these forms of catatonia.

Electroconvulsive therapy (ECT) should be considered for any catatonic episode that is resistant to lorazepam. It is also indicated when a rapid effect must be obtained in life-threatening situations (e.g. malignant catatonia) or when the underlying pathology requires this treatment. Its efficacy is considered excellent, with response rates ranging from 59% to 100%, including when patients have not responded to lorazepam.

There are several limitations to ECT treatment for catatonia:

• There are many centres, particularly in France, where ECT is inaccessible. Delays in access to ECT are particularly acute in rural areas.
• ECT requires a pre-therapeutic assessment, delaying treatment by several days. However, catatonic syndrome is an emergency requiring immediate treatment. Delaying treatment exposes the patient to the risk of aggravation, i.e. malignant catatonia, with a life-threatening outcome.
• ECT treatment is sometimes contraindicated because of contraindications to anaesthesia.

Among neuromodulation techniques, the promising alternative approaches are transcranial magnetic stimulation (rTMS) and transcranial direct current stimulation (tDCS).

Transcranial direct current stimulation (tDCS) is a non-invasive electrical brain stimulation that does not require anaesthesia. The tDCS is based on applying a low direct electrical current (typically less than 20 volts) via two electrodes placed on the scalp. The electric current is applied to the anode (positive electrode) and then flows to the cathode (negative electrode). The electrodes, surrounded by sponges soaked in a saline solution, are positioned at the level of the scalp according to the international 10-20 placement system or, more rarely, according to the MRI-guided neuronavigation system. The device is easily transportable and does not require a specific technical platform.

The present study, randomized versus placebo, aims to test the efficacy of tDCS stimulation on catatonic-resistant syndrome.

Inclusion Criteria:

• Men or women over 18 years old
• Under the care of the GHU PARIS Psychiatry and Neurosciences or EPS Ville Evrard.
• Suffering from an episode of catatonia according to the DSM-5 CRITERIA
• Persistence of catatonia criteria according to DSM-5 after 24 hours of lorazepam treatment or contraindication to lorazepam or poor tolerance to lorazepam
• Patient (or guardian) having given informed and written consent
• Beneficiary of a social security plan

Exclusion Criteria:

• Malignant catatonia
• Pregnant or breastfeeding women
• Patients with contraindications to tCDS, namely patients with a defibrillator or a pacemaker, brain stimulator, presence of intracranial metals, uncovered craniectomy or after trepanning.