Efficacy of transcranial direct and alternating stimulation of the prefrontal cortex on cognitive functions and symptoms in schizophrenic patients: A double-blind randomized clinical trial with the control group

Evaluation of direct and alternating electrical stimulation of brain on cognitive functions and symptoms in people with schizophrenia

A double-blind, randomized clinical trial with a control group on 114 patients. Random allocation software will be used for randomization.

In the first phase, 54 eligible patients with schizophrenia will be randomly assigned into two groups of 27 and in the second phase, another 60 patients will be randomly assigned into three groups of 20. This clinical trial is double-blind and the patient and the outcome assessor are not aware of the type of intervention. The study site will be Fatemi Hospital in Ardabil.

Inclusion: Diagnosis of schizophrenia based on DSM V, Being 18-50 years old, Required written informed consent signed by patients' guardian, Exclusion: Pregnancy, The existence of metal implants in the body, History of neurological diseases

In the first phase, patients will be randomly assigned into two groups. The first group will receive three conditions of tDCS (2 mA, 3 mA, and sham) and the second group will receive three conditions of tACS (8 Hz, 40 Hz, and sham) in three sessions of 20 minutes with an interval of three days. the anodic electrode is placed over the F3 and the cathode electrode is placed over the right shoulder. In the second phase, another 60 patients will be randomly assigned into three groups with active tDCS, active tACS, and sham, and by the results of the first phase, the stimulation will be performed for 10 consecutive days in two sessions of 20 minutes per day, with an interval of 20 minutes. Sham stimulation is as same as active stimulation, except that there will be no current and the device will turn off after one minute.

cognitive functions؛ Symptoms of schizophrenia

In this study, we will use the Restricted Randomization method of block randomization and in each phase, we will have 6 blocks. Generation of random sequences via the blocking method will be done by Random Allocation software. To conceal, we use Allocation Concealment, which refers to the method used to perform a random sequence on study participants, so that the assigned group is not identified before the individual is assigned. Also, non-transparent envelopes sealed with random sequences will be used, that in this method each random sequence is recorded on a card and the cards are placed in the envelope in order. In order to maintain a random sequence, the envelopes are numbered in the same way on the outer surface. Finally, the lids of the envelopes are glued and placed inside a box, respectively. At the beginning of the registration, according to the order of entry of the eligible participants, one of the envelopes will be opened in order and the assigned group of the participant will be revealed.

The executive specialist of electrical brain stimulation will be aware of the research topic and will perform therapeutic interventions. He codes the patients and refers them to a psychologist to check the patient's mental state and record the relevant criteria based on the same code. The patients will be tested in the same condition in the Neurotherapy room and the electrodes of the device will be connected to them, but they will not be aware of the type of stimulation. The experimenter who assesses outcome measures will be independent from the one who applied intervention and will be blind to stimulation condition. This method of double-blinding is based on previous works in the field of transcranial electrical stimulation (Gandinga et al., 2006). Accordingly, this study will be a double-blind study.

Due to the confidentiality of the participant's personal characteristics

All collected data for the primary outcome measures only after anonymizing

Starting 12 months after publication

Researchers working in academic and scientific institutions

To raise the level of knowledge about the treatment of schizophrenia

Raw data and documents generated for this study are available from the corresponding authors and institution on reasonable request.

A formal request from person/institutions should be sent to the corresponding authers and corresponding institutions via email (for international users) and mail (for national users).