The effectiveness of Transcranial Direct- Current Stimulation (TDCS) combined with medication on negative symptoms of schizophrenic patients

Schizophrenia is one of the chronic psychiatric disorders that positive and negative symptoms, particularly negative ones, causes reducing performance in personal, social, and family performances.
The present study is aimed to investigate the effectiveness of Transcranial Direct Current Stimulation (TDCS) in combination with pharmacotherapy on negative symptoms of schizophrenia.
This is a single-subject method with multiple baseline and follow-up design. Four patients with schizophrenia diagnosis by psychiatrist were selected via purposive and convenience sampling method. The negative symptoms were measured using the Andresen’s Negative Symptom Scale (1982). Patients entered the intervention phase step by step and received stimulation with intensity of 2 mA in their cortical region of the Left Dorso – Lateral Prefrontal Cortex in ten sessions. At the end of the second, fourth, sixth, eighth, and tenth sessions, they were interviewed and their scores were recorded. Two weeks follow up was done. To analyze the data trend and stability index was used.
The results indicated that the Trans cranial Direct Current Stimulation in combination with pharmacotherapy has the highest effectiveness on alogia (poverty of speech) and Attention-Deficit in all four subjects. But its effects on the affective flattening or blunting and avoliton- apathy, anhedonia- asociality depending on the patient's age, the duration of suffering from the disease, and medicinal diet of patients are different.
Based on results it can be said that Trans cranial Direct Current Stimulation in combination with pharmacotherapy can be effective in reducing negative symptoms of schizophrenic patients.