Efficacy and Safety of Transcranial Direct Current Stimulation for Treating Negative Symptoms in Schizophrenia

Abstract

IMPORTANCE Negative symptoms represent a substantial burden in schizophrenia. Although preliminary studies have suggested that transcranial direct current stimulation (tDCS) is effective for some clusters of symptoms, the clinical benefits for negative symptoms are unclear.OBJECTIVE To determine the efficacy and safety of tDCS vs sham as an add-on treatment for patients with schizophrenia and predominant negative symptoms. DESIGN, SETTING, AND PARTICIPANTS The double-blind Schizophrenia Treatment With Electric Transcranial Stimulation (STARTS) randomized clinical trial was conducted from September 2014 to March 2018 in 2 outpatient clinics in the state of São Paulo, Brazil. Patients with schizophrenia with stable negative and positive symptoms and a minimum score of 20 points in the negative symptoms subscale of the Positive and Negative Syndrome Scale (PANSS) were included. INTERVENTIONS Ten sessions of tDCS performed twice a day for 5 days or a sham procedure. The anode and the cathode were positioned over the left prefrontal cortex and the left temporoparietal junction, respectively. MAIN OUTCOMES AND MEASURESChange in the PANSS negative symptoms subscale score at week 6 was the primary outcome. Patients were followed-up for an additional 6 weeks. RESULTSOf the 100 included patients, 20 (20.0%) were female, and the mean (SD) age was 35.3 (9.3) years. A total of 95 patients (95.0%) finished the trial. In the intention-to-treat analysis, patients receiving active tDCS showed a significantly greater improvement in PANSS score compared with those receiving the sham procedure (difference, 2.65; 95% CI, 1.51-3.79; number needed to treat, 3.18; 95% CI, 2.12-6.99; P < .001). Response rates for negative symptoms (20% improvement or greater) were also higher in the active group (20 of 50 [40%]) vs the sham group (2 of 50 [4%]) (P < .001). These effects persisted at follow-up. Transcranial direct current stimulation was well tolerated, and adverse effects did not differ between groups, except for burning sensation over the scalp in the active group (43.8%) vs the sham group (14.3%) (P = .003).CONCLUSIONS AND RELEVANCE Transcranial direct current stimulation was effective and safe in ameliorating negative symptoms in patients with schizophrenia.

Moving to accelerated protocols of tDCS in schizophrenia: A case report

“…The present case provides evidence for the feasibility, tolerability and safety of accelerated tDCS in a patient with schizophrenia. The observed reduction in total PANSS scores as well as negative and general symptom subscores seems comparable to that reported in previous clinical trials [1,2]. However, the effect on hallucinations was mild and restricted to the visual modality, whereas the patient's complaints mainly concerned auditory and olfactory hallucinations.…”

“…In recent years, transcranial direct current stimulation (tDCS) has been increasingly used to reduce symptoms in patients with schizophrenia with good outcomes, particularly for auditory hallucinations [1] and negative symptoms [2]. tDCS protocols for schizophrenia typically include ten 20-min sessions of tDCS at 2 mA applied with a frontotemporal montage, i.e., with the anode over the left prefrontal cortex and the cathode over the left temporoparietal junction.…”

Evidence-Based Guidelines and Secondary Meta-Analysis for the Use of Transcranial Direct Current Stimulation in Neurological and Psychiatric Disorders

“…Therefore, while there are clear benefits to tDCS in auditory hallucinations, effects on positive and negative symptoms are harder to determine. However, we did not include a Class I RCT (n = 100) by Valiengo and colleagues ( Valiengo et al, 2019 ) that was published after our search date limits; this study showed significant and clinically relative benefits of anodal left prefrontal and cathodal left temporoparietal tDCS to negative symptoms, which would change our classification to probably effective (Level B) for negative symptoms in schizophrenia.…”

Nichtinvasive Hirnstimulationsverfahren in der Psychiatrie

“…Neben der hf-rTMS und der lf-rTMS hat zuletzt die Theta-burst-Stimulation (TBS) als spezifisch strukturierte Form der rTMS erhebliche Aufmerksamkeit erlangt. [27]. Sie führten 10 tDCS-Sitzungen innerhalb von 5 Tagen durch.…”