The use of transcranial direct current stimulation (tDCS) was found to be safe and effective for patients with schizophrenia and predominant negative symptoms, according to study results published in JAMA Psychiatry.
Researchers in São Paolo, Brazil conducted a double-blind placebo-controlled randomized study of 100 patients aged 18 to 55 years with schizophrenia and prominent negative symptoms in 2 outpatient clinics. To be enrolled in the study, patients had to have stable positive and negative symptoms as well as a proper antipsychotic treatment regimen for 4 weeks or more preceding trial onset.
Patients were randomly assigned to receive either 20 minutes of tDCS twice daily for a total of 5 days or a sham intervention. The tDCS montage placed the anode over the left prefrontal cortex and the cathode over the left temporoparietal junction. The primary outcome was the change in negative symptom score as measured by the Positive and Negative Syndrome Scale (PANSS) from start of tDCS treatment to 6 weeks. Secondary outcomes included clinical response of 20% improvement, changes in positive symptoms, Calgary Depression Scale for Schizophrenia score, and sociodemographic factors, among others.
The 100 patients (20 women; mean age, 35.3±9.3 years) included in the study were evenly split between the intervention and control groups.
The researchers found that patients treated with tDCS had significantly better improvement in PANSS score compared with patients in the sham intervention (score difference, 2.65; 95% CI, 1.51-3.79; number needed to treat, 3.18; 95% CI, 2.12-6.99; P <.001).
Moreover, response to treatment for negative symptoms was greater for patients in the tDCS arm compared with the sham arm at weeks 6 and 12 (both P <.001).
In regard to safety, the procedure was well-tolerated and adverse events were largely similar in both groups. No serious adverse events were reported in the study. In post-hoc analyses, there were significant improvements in all PANSS negative symptom subscales, except passive/apathetic withdrawal and stereotyped thinking.
Study limitations included relatively low absolute active and sham changes. Overall, the study successfully found significant differences between active and sham groups in terms of the primary outcome and validated prior findings.
“Our findings encourage the use and optimization of this technique in patients with psy- chotic disorders,” the researchers concluded.
Disclosures: Some authors have declared affiliations with the pharmaceutical industry. Please refer to the original study for a full list of disclosures.
Valiengo LDCL, Goerigk S, Gordon PC, et al. Efficacy and safety of transcranial direct current stimulation for treating negative symptoms in schizophrenia: a randomized clinical trial [published online October 16, 2019]. JAMA Psychiatry. doi:10.1001/jamapsychiatry.2019.3199