Frontotemporoparietal transcranial direct current stimulation (tDCS) is an effective and safe add-on treatment for improving negative symptoms in patients with schizophrenia, according to a study published online in JAMA Psychiatry.
“In line with our primary hypothesis, 10 tDCS sessions within 5 days (ie, twice a day) were effective in ameliorating negative symptoms in schizophrenia 6 weeks after treatment onset,” researchers wrote. “This effect presented a medium effect size, was reflected in higher response rates for negative symptoms, and persisted during the follow-up phase.”
The double-blind study, conducted at 2 outpatient clinics in Brazil, included 100 patients with schizophrenia with predominant negative symptoms. Participants were randomized to 2 daily sessions of tDCS or a sham procedure over 5 days. The primary outcome of the study was change in the Positive and Negative Syndrome Scale (PANSS) negative symptoms subscale score at week 6.
Among the 95 patients who completed the week of treatment, those who received tDCS demonstrated significantly greater improvement in PANSS score compared with participants who received sham treatment. Response rates for negative symptoms (defined as 20% or greater improvement) were 40% for the tDCS group compared with just 4% for the group that received sham treatment.
After an additional 6 weeks of follow-up, the superiority of tDCS was sustained. Furthermore, tDCS was not associated with significant adverse effects.
“Our findings encourage the use and optimization of this technique in patients with psychotic disorders,” researchers wrote.
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. JAMA Psychiatry. 2019 October 16;[Epub ahead of print].