Transcranial Direct Current Stimulation Plus Zoloft Has Better Antidepressant Effects Than Either Treatment Alone
Transcranial direct current stimulation (tDCS), in which a barely perceptible level of electrical current is applied directly from one side of a patient’s scalp to the other, is a promising treatment for patients with tought-to-treat depression. A 2013 study by Brunoni et al. in JAMA Psychiatry examined whether combined treatment using tDCS and the selective-serotonin reuptake inhibitor (SSRI) antidepressant sertraline (Zoloft) would be a safe and effective treatment for unipolar depression. The combination was better than either treatment alone and better than placebo.
The six-week study used what is called a 2×2 factorial design, in which 120 patients with unipolar depression received either 50 mg/day of sertraline or placebo and also received either real tDCS or a sham procedure. The tDCS was administered in twelve 30-minute sessions, one per day Monday through Friday during the first two weeks, followed by one every other week. TDCS consists of an anodal (positive) and cathodal (negative) current placed at particular positions on the head. This study used 2 microamps of anodal left/cathodal right prefrontal stimulation for the tDCS treatment.
While the combination of sertraline and tDCS was significantly better than all three other treatment options (sertraline plus sham procedure, placebo plus tDCS, and placebo plus sham procedure), sertraline by itself and tDCS by itself resulted in similar efficacies. However, TDCS by itself was also significantly better than placebo, while sertraline by itself was not.
Side effects among the different treatment options were similar, except those who received tDCS had more scalp redness. There were seven instances of patients developing mania or hypomania during the study, five of which occurred in the combined tDCS and sertraline treatment group, higher than the 1–2% rate that would be expected in a study of unipolar depression.