Transcranial DC Stimulation Promising in Bipolar Depression

Megan Brooks

January 05, 2018

Transcranial direct current stimulation (tDCS) was effective, safe, and well tolerated as add-on treatment for bipolar depression in the first randomized sham-controlled double-blind study of tDCS in bipolar depression.

Compared with sham tDCS, active tDCS was associated with superior improvement in depressive symptoms and did not induce more manic/hypomanic episodes, the investigators report.

Results of the Bipolar Depression Electrical Treatment Trial (BETTER) were published online December 27 in JAMA Psychiatry.

Available pharmacologic and psychological treatments for bipolar depression are only modestly effective, and the side effects caused by psychopharmacologic treatments often lead to treatment discontinuation, lead investigator Andre R. Brunoni, MD, PhD, coordinator, Interdisciplinary Center for Applied Neuromodulation, University Hospital, University of São Paulo, Brazil, told Medscape Medical News. "Therefore, novel treatment options are needed."

He noted that tDCS has been "increasingly studied in the last years as an alternative for the treatment of psychiatric and neurological disorders, and the results for unipolar depression are promising." These findings led his group to study tDCS in bipolar depression.

Participants included 59 adults (40 women; mean age, 45.9 years) with type I or II bipolar disorder in a major depressive episode. The patients were receiving a stable pharmacologic regimen. Most patients were taking an antidepressant and a mood stabilizer. The patients' scores on the 17-item Hamilton Depression Rating Scale were greater than 17.

Patients received 12 sham or active tDCS sessions lasting 30 min. Ten consecutive sessions were applied once daily from Monday through Friday, with weekends off, followed by one session every 2 weeks until week 6 (study endpoint). The anode and cathode electrodes were inserted in saline-soaked sponges and were placed over the left and right dorsolateral prefrontal cortex. Active tDCS delivered a current of 2 mA. Fifty-six of the 59 patients completed the study.

Intention-to-treat analysis showed that active tDCS had significantly greater antidepressive effects than sham tDCS (differential effect size, −1.68; number needed to treat [NNT], 5.8; P = .01), the investigators report.

The cumulative response rate was significantly higher with active than sham tDCS (67.6% vs 30.4%; NNT, 2.69; P = .01). There was no statistically significant difference in remission rates, which were 37.4% with active tDCS and 19.1% with sham tDCS (NNT, 5.46; P = .18).

Rates of the occurrence of skin redness were higher with active than sham tDCS (54% vs 19%; P = .01). Other adverse events occurred with similar frequency in the two groups. There were nine episodes of treatment-emergent adverse events during the trial: five (19%) in the group receiving sham tDCS, and four (15%) in the active-treatment group (P = .71). "These episodes did not meet the criteria for a major depressive episode with mixed features, hypomania, or mania...and required no hospitalization, trial discontinuation, or specific treatment," the investigators report.

Dr Brunoni told Medscape Medical News the results of the BETTER trial in bipolar depression are "similar with that earlier found in unipolar depression trials, which is interesting. The good profile of adverse effects with tDCS and low cost make this tool even more appealing."

He said it is important to note that the study evaluated the efficacy and safety of tDCS only in the acute phase of treatment and that the sample size was small. "We hope that the future trials might be carried out with bigger sample size and be expanded for the maintenance phase evaluation," Dr Brunoni said.

Pivotal Trials Needed

Reached for comment, Alan Manevitz, MD, clinical psychiatrist at Lenox Hill Hospital in New York City, said, "The findings are interesting and consistent with what we see with transcranial magnetic stimulation [TMS], but tDCS is still in its infancy; with tDCS, we are still in spring training, so to speak.

"We know that neuromodulation works," added Dr Manevitz, who was not involved in the study. "TMS has been approved by the FDA [US Food and Drug Administration], and Medicare and insurance policies cover it because it's been shown to work. TMS is a much more proven, accepted, almost mainstream treatment," he noted.

It's important to note that this was an "add-on" study, Dr Manevitz said. "The patients were on antidepressants and mood stabilizers for about 4 weeks before tDCS, so we don't know if the tDCS was really a ripening of the medications in general for the patient. As the authors say, this was a real-world experience, but in research, to really see if something is effective, you really need to control those variables. This speaks to the need to do much larger pivotal studies of tDCS, controlling for all the independent variables," said Dr Manevitz.

This study was supported by the Brain and Behavior Research Foundation. Dr Brunoni has received honoraria from DeltaMedical and Neurocare group. Dr Manevitz has disclosed no relevant financial relationships.

JAMA Psychiatry. Published online December 27, 2017. Abstract


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