H1-Coil TMS Treatment Improves Cognitive Effect in Bipolar Depression

depressed woman
depressed woman
Investigators examined cognitive effects of deep transcranial magnetic stimulations in patients with treatment-resistant depression.

A study published in the Journal of Affective Disorders demonstrated the cognitive safety of H1-coil transcranial magnetic stimulation (TMS) treatment for individuals with bipolar depression.

The exploratory study sought to evaluate the effects of H1-coil TMS treatment on 6 cognitive domains (attention and processing speed, inhibitory control, working memory and executive function, language, immediate verbal memory, and long-term verbal memory) in subjects with bipolar depression.

Researchers recruited 50 adult participants diagnosed by board-certified psychiatrists with type I or II bipolar disorder (according to the DSM-IV), and who were experiencing a depressive episode of moderate severity at the time of the trial, which was randomized, double-blind, and sham-controlled. Of the 43 participants who finished the trial, 23 made up the sham group and 20 made up the active group. All subjects were on a stable pharmacological regimen during the trial—however, without concomitant antidepressant medications—and presented with resistant depression defined as failure to achieve remission.

The 8-week trial administered the H1-coil TMS intervention in 20 daily sessions during the first 4 weeks, followed by a 4-week period with no treatment sessions. The 6 cognitive domains were assessed using a battery of neuropsychological tests administered at baseline, and again at 4 and 8 weeks. In both sham and active groups, improvement was observed over time in all cognitive domains, suggesting that the H1-coil TMS treatment for bipolar depression is safe in terms of cognitive response.

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Although the study sought to additionally assess the relationship between depression improvement and cognitive improvement, the results did not support any correlation. This suggests that cognitive impairment is likely a feature of bipolar depression rather than a symptom. Trial limitations included a small study population, the absence of a healthy control group, as well as unmedicated participants.

Cognitive dysfunction in individuals with bipolar depression often persists even after intervention, and many pharmacological therapies increase cognitive dysfunction, contributing to a poor quality of life. The demonstration of cognitive safety for the H1-Coil TMS treatment provides a compelling option for managing bipolar depression.


Myczkowski ML, Fernandes A, Moreno M, et al. Cognitive outcomes of TMS treatment in bipolar depression: safety data from a randomized controlled trial [published online April 3, 2018]. J Affect Disord. doi: 10.1016/j.jad.2018.04.022