Efficacy, Tolerability, and Cognitive Effects of Deep Transcranial Magnetic Stimulation for Bipolar Depression

Efficacy, Tolerability, and Cognitive Effects of Deep Transcranial Magnetic Stimulation for Bipolar Depression: a Double-blind, Randomized Controlled Trial

The aim of this study is to evaluate the feasibility and efficacy of deep transcranial magnetic stimulation (dTMS) as an add-on treatment for bipolar depression. Meanwhile, we aim to evaluate the effect of dTMS on cognitive function of bipolar depressive patients. We hypothesize dTMS would improve depressive symptoms and cognitive function in bipolar disorder.

This is a randomized, double-blind, sham-controlled study to detect the effect of dTMS for treatment of bipolar depression. 100 participants were randomly assigned 1:1 to dTMS group or sham-control group. For both active and sham group, daily dTMS sessions were scheduled in a 5-day sequence for four consecutive weeks, and each session lasted 20minutes. Based on the original and stable medication, the active stimulation consisted of 55 18 Hz, 2 s trains at 120% motor threshold (MT) intensity, with a between-train interval of 20 s (1980 pulses per day or 39 600 pulses per treatment). The sham stimulation was performed using the same procedures, with the sham coil.

Scale assessments are performed at baseline, week 2, week 4 and week 8. Collection of blood took place at baseline, week 4 and week 8.

Inclusion Criteria:

Confirmed diagnosis of bipolar depression;

• age between 18 and 65 years;
• a 17-item Hamilton Depression Rating Scale (HDRS-17) score >= 17,
• a stable pharmacological regimen maintained for at least 4 weeks prior to the beginning of the treatment phase ;
• for participants who had previously received antidepressant therapy, a minimum 4-week washout period followed by re-evaluation.

Exclusion Criteria:

• a lifetime history of other psychiatric disorders, neurological diseases, or severe brain injury;
• receipt of electroconvulsive therapy, rTMS, transcranial direct current stimulation, transcranial alternating current stimulation, or other neurostimulation treatments within the previous 3 months;
• contraindications to magnetic stimulation, including epilepsy, cardiovascular disorders, or metallic implants in the head;
• the presence of hypomanic/manic symptoms at baseline or a score greater than 12 on the Young Mania Rating Scale (YMRS);
• pregnancy or lactation.