Three-Minute ‘Theta Burst’ Treatment as Effective as 37-Minute RTMS
A variation on repeated transcranial magnetic stimulation (rTMS) called intermittent theta burst stimulation (iTBS) may be able to deliver the same benefits in a tenth of the time. RTMS is a non-invasive treatment in which a magnetic coil placed near the skull transmits electrical signals to the brain. It is effective in depression and has been shown to improve aspects of schizophrenia, autism, and addictions as well.
A typical rTMS session lasts for 37.5 minutes and consists of high frequency (10 Hz) stimulation. Access to the treatment remains somewhat limited, so the newer form of iTBS treatment may help more people access treatment by allowing clinicians to treat more patients in a day.
The 2018 study, published by Daniel Blumberger and colleagues in the journal The Lancet, compared iTBS to standard rTMS and evaluated the effectiveness, safety, and tolerability of the new treatment compared to the old. 414 patients aged 18–65 with major depression that had persisted despite treatment with several antidepressant options were randomized to receive either iTBS or rTMS delivered to their left dorsolateral prefrontal cortex. They received the given treatment five days/week for four to six weeks.
Patients who received iTBS showed a nearly identical level of improvement in depression to those who received rTMS. Self-reports of pain intensity were worse among those who received iTBS, but the dropout rate was not higher for that group. Headaches were the most common side effect reported, and rates were similar across both groups. The authors judged iTBS to be a comparable, non-inferior alternative to rTMS for people with major depression.
Among participants who received iTBS, depression improved significantly, with 32 percent reporting a remission of depression symptoms. Those who received standard rTMS had a remission rate of 27 percent.
Theta-burst RTMS Improved Depression
Theta-burst stimulation is a type of repeated transcranial magnetic stimulation (rTMS) currently being investigated for the treatment of severe depression. In rTMS a magnetic pulse applied to the scalp causes neurons to fire. A recent study of 60 patients by Cheng-Ta Li et al. published in the journal Brain compared continuous, intermittent, and combined theta-burst treatment with a sham treatment. While all four groups of patients with treatment-resistant depression improved, indicating some placebo effect, patients in the group who received intermittent stimulation over the left prefrontal cortex and those who received a combination of intermittent left prefrontal cortex stimulation and continuous right prefrontal stimulation showed the greatest improvement in their depression. Those patients with greater prior treatment resistance responded less well across all of the treatments.
Editor’s Note: Studies continue to explore the optimum parameters for rTMS, but large studies and meta-analyses continue to show that the treatment has positive effects in depression.
