Connectivity- vs Scalp-Based Targeting of Accelerated Transcranial Magnetic Stimulation for Depression: A Randomized...

Area of Science:

• Neuroscience
• Psychiatry
• Medical Imaging

Background:

• Neuroimaging is widely used in psychiatric research, but its clinical outcome benefits are not well-established.
• Functional connectivity neuroimaging has been used to guide accelerated transcranial magnetic stimulation (aTMS) for rapid antidepressant effects, but the necessity of connectivity-based targeting is unclear.

Purpose of the Study:

• To determine the effect size of using functional connectivity versus scalp-based targeting for aTMS in patients with treatment-resistant depression.

Main Methods:

• A randomized clinical trial involving 40 adults with treatment-resistant major depressive disorder.
• Participants received either connectivity-based or scalp-based aTMS, with targets identified using resting-state functional connectivity scans or the Beam F3 method, respectively.
• Blinded assessment of the primary outcome, depression severity (Montgomery-Åsberg Depression Rating Scale - MADRS), at 1 month post-treatment.

Main Results:

• Connectivity-based targeting resulted in a median MADRS score reduction of 24 points, compared to 18 points for scalp-based targeting (P=.02).
• The effect size for connectivity-based targeting was 0.8 (Cohen d analog), with a number needed to scan of 5.
• Individualized targets showed high reproducibility within subjects and significant differences between subjects.

Conclusions:

• Individualized, connectivity-based targeting of the convergent depression circuit significantly enhanced the antidepressant effects of high-dose aTMS.
• These findings suggest that connectivity-based targeting is a crucial component for optimizing aTMS efficacy in treatment-resistant depression.
• The results support the use of this approach in future cost-effectiveness and confirmatory efficacy trials.