Does 18 Hz deep TMS benefit a different subgroup of depressed patients relative to 10 Hz rTMS? The role of the individual alpha frequency

• Published in: European neuropsychopharmacology 2024-12, Vol.89, p.73-81
• Main Authors: Voetterl, Helena, Alyagon, Uri, Middleton, Victoria J., Downar, Jonathan, Zangen, Abraham, Sack, Alexander T., van Dijk, Hanneke, Halloran, Aimee, Donachie, Nancy, Arns, Martijn
• Format: Article
• Language: English
• Subjects: Adult; Alpha Rhythm - physiology; Biomarker; Deep TMS; Depressive Disorder, Major - physiopathology; Depressive Disorder, Major - therapy; Electroencephalography; Electroencephalography - methods; Female; Humans; Male; Middle Aged; Stratified psychiatry; TMS; Transcranial Magnetic Stimulation - methods; Treatment Outcome
• ISSN: 0924-977X; 1873-7862; 1873-7862
• DOI: 10.1016/j.euroneuro.2024.09.007

•Individual alpha frequency represents a robust EEG biomarker in depression.•Depression patients with a 9 Hz alpha rhythm show worse response to 18 Hz deep TMS.•Alpha frequency-based biomarker can stratify patients to 3 different TMS protocols.•Endogenous oscillations at 9 Hz might not get entrained by 18 Hz harmonic frequency. Both 10 Hz repetitive transcranial magnetic stimulation (rTMS) as well as 18 Hz deep TMS (dTMS) constitute effective, FDA-approved TMS treatment protocols for depression. However, not all patients experience sufficient symptom relief after either of these protocols. Biomarker-guided treatment stratification could aid in personalizing treatment and thereby enhancing improvement. An individual alpha frequency (iAF)-based EEG-biomarker, Brainmarker-I, can differentially stratify patients to depression treatments. For instance, an iAF close to 10 Hz was associated with better improvement to 10 Hz rTMS, possibly reflecting entrainment of endogenous oscillations to the stimulation frequency. Accordingly, we examined whether 18 Hz dTMS would result in better improvement in individuals whose iAF lies around 9 Hz, a harmonic frequency of 18 Hz. Curve fitting and regression analyses were conducted to assess the relation between iAF and improvement. For treatment stratification purposes, correlations with iAF-distance to 10 Hz compared 18 Hz dTMS (N = 114) to 10 Hz rTMS (N = 72). We found a robust quadratic effect, indicating that patients with an iAF around 9 Hz exhibited least symptom improvement (r2=0.126, p