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Transcranial focused ultrasound targeting the default mode network for the treatment of depression

Jessica N. Schachtner, Jacob F. Dahill-Fuchel, Katja E. Allen, Christopher R. Bawiec, Peter J. Hollender, Sarah B. Ornellas, Soren D. Konecky, Achal S. Achrol, John J. B. Allen

Frontiers in Psychiatry 2025, 16 · 10.3389/fpsyt.2025.1451828

human patientdepressionother mriclinical scale

Abstract

Introduction Up to 50% of individuals fail to respond to current depression treatments. Repetitive negative thought and default mode network hyperconnectivity are central in depression and can potentially be targeted using novel neuromodulation techniques. This community-based study assessed whether a treatment using non-invasive transcranial focused ultrasound targeting the default mode network can decrease depression symptoms and repetitive negative thought, and improve quality of life. Methods Study recruitment began in August 2023 and ended in February 2024. Twenty individuals aged 18 - 50 were enrolled from among 247 screened. Exclusion criteria included history of psychosis/mania, acute suicidality, MRI contraindications, pregnancy, and medical and neurological factors that may complicate diagnosis or brain function. Participants completed up to three weeks of transcranial ultrasound (11 sessions) targeting the anterior medial prefrontal cortex; ten minutes per session. Depression severity (Beck Depression Inventory - II and the Hamilton Depression Rating Scale), repetitive negative thought (Perseverative Thinking Questionnaire), and quality of life (World Health Organization Quality of Life Scale) were outcomes. Results This sample was young (mean 30.4 years ± 10.0), predominantly female (75%), with moderate to severe depression and high comorbidity. Fifty percent of participants endorsed current psychiatric medication use. Ten percent of subjects dropped out of the study due to time constraints. Significant decreases in depression were observed over the course of treatment on self-report, 10.9 (p Discussion Non-invasive transcranial focused ultrasound holds promise as a treatment for depression holds promise as a treatment for depression, however, future work including control arms is required to ascertain its causal role in depression. Clinical trial registration https://clinicaltrials.gov/study/NCT06320028intr=Ultrasound&cond=depression&locStr=Arizona&country=United%20States&state=Arizona&rank=1, identifier NCT06320028.

Abstract via europepmc.

Specieshuman
Subjects20 participants
Sessions per subject11
Randomisedno
Blindingnone
Sham / controlnone
Auditory controlnot reported
Readout timingoffline
Anaesthesianot applicable
Readoutsother mri, clinical scaleBeck Depression Inventory-II (BDI-II); Hamilton Depression Rating Scale (HDRS); Perseverative Thinking Questionnaire (PTQ); World Health Organization Quality of Life Scale (WHOQOL-BREF); Columbia Suicide Severity Rating Scale (CSSRS); post-session sensation questionnaire
Direction of effectnot assessedFunctional connectivity was not measured in this study; the authors hypothesize (but did not test) that the low PRF (10 Hz) and low acoustic frequency (400 kHz) parameters used promoted an inhibitory effect on DMN connectivity.
Adverse eventsobservedNo serious adverse events were reported; participants reported mild, transient sensations (mean ratings below 2.2 on a 10-point scale), with pain/tension attributed to headset tightness rather than the ultrasound itself; SWI imaging showed no treatment-related microhemorrhages.

Exposures

Exposure 1: amPFC tFUS for depression

Target: anterior prefrontal cortex — “left anterior-medial prefrontal cortex (amPFC)
Device: Openwater · Openwater · custom Neuromodulation device, 128-element ultrasound array

Pulse timing
Waveformpulsed
Fundamental frequency (kHz)400✓✓
Pulse duration (ms)5✓✓
Pulse repetition frequency (Hz)10✓✓
Duty cycle (%)not reportedpulse duration × PRF gives 5%
Sonication duration (s)600✓✓
Pressure and intensity, by domain
Free-field pressure (kPa)not reported
Free-field Isppa (W/cm²)not reported
Free-field Ispta (W/cm²)not reported
In-situ estimatenot reported
In-situ pressure (kPa)not reported
In-situ Isppa (W/cm²)not reported
In-situ Ispta (W/cm²)not reported
Pressure, domain unspecified (kPa)820✓✓
Ispta, domain unspecified (W/cm²)0.67✓✓
Protocol, in the paper’s words

Participants completed up to three weeks of transcranial ultrasound (up to 11 sessions total: 5 sessions in week 1, then, for those not meeting early-remission criteria, 3 sessions per week for two more weeks), each session lasting ten minutes, targeting the left amPFC via electronically-steered beam-forming with a multi-foci radial pattern of five sub-foci.

Flags from extraction

  • n_sessions_per_subjectThe protocol allowed early termination after 5 sessions (week 1) if remission criteria were met, so not all participants completed all 11 sessions; recorded 11 as the designed maximum stated in the abstract/methods.
  • exposures[0].target.termsThe paper's own target name is 'anterior-medial prefrontal cortex (amPFC)'; mapped to 'anterior_prefrontal_cortex' (frontopolar/BA10, closest listed term given the anterior MNI y-coordinate of 45) rather than 'ventromedial_prefrontal_cortex', though the paper's wording ('medial prefrontal') could also support the latter; flagged for review.
  • exposures[0].timing.duty_cycle_pctDuty cycle is not explicitly stated as a percentage in the text (only pulse duration = 5 ms and PRR = 10 Hz are given); left not_reported rather than computed.
  • exposures[0].unspecified_domain.pressure_kpaPeak negative pressure (820 kPa) and spatial-peak/temporal-average intensity (670 mW/cm2) are given without stating whether they are free-field (water) or in-situ (skull-corrected) values; recorded as unspecified_domain.
  • direction_of_effectFunctional connectivity/DMN modulation was not measured in this study; the inhibitory direction is the authors' hypothesis based on stimulation parameters, not a measured outcome.