Neural Noise

High-definition tDCS for chronic insomnia: randomized controlled trial

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  • A randomized, double-blind, controlled trial evaluated high-definition transcranial direct current stimulation (HD-tDCS) for the treatment of chronic insomnia.1
  • The trial adds evidence on dosing and indications for non-invasive neuromodulation.1
  • Results are relevant for device and clinical trial design (Nature; tier-1).1 1

Weekly enrichment (2026-07-20)

  • The primary study is a randomized, double-blind, sham-controlled trial published in Scientific Reports (Nature); 55 chronic-insomnia patients were analyzed (27 active, 28 sham) after three dropouts.2
  • Protocol: high-definition tDCS over the dorsomedial prefrontal cortex (DMPFC) with the anode at Fz (+2.0 mA) and four surrounding cathodes at FPz, F3, Cz, and F4 (−0.5 mA each), delivered 30 minutes/day for 10 consecutive days via a Neuroelectrics stimulator.2
  • Primary outcomes were the Pittsburgh Sleep Quality Index (PSQI) and Flinders Fatigue Scale (FFS); the active group showed a significant PSQI reduction from day 1 to day 10 (t = 8.298, p < 0.001) and FFS improvement (t = 3.232, p = 0.003), with a significant time×group effect favoring active stimulation on total PSQI (F = 5.559, p = 0.022).2
  • Objective polysomnography (secondary): sleep onset latency shortened (t = 2.421, p = 0.023) and sleep efficiency improved (t = −2.371, p = 0.025) in the active group (group effect on SOL F = 10.898, p = 0.002); total sleep time, wake-after-sleep-onset, and sleep-stage ratios were unchanged.2
  • The sham group also improved subjectively (a notable placebo response), and 44/55 patients had previously used non-benzodiazepine hypnotics; prior pharmacotherapy did not explain the PSQI, SOL, or SE changes.2
  • The companion ClinicalTrials.gov registration (NCT06290492) documents the same 2 mA dmPFC montage, triple masking, and ~45 enrolled participants.3
  • Context: chronic insomnia is characterized by cortical hyperarousal, and an earlier bifrontal anodal tDCS study found no sleep benefit in patients, with baseline arousal predicting non-response—motivation for targeting the DMPFC.4
  • Context: a systematic review notes non-invasive brain stimulation can modulate cortical excitability and oscillations relevant to hyperarousal, but the insomnia evidence base remains small and heterogeneous.5
  • Context: a 2025 SLEEP meeting RCT (n = 87) found tDCS/tACS PSQI improvements statistically indistinguishable from sham, underscoring the need for replication.6
  • Context: a recent resting-state fMRI RCT links tDCS benefits in insomnia with comorbid anxiety to enhanced global BOLD–cerebrospinal-fluid (glymphatic) coupling, suggesting a candidate mechanism.7

Footnotes

  1. https://news.google.com/rss/articles/CBMiX0FVX3lxTE00REZZaVVzZTRaczB5UzBkcGU1VU5oMnhDM2RqQm1rZUgyei1IZXd2UHJFWUFaZ21sWGZQdVVSU2xaSFg1WUJDaDA4cFBVQk5vUmsxRGhsTmUyTjNzeXdz?oc=5 ↩ ↩2 ↩3 ↩4

  2. https://www.nature.com/articles/s41598-025-09304-4 ↩ ↩2 ↩3 ↩4 ↩5

  3. https://clinicaltrials.gov/study/NCT06290492 ↩

  4. https://www.brainstimjrnl.com/article/S1935-861X(19)30001-4/abstract ↩

  5. https://pmc.ncbi.nlm.nih.gov/articles/PMC10909439/ ↩

  6. https://www.neurologylive.com/view/negative-study-findings-further-question-effectiveness-transcranial-direct-stimulation-treat-insomnia ↩

  7. https://link.springer.com/article/10.1186/s12888-026-08304-6 ↩

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