Trial results for a study evaluating closed-loop transcranial alternating current stimulation (tACS) for Depression were posted on ClinicalTrials.gov on 2025-05-29, showing a mean reduction of 12.04 units on the Hamilton Depression Rating Scale 17-item (HDRS-17) in one measurement, and significant changes in other depression scales.
Background
Depression, particularly Major Depressive Disorder (MDD), is a widespread and debilitating mental health condition characterized by persistent sadness, loss of interest, and a range of emotional and physical problems. It affects millions worldwide and can significantly impair daily functioning and quality of life. While various treatments exist, including psychotherapy and pharmacotherapy, a substantial portion of patients do not achieve full remission or experience intolerable side effects. This highlights the ongoing need for alternative and adjunctive therapies. Transcranial alternating current stimulation (tACS) is a non-invasive brain stimulation technique that delivers weak electrical currents to the scalp to modulate brain activity, offering a potential therapeutic avenue for conditions like depression by targeting specific brain oscillations.
Trial design
This completed study investigated closed-loop transcranial alternating current stimulation (tACS) for the treatment of depression. The trial enrolled 26 participants diagnosed with Depression and Major Depressive Disorder. The study was designated as Phase NA. The intervention involved closed-loop tACS, which aims to adapt stimulation in real-time based on brain activity. The primary purpose was to determine the effects of this specific tACS approach on symptoms of depression.
Key results
The trial results indicate significant changes in depression symptom scales following closed-loop tACS:
- Change in Hamilton Depression Rating Scale 17-item (HDRS-17): The mean change was -12.04 units on a scale (Standard Deviation: 4.83) in one measurement. Another measurement showed a mean change of -8.36 score on a scale (Standard Deviation: 4.41).
- Change in Quick Inventory of Depressive Symptomatology (QIDS): The mean change was -3.88 score on a scale (Standard Deviation: 3.23) in one measurement. Another measurement showed a mean change of -5.96 score on a scale (Standard Deviation: 3.51).
- Response/Remission of Depression: Counts of participants achieving response/remission included 12, 13, 21, 4, 10, 15, 21, and 4 participants across various assessments.
Key analyses further supported these observations:
- HDRS-17 change scores from Day 1 (D1) to Follow-up 2 (FU2) were submitted to a t-test, 2-sided, yielding a p-value of 0.0005, indicating a significant difference from zero (no change).
- HDRS-17 change scores from Day 1 (D1) to Day 5 (D5) were also submitted to a t-test, 2-sided, with a p-value of 0.0005, suggesting a significant change.
- QIDS change scores were analyzed using a repeated measures ANOVA, which resulted in a p-value of 0.0005, indicating significant change from baseline over time (D1, D5, FU1, FU2).
- Similar ANOVA analyses for ASRM, SHAPS, and DASS-42 OVERALL scores also yielded a p-value of 0.0005, suggesting significant changes from baseline over time.
What this means
The posted results suggest that closed-loop transcranial alternating current stimulation (tACS) may be an effective intervention for reducing symptoms of depression. The observed mean reductions in HDRS-17 scores, particularly the -12.04 unit change, along with significant changes in QIDS and other scales, indicate a meaningful clinical effect. The consistent p-value of 0.0005 across multiple analyses for HDRS-17 and other scales reinforces the statistical significance of these findings. While the study enrolled a relatively small number of participants (26) and the absence of a control arm in the provided data limits direct comparative conclusions, these results offer promising preliminary evidence for closed-loop tACS as a non-invasive treatment option for individuals with Major Depressive Disorder. Further research with larger, controlled trials would be beneficial to confirm these findings and establish the long-term efficacy and safety profile of this intervention.
Source
The information regarding these trial results was obtained from ClinicalTrials.gov, a public database of clinical studies. The results for the study NCT05772702, titled "Closed-Loop Transcranial Alternating Current Stimulation for the Treatment of Depression", were posted on 2025-05-29 on clinicaltrials.gov.