An interventional study of Transcutaneous Auricular Vagus Nerve Stimulation (taVNS) and Sham Transcutaneous Auricular Vagus Nerve Stimulation (sham-taVNS) in Generalized Anxiety Disorder (GAD), sponsored by Birjand University of Medical Sciences. Not yet recruiting. Open to participants aged 18 Years to 65 Years. Per ClinicalTrials.gov, last updated 2026-11-12.
Sponsored by Birjand University of Medical Sciences · Not applicable, Interventional, and Treatment
The goal of this feasibility clinical trial is to learn whether a small device that stimulates a nerve in the outer ear can be safely and practically used at home by adults with generalized anxiety disorder (GAD). The study will also explore whether this treatment may help lower anxiety and improve sleep quality. Participants will be adults aged 18 to 65 years in Birjand, Iran.
The main questions it aims to answer are:
Researchers will compare active stimulation with sham stimulation. Sham stimulation is a comparison procedure designed to resemble the active treatment but does not deliver the same active stimulation. This comparison will help researchers explore possible treatment effects and assess whether a larger study is practical.
Participants will:
518 studies on the registry are indexed under Generalized Anxiety Disorder; 125 are open to participants now.
This study's planned enrollment of 40 is below the median of 83 across 440 interventional studies indexed under Generalized Anxiety Disorder.
Browse Generalized Anxiety Disorder studies →Birjand University of Medical Sciences is the lead sponsor of 8 studies on the registry; 2 are open to participants now.
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Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.
Exclusion Criteria:
Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
The American Psychiatric Association’s manual of mental health diagnoses. DSM-5 (2013, revised as DSM-5-TR in 2022) replaced DSM-IV, and some studies still name the older edition. “Meets DSM criteria for …” means diagnosed by that edition’s diagnostic criteria, usually by a clinician in an interview.
DSM diagnostic criteria
The American Psychiatric Association’s manual of mental health diagnoses. DSM-5 (2013, revised as DSM-5-TR in 2022) replaced DSM-IV, and some studies still name the older edition. “Meets DSM criteria for …” means diagnosed by that edition’s diagnostic criteria, usually by a clinician in an interview.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Device: Sham Transcutaneous Auricular Vagus Nerve Stimulation (sham-taVNS)
Device: Transcutaneous Auricular Vagus Nerve Stimulation (taVNS)
Participants assigned to the active intervention group will use a transcutaneous auricular vagus nerve stimulation (taVNS) device at home for four weeks. Stimulation will be administered daily according to the study protocol. Participants will receive instructions on device use and will wear a monitoring wristband to help track adherence and selected physiological measures. Safety, tolerability, usability, and adherence will be assessed during the study. Assessments will take place at weeks 2 and 4, with follow-up at weeks 6 and 8
Participants assigned to the sham control group will use the taVNS device at home for four weeks, following the study protocol. Stimulation will be delivered at the same site as in the active intervention group, but at a current intensity below 0.1 mA, as specified in the protocol. This sham procedure is intended to provide a comparison condition while helping maintain participant blinding. Participants will receive instructions on device use, and adherence, safety, and tolerability will be assessed during the study. Assessments will take place at weeks 2 and 4, with follow-up at weeks 6 and 8.
Change in Anxiety Severity Measured by the Hamilton Anxiety Rating Scale (HAM-A)
Anxiety severity will be assessed using the Hamilton Anxiety Rating Scale (HAM-A), a 14-item clinician-administered scale designed to evaluate the severity of anxiety symptoms. Each item is scored from 0 (not present) to 4 (very severe), yielding a total score ranging from 0 to 56, with higher scores indicating greater anxiety severity. The change in total HAM-A score from baseline to Week 8 will be calculated and compared between the active taVNS and sham stimulation groups. A greater reduction in score indicates a greater improvement in anxiety severity.
Time frame: Baseline to Week 8
Change in Sleep Quality Measured by the Pittsburgh Sleep Quality Index (PSQI)
Sleep quality will be assessed using the Pittsburgh Sleep Quality Index (PSQI), a validated self-reported questionnaire consisting of 19 items that evaluate sleep quality and disturbances over the previous month. The questionnaire generates seven component scores, which are summed to produce a global score ranging from 0 to 21. Higher scores indicate poorer sleep quality. The change in the global PSQI score from baseline to Week 8 will be calculated and compared between the active taVNS and sham stimulation groups. A greater reduction in score indicates an improvement in sleep quality.
Time frame: Baseline to Week 8
Incidence of Adverse Events During the Intervention Period
The safety and tolerability of transcutaneous auricular vagus nerve stimulation (taVNS) will be evaluated by monitoring adverse events throughout the intervention period. The number and proportion of participants experiencing at least one adverse event will be recorded in each study group. All reported adverse events will be documented, including their type, severity, duration, and potential relationship to the assigned stimulation intervention.
Time frame: Baseline through Week 8
Adherence to the Assigned Stimulation Protocol
Adherence to the assigned stimulation protocol will be assessed based on the proportion of prescribed stimulation sessions successfully completed by each participant during the 4-week intervention period. The number of completed sessions will be recorded and compared with the total number of prescribed sessions. Adherence will be expressed as a percentage, calculated as the number of completed sessions divided by the total number of prescribed sessions, multiplied by 100. Higher percentages indicate better adherence to the intervention protocol.
Time frame: 4 weeks
Success of participant blinding to treatment allocation in the active and sham stimulation groups
The success of participant blinding will be evaluated at the end of the intervention period. Participants will be asked to indicate whether they believe they received active taVNS or sham stimulation. The proportion of participants in each group who correctly and incorrectly identify their assigned intervention will be calculated to assess the effectiveness of participant blinding.
Time frame: at week 4 (end of intervention)
No study locations are listed for this record.
Start is estimated for Nov 2026; primary completion for May 2028, 18 months later.
Of 174 non-industry interventional studies with no phase under Generalized Anxiety Disorder, half reached primary completion within 29 months of starting (the median), counting those still running; a quarter within 16 and three quarters within 55. This study's planned 18 months is below that.
Counting every sponsor, half of 183 studies reached it within 28 months; a quarter within 15 and three quarters within 53.
How these figures are worked out, and which studies are left out of them.
From the registry record's own update history. This site started tracking changes on Sep 25, 2026; for anything earlier, see the record history on ClinicalTrials.gov ↗
This study is not yet recruiting, as verified in Nov 2026. You cannot join it, but the record below documents what was studied.
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Generalized Anxiety Disorder →
Birjand University of Medical Sciences