Developing and evaluating a firefighter self-administered neurostimulation intervention for traumatic stress to reduce alcohol use

The National Institute on Alcohol Abuse and Alcoholism awarded the University of Cincinnati Sponsored Research Services Division $228,118 on May 1, 2026, under the Alcohol Research Programs grant program (CFDA 93.273) to develop and evaluate a firefighter self-administered neurostimulation intervention for traumatic stress and alcohol use disorder.

The project develops a Phase II randomized clinical trial protocol testing transcutaneous auricular neurostimulation (TAN) of the vagus nerve as an intervention to reduce posttraumatic stress symptoms driving heavy alcohol use in firefighters with concurrent alcohol use disorder. Year 1 involves collaboration with a firefighter community advisory board to design a culturally informed protocol. Year 2 conducts a feasibility trial with 20 firefighters using the SPARROW device—a patient-administered, ear-worn device delivering electrical stimulation to branches of the vagus and trigeminal nerves—to evaluate protocol acceptability, feasibility, and intervention appropriateness. Year 3 completes an FDA pre-submission with the revised protocol to support a PTS/AUD indication for SPARROW ASCENT and finalizes the protocol with FDA feedback to support a subsequent R01 application for a fully powered Phase II RCT. Participants will use the SPARROW device for at least one hour per day, five days per week, during a four-week treatment phase.

Work is performed in Cincinnati, Ohio. The period of performance runs from May 1, 2026, through April 30, 2029. Sub-recipients include Spark Biomedical Inc., providing the SPARROW neurostimulation device, and the University of Kansas, contributing to protocol development and trial execution.

Abstract

Background. Firefighters are repeatedly exposed to potentially traumatic events and many experience posttraumatic stress (PTS) symptoms as a result. Over 50% of firefighters report past-month heavy alcohol use and many use alcohol to "self-medicate" from symptoms of hyperarousal, intense negative affect, and insomnia that follow traumatic events. Transcutaneous auricular neurostimulation (TAN) of the vagus nerve has shown promise for alleviating symptoms of PTS and opioid withdrawal symptoms but its effects have yet to be tested in a sample of firefighters with alcohol use disorders (AUD) and CO-occurring PTS symptoms. Aims. We will collaborate with a firefighter community advisory board to develop a culturally informed, phase II randomized clinical trial (RCT) protocol testing TAN as an intervention that may reduce PTS symptoms driving heavy alcohol use for firefighters with AUD (aim 1; year 1). We will then conduct a feasibility trial of the protocol (aim 2; year 2; N = 20) using the sparrow device-a patient-administered, ear worn device that delivers electrical stimulation to branches of the vagus and trigeminal nerves-to evaluate the acceptability and feasibility of the protocol, and the appropriateness of the TAN intervention for firefighters with PTS/AUD. Using data from the feasibility study, we will complete an FDA pre-submission with the revised trial protocol to support a PTS/AUD indication for sparrow ascent, finalize the protocol with FDA feedback, and write an R01 application for a fully powered phase II RCT (aim 3; year 3). Methods. The feasibility trial will recruit firefighters who engage in heavy drinking, have at least a mild AUD, and report above-average PTS symptoms. Participants will use the sparrow device for at least 1 hour/day for 5 days/week throughout the 4-week treatment phase, but may use the device more often if they wish. Participants in the active TAN condition (N = 10) will receive therapeutic stimulation from sparrow; active sham participants (N = 10) will feel stimulation at the trigeminal site only, but below a therapeutic level. They will complete daily measures of traumatic event exposure (number and type), PTS symptom severity, alcohol use (standard drinks) and motivations (trauma-related drinking), and audio journals capturing their experience with symptoms and the device (e.g., helpfulness). Additionally, wearable sensors will record heart rate, heart rate variability, and sleep data throughout the intervention phase. Assessments immediately following treatment (week 4) and one month later (week 8) will measure protocol feasibility and TAN's clinical effects outcomes including insomnia, mental health symptoms, and quality of life. Outcomes. The primary feasibility outcome is the mean of protocol ratings on the feasibility of intervention measure. Secondary feasibility outcomes include ratings of protocol acceptability (acceptability of intervention measure) and sparrow ascent appropriateness (intervention appropriateness measure). Exploratory clinical outcomes include reductions in PTS symptom severity scores and heavy drinking events.