Transcranial Alternating Current Stimulation (tACS) for the Treatment of Anxiety in Veterans: An Open-Label Pilot Study

Transcranial alternating current stimulation (tACS) in a wearable brain stimulation device that delivers a low intensity, pulsed, alternating current via scalp electrodes. This device is regulated by the Food and Drug Administration (FDA) within the category of cranial electrotherapy stimulation. Prior sham-controlled clinical trials have shown the therapeutic effects and safety of tACS for the treatment of anxiety and depression. In addition, tACS is rapid acting and well tolerated. After the device is issued to the patient during an in-office orientation and training session, the tACS device can be safely used by the patient at the convenience of their own home. More research in Veteran populations and additional outcomes, such as neurocognitive and post-traumatic stress disorder (PTSD) symptoms, is warranted. Methods: Up to 40 Veterans under that age of 70 who have clinically significant anxiety will be enrolled in an 8-week open-label trial of Model FW-200 tACS to evaluate feasibility, acceptability, adherence and impact on anxiety, depression, PTSD, sleep and neurocognitive measures. Participants may have a concurrent diagnosis of major depressive disorder (MDD) and/or PTSD. They may remain on stable doses of existing antidepressants. After baseline assessment, Veterans meeting eligibility criteria will be trained on the use of the Fisher Wallace FW-200 Stimulator, a wearable, battery-powered (2 AA) tACS device comprised of a handheld pulse generator, 2 electrodes that attach to the pulse generator via wires, and an adjustable headband used to secure the electrodes. The tACS device delivers 2 mA (±10% tolerance) of pulsed alternating current, with a pulse width of 33.3 microseconds, using a rectangular, bipolar (bidirectional) waveform, employing a 15,000-Hz carrier frequency and 2 modulating frequencies of 500 Hz and 15 Hz, delivered through two 1.5-inch-diameter (circular) sponge electrodes moistened with tap water and secured under the headband at the squamous temporal bone above the posterior aspect of the zygomatic arch on either side of the head (i.e., center of each electrode located, respectively, at EEG coordinates FTT7h and FTT8h) . The device turns off automatically after each 20-minute treatment session. Participants will be trained in the use of the tACS and instructed to use it for 20 minutes in the morning and at bedtime (twice daily). Outcomes and self-reported adherence will be measured at 2, 4, 6, and 8 weeks. In addition to anxiety, depression and quality of life outcomes, neurocognitive measures will be collected to investigate a new area of possible improvement in Veterans. Significance: Testing a novel device that has shown preliminary effectiveness and safety in treating anxiety and depression in a Veteran population is important for advancing the care of Veterans.

Inclusion criteria

• Veteran of the U.S. military
• English-speaking and provides signed informed consent and HIPAA
• Adults ≤70 years of age
• Past week's GAD-7 of ≥10 which represents at least moderate level of anxiety
• If applicable, antidepressants may be continued if taking the concomitant medication for ≥8 weeks and at stable doses for ≥4 weeks
• Participants of child-bearing potential must have negative pregnancy test at entry and must agree to adhere to a medically acceptable method of birth control

Exclusion criteria

• Lifetime bipolar type I, schizophrenia spectrum, or other psychotic disorders based on VA medical records
• Current sedative-hypnotic, stimulant, inhalant and/or opioid use disorder within the past 6 months based on VA medical records and clinical interview
• Diagnosis of moderate to severe alcohol and/or cannabis use disorder within past 6 months based on VA medical records and clinical interview
• History of severe traumatic brain injury (TBI), defined by Ohio State University TBI Identification Method
• Dementia or related progressive neurocognitive disorder as per the medical record
• Use of prohibited medications (see list above) in the prior 2 weeks
• Increased risk of suicide that necessitates inpatient treatment, suicidal ideation/behavior endorsed on 6-item Columbia Suicide Severity Rating Scale screening questionnaire (yes" to question 4 or 5; or yes to # 6 as current), and/or suicidal behavior within past 90 days.
• Treatment with electroconvulsive therapy, vagus nerve stimulation, or transcranial magnetic stimulation within the past 6 months
• Implanted central nervous system devices (e.g. deep brain stimulation)
• Implanted cardiac pacemaker
• Trigeminal neuralgia that is currently symptomatic
• Treatment with evidence-based psychotherapy (EBP) for anxiety, depression or PTSD in the past 14 days. If receiving EBP therapy, he/she should complete EBP prior to entering study. Veterans currently engaged in non-EBP, e.g., supportive counseling or skills group therapies, may continue in these if they have been in this treatment for at least 4 weeks prior to baseline assessments.
• Pregnancy during treatment
• Clinically significant medical/surgical illness that would contraindicate use of tACS, e.g. unstable cardiac condition, those who fear electrical stimulation, presence of skin irritation or abrasions around either electrode site, or who have shrapnel fragments near either electrode site.
• Litigating for disability income for a mental disorder outside the VA compensation and pension process