Smartwatch vibration therapy tested for warfighter nightmares and insomnia

Copied word for word from the study's registry entry, so the wording is the study team's rather than ours.

Inclusion Criteria: * Defense Enrollment Eligibility Reporting System (DEERS) Eligible * Current or former military service member * Able to read and understand English language without the use of an interpreter * Habitual bedtime between 9:00 PM and 1:00 AM * Aged 18-62 (inclusive) * Able to commit to study procedures Exclusion Criteria: * Use of alpha or beta-receptor active medications or prescribed sleep aids in the last 3 months * Started use of SNRIs or SSRIs in the last 3 months * Pregnant * Receiving ongoing and extensive treatment for a new or acute psychiatric disorder within 90 days, other than routine follow-up and care * Starting concurrent evidence based psychiatric treatment within the past three months * Diagnosis of a serious medical condition (i.e., late-stage cancer or heart disease) * Routine night shift work in the past 3 months * Unstable neurological disease/autonomic disorders/ heart conditions/psych/ sleep or other unstable disorder as determined by the Principal Investigator/Associate * Investigators determined by clinical interview by Mini international neuropsychiatric interview and medical health questionnaire * Excessive alcohol use as determined by the AUDIT-C (AUDIT-C \> 3) * Started using any other medication (prescribed or over-the-counter) for the purpose of improving sleep in the last 90 days (e.g., barbiturates, benzodiazepines, melatonin, natural supplements and herbs, antidepressants, antihistamines, etc.) * Receiving treatment for substance use disorder within 90 days from the start of the study * Evidence of moderate or severe Obstructive Sleep Apnea (OSA): Determined by the STOP-BANG questionnaire: STOP-BANG greater than 5 Determined by EMR PSG records: moderate or severe OSA \[apnea-hypopnea index (AHI)≥15\] * Clinically significant suicidality as assessed by the Columbia-Suicide Severity Rating Scale (C-SSRS) * Currently participating in other research studies for improving sleep * Currently participating in other research studies for improving PTSD * Currently in therapy for the primary purpose of improving sleep (e.g., CBT-I) * Currently undergoing other treatment to improve sleep (e.g., acupuncture) * History or diagnosis of any of the following sleep disorders: narcolepsy, shift-work disorder or circadian rhythm disorders * Prone to problems with venipuncture including fainting, hematoma, and infection * Moderate and high nicotine dependence based on the Fagerstrom Test for Nicotine Dependence (\> 4 on the Fagerstrom Test for Nicotine Dependence) High caffeine dependence based on the Caffeine Dependence Questionnaire (\> 30 on the Caffeine Dependence Questionnaire) * Currently experiencing a neurological disorder (e.g., stroke, Parkinson's, MS, etc.) * Exclusion for optional MRI visit: Metal in body that is ferromagnetic / incompatible with MRI or other safety issues and indicated by screen Previous adverse reactions to sleep deprivation Illicit drug use as determined by participant self-report Alcohol in system at time of MRI overnight as determined participant self report Nicotine use in the last 3 months For poor sleep group: TBI History of epilepsy or suspected seizure disorder.