Use of a portable biofeedback device to improve insomnia in a combat zone, a case report.

Insomnia is a common problem in situations of stress. Some forms of stress, however, may contraindicate the use of traditional, pharmacological interventions. Working in a combat zone is such a situation. Alternative means of improving sleep are clearly needed for Service Members. We report a case involving a medical provider who was serving in a military, emergency-services facility in Iraq, and who presented with anxiety, depressed mood, and insomnia. Symptoms were sub-threshold for major depressive disorder or acute stress disorder. Mood and anxiety symptoms responded to traditional therapy techniques, but problems with insomnia remained. The patient was given a portable biofeedback device that employs an infrared sensor photoplethysmograph to measure heart rate variability (HRV) from peripheral finger pulse. One week later, sleep was significantly improved. Symptom improvement lasted to at least 6 weeks while in theater. One year later, a check-in with the patient revealed that after returning home, he had been diagnosed with post traumatic stress disorder (PTSD). PTSD symptoms had resolved after 6 months of psychopharmacology and cognitive behavioral therapy. These results indicate that biofeedback may be a useful means of improving sleep in a combat zone, but that such improvements may not necessarily prevent the development of more serious symptoms later. No clear causality can be inferred from a single case, and further study is needed to determine if this finding have wider applicability.