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Abstract
Increasing scientific evidence point to a non-pharmacological
complementary treatment for insomnia: white noise. Its presenta-
tion has been shown to induce sleep in human neonates and adults,
probably by reducing the signal-to-noise ratio of ambient sound.
White noise may be a simple, safe, cost-effective alternative to
hypnotic medication in many psychiatric disorders, especially acute
stress disorder and PTSD.
Sleep dysfunction is common among people with acute stress
disorder, posttraumatic stress disorder (PTSD), as well as most other
mood and anxiety spectrum disorders, both in the primary care
setting and in specialty clinics. Patients report difficulty falling
asleep, are easily awakened, and may suffer from disturbing, un-
pleasant nightmares.
1
Indeed, two of the major symptom criteria for
PTSD, re-experiencing and hyperarousal, are negatively related to
sleep regulation.
2
Re-experiencing phenomenon may include intru-
sive thoughts and images of the traumatic event that prevent indi-
viduals from falling asleep and distressing nightmares that wake
them. Similarly, enhanced arousal may lead to difficulty in falling
asleep (perhaps due to hypervigilance), as well as increase the
probability of nighttime awakenings provoked by an exaggerated
startle response to external stimuli that do not penetrate the con-
sciousness of normal individuals.
Primary care clinicians often prescribe hypnotics such as benzo-
diazepines, in addition to the pharmaceutical regimen directed at the
underlying disorder, to psychiatric patients who suffer from insom-
nia. The difficulties and harm that can ensue from benzodiazepine
administration are well documented. As such, there is growing
interest in adjunctive and integrative biological approaches in medi-
cine, and there may be safer alternatives that deserve greater
research and clinical attention.
Evidence Based Complementary
Intervention for Insomnia
Hassan H. Lopez PhD, Adam S. Bracha BA, and H. Stefan Bracha MD
One intriguing possibility is the controlled presentation of white
noise, which may possess hypnotic properties. To date, only a few
controlled experiments have tested the sleep utility of low-intensity,
consistent auditory stimulation. White noise has been shown to
effectively induce sleep in human neonates between the ages of two
and seven days.
3
Eighty percent of those neonates exposed to white
noise fell asleep within five minutes, compared to a spontaneous rate
of 25%. Simulated music composed of white noise also induces
sleepiness and higher delta component power densities (measured
via EEG) in adult subjects, suggesting that it has the capacity to alter
overall level of arousal and state of consciousness.
4
Another study
tested the clinical effectiveness of white noise in a sample of
postoperative coronary artery bypass graft (CABG) patients, fol-
lowing their transfer from an intensive care unit.
5
Subjects exposed
to ocean sounds (composed of white noise) for three nights reported
experiencing significantly better sleep, in terms of sleep depth,
number of awakenings, ease of return to sleep, quality of sleep, and
total sleep, when compared to subjects not given white noise
treatment.
Presumably, white noise functions to reduce signal-to-noise ratio,
and thus promote decreased arousal and prevent sleep interruption.
Very simply, invariable, low-intensity auditory stimulation could
mask the perception of normally disrupting nighttime noises, such
as wind, car-alarms or voices. This could be particularly useful for
victims of acute stress disorder and PTSD, by serving as an effective
startle-prevention tactic. Interestingly, it has been shown that the
presentation of white noise reduces norepinephrine concentration in
the auditory pathways of rats.
6
Given this neurotransmitter’s in-
volvement in arousal, stress and the etiology of PTSD,
7
it is possible
that white noise may have a direct therapeutic effect on certain
stress-mediated disorders. For several years now, many PTSD
experts in the VA healthcare system have been advising their
patients to sleep with a fan on to induce sleep, and unpublished
anecdotal reports from patients in the VA regarding the effective-
ness of this simple suggestion have been encouraging. A more
precise strategy would be the use of standardized, wide-spectrum
white noise, currently available in CD format
(www.whitenoisecd.com) as a complementary intervention for in-
somnia.
8
Clearly, a prescription of white noise possesses strong advantages
over benzodiazepines in terms of both safety and cost. We would
like to suggest that more research be conducted on the effectiveness
of white noise as a sleep-aid for psychiatric patients, as well as on the
neurophysiological mechanism behind its potential function.
Correspondence to:
H. Stefan Bracha MD
Research Psychiatrist
National Center for PTSD
Department of Veterans Affairs,
Spark M. Matsunaga Medical and Regional Office Center
1132 Bishop St., Suite 307
Honolulu, HI 96813
Telephone: (808) 566-1652
Fax: (808) 566-1885
Email: H.Bracha@med.va.gov
Continues on next page
HAWAII MEDICAL JOURNAL, VOL 61, SEPTEMBER 2002
163
Authors
National Center for PTSD, Department of Veterans Affairs, Spark
M. Matsunaga Medical and Regional Office Center, Honolulu,
Hawaii
Acknowledgements
This material is the result of work supported with resouces and the use of facilities
at the Spark M. Matsunaga VA Medical and Regional Office Center, Honolulu,
Hawaii. Support was also provided by a National Alliance for Research on Schizo-
phrenia and Depression (NARSAD) independent investigator award to Dr. Bracha.
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