Belleville G, Guay S, Marchand A Impact of sleep disturbances on PTSD symptoms and perceived health. J Nerv Ment Dis. 2009 Feb;197(2):126-32. doi: 10.1097/NMD.0b013e3181961d8e.
El-Sherbini AM, Bediwy AS, El-Mitwalli A Association between obstructive sleep apnea (OSA) and depression and the effect of continuous positive airway pressure (CPAP) treatment. Neuropsychiatr Dis Treat. 2011;7:715-21. doi: 10.2147/NDT.S26341. Epub 2011 Dec 13.
Hoge CW, Terhakopian A, Castro CA, Messer SC, Engel CC Association of posttraumatic stress disorder with somatic symptoms, health care visits, and absenteeism among Iraq war veterans. Am J Psychiatry. 2007 Jan;164(1):150-3.
Johns MW A new method for measuring daytime sleepiness: the Epworth sleepiness scale. Sleep. 1991 Dec;14(6):540-5.
Kang HK, Natelson BH, Mahan CM, Lee KY, Murphy FM Post-traumatic stress disorder and chronic fatigue syndrome-like illness among Gulf War veterans: a population-based survey of 30,000 veterans. Am J Epidemiol. 2003 Jan 15;157(2):141-8.
Kessler RC, Berglund P, Demler O, Jin R, Merikangas KR, Walters EE Lifetime prevalence and age-of-onset distributions of DSM-IV disorders in the National Comorbidity Survey Replication. Arch Gen Psychiatry. 2005 Jun;62(6):593-602. Erratum in: Arch Gen Psychiatry. 2005 Jul;62(7):768. Merikangas, Kathleen R [added].
Kulka RA, Schlenger WA, Fairbanks JA, et al Trauma and the Vietnam War generation: report of findings from the National Vietnam Veterans Readjustment Study (1990). New York: Brunner/Mazel.
Weathers F, Litz B, Herman D, et al (October 1993). The PTSD Checklist (PCL): Reliability, validity, and diagnostic utility. Paper presented at the Annual Convention of the International Society for Traumatic Stress Studies, San Antonio, TX.
Webber MP, Lee R, Soo J, Gustave J, Hall CB, Kelly K, Prezant D Prevalence and incidence of high risk for obstructive sleep apnea in World Trade Center-exposed rescue/recovery workers. Sleep Breath. 2011 Sep;15(3):283-94. doi: 10.1007/s11325-010-0379-7. Epub 2010 Jul 1.
Yeager DE, Magruder KM, Knapp RG, Nicholas JS, Frueh BC Performance characteristics of the posttraumatic stress disorder checklist and SPAN in Veterans Affairs primary care settings. Gen Hosp Psychiatry. 2007 Jul-Aug;29(4):294-301.
Interventional studies are often prospective and are specifically tailored to evaluate direct impacts of treatment or preventive measures on disease.
Observational studies are often retrospective and are used to assess potential causation in exposure-outcome relationships and therefore influence preventive methods.
Expanded access is a means by which manufacturers make investigational new drugs available, under certain circumstances, to treat a patient(s) with a serious disease or condition who cannot participate in a controlled clinical trial.
Clinical trials are conducted in a series of steps, called phases - each phase is designed to answer a separate research question.
Phase 1: Researchers test a new drug or treatment in a small group of people for the first time to evaluate its safety, determine a safe dosage range, and identify side effects.
Phase 2: The drug or treatment is given to a larger group of people to see if it is effective and to further evaluate its safety.
Phase 3: The drug or treatment is given to large groups of people to confirm its effectiveness, monitor side effects, compare it to commonly used treatments, and collect information that will allow the drug or treatment to be used safely.
Phase 4: Studies are done after the drug or treatment has been marketed to gather information on the drug's effect in various populations and any side effects associated with long-term use.
