Moritz S, Kuelz AK, Jacobsen D, Kloss M, Fricke S Severity of subjective cognitive impairment in patients with obsessive-compulsive disorder and depression. J Anxiety Disord. 2006;20(4):427-43. Epub 2005 Jun 1.
Putzke JD, Williams MA, Daniel FJ, Bourge RC, Boll TJ Self-report versus performance based activities of daily living capacity among heart transplanta candidates and their caregivers. Journal of Clinical Psychology in Medical Settings 2000;7:121-32.
Radloff LS The CES-D Scale: A self-report depression scale for resarch in the general population. Applied Psychological Measurement 1077;1:385-401.
Schwartz GE, Davidson RJ, Goleman DJ Patterning of cognitive and somatic processes in the self-regulation of anxiety: effects of meditation versus exercise. Psychosom Med. 1978 Jun;40(4):321-8.
Smith A Symbol Digit Modalitites Test.Los Angeles:Western Psychological Services; 1982.
Tombaugh TN Trail Making Test A and B: normative data stratified by age and education. Arch Clin Neuropsychol. 2004 Mar;19(2):203-14.
Wechsler D The Wechsler Test of Adult Reading. San Antonio, Texas: PsychCorp;2001.
Origins of Cognitive Dysfunction in Postural Tachycardia Syndrome (POTS)
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.
