Cho RY, Konecky RO, Carter CS Impairments in frontal cortical gamma synchrony and cognitive control in schizophrenia. Proc Natl Acad Sci U S A. 2006 Dec 26;103(52):19878-83. Epub 2006 Dec 14.
Green MF What are the functional consequences of neurocognitive deficits in schizophrenia? Am J Psychiatry. 1996 Mar;153(3):321-30. Review.
Lisman J, Buzsáki G A neural coding scheme formed by the combined function of gamma and theta oscillations. Schizophr Bull. 2008 Sep;34(5):974-80. doi: 10.1093/schbul/sbn060. Epub 2008 Jun 16. Review.
Stagg CJ, Nitsche MA Physiological basis of transcranial direct current stimulation. Neuroscientist. 2011 Feb;17(1):37-53. doi: 10.1177/1073858410386614. Review.
Uhlhaas PJ, Singer W Abnormal neural oscillations and synchrony in schizophrenia. Nat Rev Neurosci. 2010 Feb;11(2):100-13. doi: 10.1038/nrn2774. Review.
Volk DW, Lewis DA Prefrontal cortical circuits in schizophrenia. Curr Top Behav Neurosci. 2010;4:485-508. Review.
Non-Invasive Direct Current Stimulation for Cognition in Schizophrenia
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.