Cross-sectional Evaluation of Psychiatric Population With DELPhI- Characterization of Psychiatric Conditions

Psychiatric conditions requiring pharmaceutical treatment include Schizophrenia and other psychotic disorders, Major depressive disorder, Bi-polar disorder, Post Traumatic Stress Disorder, Obsessive Compulsive Disorder and anxiety disorders. To date none of the psychiatric conditions mentioned diagnosis' relies on an imaging or other quantitative technique. Diagnosis and treatment prescription in the psychiatric clinic still relies on subjective reports and physician assessment of symptoms. Trans-cranial magnetic stimulation (TMS) is a noninvasive brain stimulation method that allows to study human cortical function In-vivo. Using TMS for examining human cortical functionality is enhanced by combining TMS with simultaneous registration of electroencephalograph (EEG). EEG provides an opportunity to directly measure the cerebral response to TMS, measuring the cortical TMS Evoked potential (TEP), is used to assess cerebral reactivity across wide areas of neo-cortex. Studies integrating TMS with EEG (TMS-EEG) have shown that TMS produces waves of activity that reverberate throughout the cortex. and that are reproducible and reliable thus providing direct information about cortical excitability and connectivity with excellent time resolution. By evaluating the propagation of evoked activity in different behavioral states and in different tasks, TMS-EEG has been used to causally probe the dynamic effective connectivity of human brain networks.