Cognitive disorders in schizophrenia

Currently, there is evidence that schizophrenia is associated with impairment of many cognitive functions (Green M.F. et al., 2004). They are found in healthy relatives of the first degree of kinship, in patients - already in childhood, in the premorbid condition of the disease, most clearly manifested in high-risk states - psychopathological diathesis (Sheinina N.S., Kotsyubinsky A.P., Skorik A.I., Chumachenko A.A., 2008; Sofronov A.G., Spikina A.A., Savelyev A.P., Pashkovsky V.E., 2011). In the prodromal period of schizophrenia, there is an increase in cognitive deficit associated with morphological and functional changes in the brain, which leads to the development of psychosis (Yanushko M.G. et al., 2014; Welham J. et al., 2009), during which cognitive disorders persist (Lesh TA et al., 2011). Patients with endogenous psychosis, already at the first hospitalization, have impaired cognitive functioning, and in patients with schizophrenia they are most pronounced (Reichenberg A. et al., 2009). While in the ICD-10 cognitive impairments are noted only sporadically as diagnostic criteria (for example, speech impoverishment in schizophrenia), the DSM-V emphasizes the clinical importance of cognitive dysfunctions for verifying psychiatric diagnoses (APA, 2013). The possibility of including cognitive impairments in the number of diagnostic signs of schizophrenia was considered, which was rejected due to the lack of sufficient data to differentiate cognitive function in schizophrenia and other disorders. Cognitive deficits, for which effective remedies are currently lacking (Vingerhoets WA et al., 2013), are associated with the problems of social functioning of patients and functional outcome (Sofronov A.G. et al., 2012; Milev P. et al., 2005) ; Prouteau A. et al., 2005; Torrey EF, 2006), prognosis of schizophrenia (Kahn and Keefe, 2013).