Rigidity of psyche processes and factors predisposing to schizophrenia
: To evaluate the rigidity of psychic processes (RPP) as a factor predisposing (vulnerability) to schizophrenia and to study interactions between RPP and other susceptibility factors, psychological characteristics and magnetic resonance tomography data have been studied in 26 families with schizophrenia. Correlation, cluster and regression analyses and trait phenotypic variance decomposing into genetic and environmental components for heritability estimation were used. RPP indices in patients with schizophrenia and their relatives differed significantly from those in the control group of healthy subjects without positive family history of schizophrenia. The RPP heritability was estimated as high (58%). In RPP patients, RPP clustered with parameters of attention, memory, dynamic and intellectual activity; in the siblings--with attention, dynamic and intellectual activity and the width of anterior horns of left and right lateral ventricules next to genum, in the parents--with motivation, attention, memory, dynamic and intellectual activity. In the siblings, heritability for parameters of frontal horn lateral ventricules was estimated as high (66%) for the right ventricles and moderate (30%) for the left ones. Both morphological parameters are among morphological predictors for prognosis of negative symptoms in the patients with schizophrenia. The authors regarded RPP as a factor predisposing to schizophrenia.