Aim:
The aim: of this research was to study the psychopathological mechanisms of the development of the prodromal stage of psychosis in order to identify risk factors for the formation of psychosis.

Material and methods:
Materials and methods: In this research 137 patients with newly diagnosed psychosis were examined: 65 patients with a diagnosis of paranoid schizophrenia; 72 patients - with a diagnosis of acute polymorphic psychotic disorder .

Results:
According to the analysis of symptoms using the PANSS, the absence of signs of an anxious state, conceptual disorganization of thinking, emotional withdrowal are reliable signs of PPP in PS, and unusual thought content, absence of signs of stereotyped thinking, tension, anxiety, and hallucinations are reliable signs of PPP in APPD. According to the analysis of symptoms using the SOPS, unusual thought content/delusional ideas, bizarre thinking, social anhedonia, suspiciousness/persecutory ideas, decrease in expressiveness of emotions are reliable signs of PPP in PS, and bizarre thinking, impaired tolerance to normal stress, sleep disturbance, perceptual abnormalities/hallucinations, trouble with focus and attention are reliable signs of PPP in APPD.

Conclusions:
: In the process of studying the clinical-psychopathological and pathopsychological aspects of the development of the PPP, a number of risk factors for the formation of psychosis were identified. We found that he most important diagnostic signs of PPP in PS patients are: stereotyped thinking, social isolation, disorganizational thinking disorders, passive-apathetic social detachment, suspiciousness. The most informative prodromal symptoms of HP in PS patients are: conceptual disorganization of thinking, bizzare thinking, social isolation, suspiciousness/persecutory ideas, reduced expression of emotions.