Clinical definitions and differencial diagnosis criteria of «Schizotypal personality disorder» is not enough investigated yet, especially how it differs from schizoid personality disorder and continuous sluggish schizophrenia. It is impossible to consider diagnostic indications (that the symptoms of schizophrenia couldn’t be observed before and during actual examination) sufficient to explain the special place of this mental disorder. Some criteria of diagnosis of schizotypal disorders (for example, suspiciousness and paranoid ideas, episodes of quazi- psychotic disorders) are not applicable.

With the aim to define the clinical features of schizotypal personality disorder 58 patients were examined. All patients were characterized by mainly personality disorders.

1. - Schizotypal personality disorder is similar to deficit states, observed at schizophrenia, clinically limited to personality sphere, without the signs of flow of endogenous process and psychotic disorders.

2. - Schizotypal personality disorder on the clinical content reminds schizoid, but insignificant ideatory disorders are rather typical. Dymamic of psychopathy - disposition to decompensation - is never observed.

3. - Schizotypal personality disorder can be diagnosed as latent, prodromal schizophrenia, because the clinical picture of these states is very similar. The special value acquires a dynamic aspect, allowing to find the signs of «flow» and dynamics typical of the endogenous process.

Thus, the main differencial diagnosing criteria of schizotypal personality disorder are the dynamic aspects and changing of clinical features.