The blurring of nosological boundaries across clinical forms of schizophrenia is critical. The aim of the research was to address the relationships between neuropsychological functioning, clinical scales and international diagnosis criteria for a comprehensive diagnosis of schizophrenia.

67 patients diagnosed with schizophrenia according to ICD-10 criteria were included in the current study. The average age of the patients was 33.17 years (SD=9.22). Patients included were not diagnosed with medical or neurological conditions. In clinical assessment PANSS, GAS and CGI tests were used, and also neuropsychological computerized assessment of working memory and implicit learning (WLM, SWM), executive functioning (STDT), time of reaction (SST), discrimination of facial emotional expression (PEAT).

In four forms of schizophrenia (paranoid, catatonic, simplex and non-differentiated), high scores on the negative PANSS scale were revealed, while on the positive PANSS scale, high scores were revealed in two of these forms (paranoid and non-differentiated). Significant correlations were found between delusional-hallucinatory symptoms and deficits in neuropsychological functioning (implicit learning, decision time, perseverance in errors). Significant correlations were found between apathy, social withdrawal, avolition, difficulties in abstract thinking, working memory disorders, attention deficit. Discriminating ability between emotional expressions did not correlate with PANSS scores, however it did correlate with GAS scores.

1. Schizophrenia clinical forms can not be distinguished through PANSS or GAS scores. 2. Neuropsychological assessment appears to be a fine differentiating diagnostic tool between different clinical forms of schizophrenia. 3. Impaired cognitive functioning ads to the dimensional diagnosis of schizophrenia.