Processing Speed as an Endophenotypic Marker of Paranoid Schizophrenia

Schizophrenia is associated with basic neurocognitive deficit- ineffective space-time information assessment, leading to ineffective judgment and planning of behaviour. Our study aimed to examine and compare the psychomotor speed and number of errors in patients with paranoid schizophrenia (PS), first-degree relatives (FDR) and healthy controls (HC). One-hundred-eight patients with PS, 58 with FDR and 60 HCs were examined via Trail Making Tests (TMT) A and B. The influence of other additional factors as The Positive and Negative Syndrome Scale (PANSS), demographics and education were additionally assessed for PS. Statistical analysis was done using Excel 2010, Statgraphics 5.0+ and SPSS 20. All results were interpreted at 95% confidential level. PS showed most unsatisfactory performances on TMT A and B, as compared to others (p=0.0001). However, FDR differed from HC only in TMTB performance (p=0.0241). The most significant impact in PS group included ageing, education, PANSS and negative syndromes, and syndromes of disorganization. PS showed a significant decline of psychomotor speed and executive functioning, although FDR had average results in TMTB, compared to PS and HC. The above results determined both detentions as endophenotype markers for PS. Additional risk factors for decline include ageing, low education and high PANSS results.