RESUMO
Impairments in cognitive functions are one of the main features of schizophrenia. A variety of factors can influence the extent of cognitive deficits. In our study, we examined the severity of cognitive deficits at different stages of the disease and the relationship between psychopathological symptoms and cognitive functions. We recruited 32 patients with first-episode psychosis (FEP), 70 with chronic schizophrenia (CS), and 39 healthy controls (HC). Psychopathological symptoms were evaluated with the Positive and Negative Syndrome Scale (PANSS) and cognitive functions were measured with the MATRICS Cognitive Consensus Battery (MCCB). Cognitive deficits were present in both FEP and CS participants. CS individuals had lower overall scores and poorer working memory; however, clinical variables appeared to play a significant role in these scores. In FEP, disorganization correlated negatively with verbal and visual learning and memory, social cognition, and overall score; negative symptoms negatively correlated with social cognition. In CS participants, disorganization correlated negatively with speed of processing, reasoning, problem solving, and overall score; negative symptoms were negatively correlated with speed of processing, visual learning, memory, and overall score; positive symptoms were negatively correlated with reasoning and problem solving. Our findings indicate that psychopathological symptoms have a significant impact on cognitive functions in FEP and CS patients.
RESUMO
There is a paucity of reports examining the relationship between the integrity of the corpus callosum (CC) and different aspects of cognitive functioning in patients with first-episode (FES) and chronic schizophrenia (CS) simultaneously; furthermore, what results exist are inconclusive. We used diffusion tensor imaging tractography to investigate differences in integrity in five regions of the CC between FES, CS, and healthy controls (HC). Additionally, we analyzed correlations between these regions' integrity and working memory, planning, and speed of processing. Eighteen patients with FES, 55 patients with CS, and 30 HC took part in the study. We assessed cognitive functions with four tasks from Measurement and Treatment Research to Improve Cognition in Schizophrenia. Patients with CS showed lower fractional anisotropy (FA) in Region 5 (statistical trend) and higher mean diffusivity (MD) in Regions 4 and 5 than HC, and patients with FES had higher MD in Region 3 (statistical trend) than HC. Both clinical groups performed worse on working memory and speed of processing tasks than HC, and patients with CS scored worse than HC on independent planning, and worse than FES and HC on dependent planning. Moreover, in patients with CS, MD in Region 3 was correlated with verbal working memory. Our results suggest that patients with FES and CS are characterized by impaired integrity of the middle and posterior CC, respectively. We confirmed that both clinical groups have cognitive impairments. Moreover, the integrity of the middle CC may influence planning in patients with CS.
