Negative Symptoms and Executive Function in Schizophrenia: Does Their Relationship Change with Illness Duration?

Abstract

Background: Negative symptoms and cognitive dysfunction are of crucial functional and prognostic importance in schizophrenia. However, the nature of the relationship between them and the factors that may influence it have not been well established. Aims: To investigate whether the relationship between negative symptoms and executive function changes according to the duration of illness in schizophrenia. Methods: The Positive and Negative Syndrome Scale was used to assess psychopathology and the Wisconsin Card Sorting Test (WCST) to evaluate executive function in a sample of 200 schizophrenic patients who were classified in 3 groups according to their duration of illness: up to 5 years (short duration group), 6-20 years (intermediate duration group) and over 20 years of illness (long duration group). Results: Medium-sized correlations were found between negative symptoms and WCST performance as assessed by the number of completed categories in all 3 groups. However, differences were found according to the duration of schizophrenia. For patients in the short duration group, negative symptoms correlated with WCST nonperseverative errors, but for those in the long duration group the correlation was with perseverative errors. Conclusion: We found a differential relationship between negative and cognitive symptoms in different stages of schizophrenia. Illness duration should be considered when studying the relationship between negative symptoms and cognition.

Medial frontal gyrus alterations in schizophrenia: Relationship with duration of illness and executive dysfunction

“…This observation is partially in line with previous findings. In a recent study, Bagney et al (2013) reported no differences in the non-PE, PE and CAT scores between three groups of patients with different DoI (i.e., up to 5 years, 6-20 years, and more than 20 years). We can speculate that these differences may be secondary to the different temporal subdivision within the patient groups compared with that in the present study (i.e., 10 years).…”

The relationship between moderate-to-vigorous physical activity and executive function among individuals with schizophrenia: differences by illness duration

“…This null result could be due to the chronicity of schizophrenia, particularly considering that these participants had demonstrated greater cognitive impairment (based on the Symbol Coding task), which is consistent with previous literature. 25,26 Duration of illness appears to be an important factor to be considered further when exploring the relationship between PA (and MVPA in particular) and cognitive function. Data presented as n (%), unless otherwise specified.…”

“…Considering that the relationship between cognitive function and illness duration may not be linear, [24][25][26] and that illness duration is used as an approximation to the stage of illness, 25 the sample was dichotomized on the basis of illness duration using a median split (median = 14. …”

Measuring pathology using the PANSS across diagnoses: Inconsistency of the positive symptom domain across schizophrenia, schizoaffective, and bipolar disorder

“…The relationship between the negative symptom structure and executive functioning may depend on illness duration (Bagney et al, 2013), possibly due to the change in the negative symptoms with illness duration. We assess whether subsets of items provide more stable measurement not across illness phase, but across illness, by testing the invariance of the PANSS within both a full and reduced PANSS.…”