Neuropsychological correlates of remission in chronic schizophrenia subjects: The role of general and task-specific executive processes

Abstract

BackgroundAlthough cognitive deficits have consistently been characterized as core features of schizophrenia, they have not been incorporated into definitions of remission. Furthermore, just a few studies have examined the relationship between cognitive deficits and symptomatic remission. The main aim of the present study is to evaluate the executive functioning of nonremitted schizophrenia patients.Methods72 remitted and 42 nonremitted schizophrenia patients, and 119 healthy controls were examined. Subjects were tested with a comprehensive battery of cognitive tests, including a measure to assess the general components of executive functioning and individual tasks to tap the three specific executive dimensions assessed in the present study, namely updating, shifting and inhibition.ResultsSchizophrenia subjects performed poorly on general executive functioning and shifting tasks in comparison to healthy controls. Remitted subjects performed better than nonremitted on inhibition and updating tasks. Whereas being a male and showing decreases in updating increase the chances of being in the nonremitted schizophrenia subjects group, increases in shifting and updating enhance the odds of being in the healthy control group.ConclusionThe present findings suggest that executive function deficits are present in chronic schizophrenic patients. In addition, specific executive processes might be associated to symptom remission. Future studies examining prospectively first-episode, drug naive patients diagnosed with schizophrenia may be especially elucidative.

Decreased interhemispheric connectivity and increased cortical excitability in unmedicated schizophrenia: A prefrontal interleaved TMS fMRI study

“…Cognitive dysfunction has been identified in both schizophrenia patients and otherwise asymptomatic first-degree relatives compared to controls [7,8]. Additionally, unlike other schizophrenia symptoms which fluctuate over time, cognitive deficits seem largely stable [9] e although some studies provide evidence for graded remission [10].…”

Component mechanisms of executive function in schizophrenia and their contribution to functional outcomes

“…Neuroimaging data from healthy individuals support the unity/diversity model in that the updating mechanism appears to mainly recruit areas in the lateral prefrontal cortex,12 that switching between mental sets is thought to depend on the medial prefrontal cortex,13 and that inhibition tasks mainly activate the orbitofrontal cortex 14. In schizophrenia, some of these skills present consistent evidence of impairment,15 -17 association with diagnostic gene candidates,18,19 association with peripheral levels of chemokines, brain-derived neurotrophic factor (BDNF) and oxidative markers,20 and potentially available homologous animal models 21…”

Seis factores que afectan el funcionamiento cognitivo en la esquizofrenia. Una revisión sistemática 2016-2021

“…No obstante, en ambas fases parecen prevalecer los déficits neurocognitivos en el funcionamiento ejecutivo con marcado deterioro en la ToM, en relación con la comprensión de las intenciones de los demás a partir de pistas simples, reducida conciencia de los límites cognitivos y de la percepción cognitiva general (Burton, 2016;Popolo et al, 2016). Estas deficiencias pueden estar relacionadas con alteraciones en la plasticidad neuronal cerebral, lo que sugiere que la alteración cognitiva es un síntoma central de la esquizofrenia y que se correlaciona con las alteraciones neuroanatómicas y de conectividad cerebral presentes en la psicopatología (Bora et al, 2016;Rabanea-Souza et al, 2016;Ruiz-Sánchez et al, 2021). Es por ello que resulta poco probable que la medicación contribuya al deterioro de la función cognitiva en la esquizofrenia crónica (Wu et al, 2016).…”