Cognition, Function, and Disability in Patients with Schizophrenia: A Review of Longitudinal Studies

Abstract

This paper aims to review longitudinal studies assessing the impact of cognition on function in patients with schizophrenia. PubMed and Scholars Portal were searched using search terms related to schizophrenia, cognition, function, and longitudinal studies. Some functional abilities have been studied more than others. Some studies suggest that the impact of cognition on function depends on the severity of baseline cognitive deficits. Other studies suggest that the impact of cognition on function depend on what phase of the illness the patient is in or what stage in that particular function the patient is involved in. Finally, few studies assessed interactions between cognition and other aspects of schizophrenia in predicting function, such as functional capacity, insight, motivation, and negative symptoms. More longitudinal and comprehensive studies are needed. A focus on community living is of high public significance as patients with schizophrenia continue to grow old. Future studies should also focus on the longitudinal interactions between cognition and other dimensions of schizophrenia as well as on the biological factors that underlie these interactions. W W W Cognition, fonction et incapacité chez des patients souffrant de schizophrénie : une revue des études longitudinalesCet article vise à examiner les études longitudinales évaluant l'effet de la cognition sur la fonction des patients souffrant de schizophrénie. Des recherches ont été effectuées dans PubMed et Scholars Portal à l'aide de mots clés liés à la schizophrénie, la cognition, la fonction, et les études longitudinales. Certaines capacités fonctionnelles ont été étudiées plus que d'autres. Des études suggèrent que l'effet de la cognition sur la fonction dépend de la gravité des déficits cognitifs au départ. D'autres études font valoir que l'effet de la cognition sur la fonction dépend de la phase de la maladie ou du stade de cette fonction où se situe le patient. Enfin, peu d'études ont évalué les interactions entre cognition et autres aspects de la schizophrénie pour prédire la fonction, comme la capacité fonctionnelle, l'intuition, la motivation, et les symptômes négatifs. Il faut plus d'études longitudinales et exhaustives. Mettre l'accent sur la vie dans la communauté est d'une grande importance publique car les patients souffrant de schizophrénie continuent de vieillir. Les futures études devraient aussi se pencher sur les interactions longitudinales entre la cognition et d'autres dimensions de la schizophrénie, ainsi que sur les facteurs biologiques qui sous-tendent ces interactions.S chizophrenia affects more than 24 million adults, worldwide, and about a quarter of a million in Canada.

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“…Individuals with schizophrenia show cognitive decline at all stages of the disease (Rajji et al 2014). This cognitive decline can be easily observed by testing for changes in the episodic memory response of people with schizophrenia (Schaefer et al 2013), (Barch and Sheffield 2014).…”

Paliperidone Protects SH-SY5Y Cells Against MK-801-Induced Neuronal Damage Through Inhibition of Ca2+ Influx and Regulation of SIRT1/miR-134 Signal Pathway

“…Schizophrenia is a serious psychotic disease which affects about 1 % of the world population [1]. Schizophrenia patients suffer from positive symptom (delusions, auditory hallucinations, and thought disorder) and negative symptom (blunted affect and emotion, alogia, anhedonia, and avolition) accompanying with deficit of cognition and these symptoms become apparently at late adolescent time or in early adulthood [2].…”

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Working Memory Training in Schizophrenia and Healthy Populations

“…Both auditory and visual working memory are important for interpersonal day-to-day functioning of individuals with schizophrenia, including in social, occupational, educational, and community settings [15]. For example, well-functioning auditory working memory processes likely allow an individual to follow and respond to conversations and instructions, while visually working memory may be important for finding a job site or navigating an office environment, and manually manipulating objects to perform a task [15,39,40]. Given the known cognitive deficits in schizophrenia, and the potential implications of poor working memory in schizophrenia, it is surprising that more research has not focused specifically on working memory enhancement, whether specific to auditory or visual representations, or other representations (e.g., speech, motor, tactile, mood).…”

“…Compromised working memory has negative consequences for overall functioning in schizophrenia. For example, working memory deficits predict poor community functioning, decreased self-care and health maintenance activities, compromised vocational and social functioning, poor overall quality of life, and overall disability in schizophrenia [15]. Hence, improving working memory in schizophrenia could have wide-spread implications on day-to-day functioning for patients.…”