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Background: In the last decade, the kynurenine pathway (KP) has gained attention in the pathogenesis of cognitive impairment in schizophrenia being at the croassroad between neuroinflammation and glutamatergic and cholinergic neurotransmission. However, clinical findings are scarse and conflicting, and the specific contributions of these two systems to the neurobiology of cognitive symptoms are far from being elucidated. Furthermore, little is known about the molecular underpinnings of non-pharmacological interventions for cognitive improvement, including rehabilitation strategies. Methods: The current study examined 72 patients with schizophrenia, divided in two clusters depending on the severity of the cognitive impairment, with the aim to evaluate the impact of inflammatory biomarkers and KP metabolites depending on cognitive functioning. Moreover, we studied their possible link to the cognitive outcome in relation to sessions of cognitive remediation therapy (CRT) and aerobic exercise (AE) in a longitudinal arm of 42 patients. Results: Neuroinflammation appeared to exert a more pronounced influence on cognition in patients exhibiting a higher cognitive functioning, contrasting with the activation of the KP, which had a greater impact on individuals with a lower cognitive profile. Cognitive improvements after the treatments were negatively predicted by levels of TNF-α and positively predicted by the 3-hydroxykynurenine (3−HK)/kynurenine (KYN) ratio, an index of the kynurenine-3-monooxygenase (KMO) enzyme activity. Conclusion: Overall, these findings add novel evidence on the biological underpinnings of cognitive impairment in schizophrenia pointing at a differential role of neuroinflammation and KP metabolites in inducing cognitive deficits depending on the cognitive reserve and predicting outcomes after rehabilitation.

Cognitive Remediation Therapy (CRT) represents the gold standard treatment for cognitive impairment in schizophrenia, but the permanence of its effects over time have been poorly investigated. Our study aims to evaluate long lasting cognitive and functional effects of CRT together with standard rehabilitation interventions (SRT) in a group of patients diagnosed with schizophrenia, 10 years after the end of the treatment. Forty patients, previously included in a 5-year follow-up study evaluating the effects of CRT combined with SRT, were revalued 10 years after the complete of the intervention. Results revealed that cognitive and functional improvements of combined CRT/SRT interventions are still preserved 10 years after the end of the treatments, with the only exception of psychomotor speed and coordination cognitive subdomain. Moreover, investigating persistence of the influence of SRT, patients that underwent a shorter SRT following CRT (six months vs one year) showed worsened processing speed abilities.This is the first study confirming that cognitive and functional improvements of joint CRT/SRT interventions are still conserved 10 years after the end of the treatments. Preliminary datas suggest that a longer SRT following CRT may lead to significant benefits, in terms of cognitive gains, in patients affected by schizophrenia.

Low mobility and poor physical health, especially metabolic syndrome, are frequently reported in patients with schizophrenia and tend to increase with age. Recent evidence suggests that metabolic syndrome may affect cognition and quality of life, while the role functional mobility is still less addressed and their interplay needs to be further explored. This study aims to analyze the effects of functional mobility on cognitive performance, symptoms and quality of life, taking into account age and also modeling it relationship with metabolic syndrome in a sample of 103 adults with chronic schizophrenia.Data were analyzed by means of Pearson's correlations, forward stepwise regressions and mediation models.Results showed that poorer functional mobility is associated with metabolic syndrome and related to more severe negative symptoms, worse cognitive abilities and more disrupted quality of life. Moreover, functional mobility proved to be a significant predictor of cognitive abilities and quality of life, even when other influencing factors were taken into account and independently of age. Finally, analyses showed that functional mobility mediates the effect of metabolic syndrome on both cognition and quality of life.Taken together, these results suggest that functional mobility and metabolic syndrome may represent relevant aspects that further contribute to the evolution of cognitive deficits through all stages of the disease, with also impact on quality of life. In this perspective, the assessment of functional mobility, a non-invasive and quickly performed test may be worth to be implemented in clinical practice, with important implications for treatment and monitoring.

Obsessive-compulsive symptoms (OCS) are frequently reported in clozapine-treated schizophrenia. Studies on the effects of OCS on cognitive abilities and quality of life (QoL) yielded contrasting results, ranging from benefits to adverse effects. We investigated the interactive effects of OCS and cognitive functioning on different aspects of QoL in clozapine-treated patients. 54 patients with schizophrenia underwent a neurocognitive, functional and psychopathological battery. Using moderation models, we examined the interplay between OCS and cognitive abilities on different QoL domains. We found several main effects and interactions between I.Q. and OCS on global QoL, as well as specific effects on psychological and environmental domains. Mild OCS have beneficial effects on QoL, but, as OCS become more severe in patients with more preserved cognitive abilities, the QoL drops steeply. Findings highlight the complex interplay between OCS and cognitive functioning, whose effects on QoL appear to depend on patients’ OCS severity and cognitive profile, as well as on the functional domain addressed. Our data may help to reconcile the seemingly contrasting results from previous studies, and shed a new light on the importance of evaluating OCS in schizophrenia, thus establishing specific interventions that can lead to consequent effects on social well-being and QoL.