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Cognitive impairments are considered core features of schizophrenia and are recognized as the most important predictors of functional outcome and quality of life. A better study of the mechanisms underlying the cognition is of extreme relevance. Literature has shown that several genetic and environmental factors affect cognitive performance. In particular, the interaction between Catechol-O-Methyltransferase (COMT) gene and cannabis use has gained increasing attention in the past years. Based on these premises, the present study, aimed to analyze the interplay between cannabis use and COMT polymorphism on cognitive performance in a sample of 135 patients with chronic schizophrenia. Patients were assessed for neurocognitive measures with a broad battery, genotyped for COMT Val158Met polymorphism from peripheral blood sample, and evaluated with a semi-structured interview in order to establish the history of cannabis abuse. Results showed a significant interaction effect between COMT polymorphism and cannabis use on verbal fluency and speed of processing. The analysis revealed significant differences between subjects COMT Val/Val homozygous and Met carriers with history of cannabis use, with a better performance on both tasks among the Met carriers group. These data are in line with literature on healthy subjects that suggests a more detrimental effect of cannabis among subjects with Val/Val genotype. In conclusions, results highlight the need to better disentangle the biological pathways in which cannabis use and COMT are converging, as possible treatment targets, as well as the importance to assess these factors in clinical to optimize individualized interventions., (Copyright © 2019 Elsevier Inc. All rights reserved.)

The role of genetics in cognitive remediation therapies in schizophrenia has not been completely understood yet. Different genes involved in neurotrophic, dopaminergic and serotonin systems have reported to influence cognitive functioning in schizophrenia. These genetic factors could also be contributing to the variability in responsiveness to cognitive treatments. No comprehensive synthesis of the literature of the role of genetics in the context of cognitive remediation has been conducted until now. We aimed to systematically review the published works through three electronic database searches: PubMed, Scopus, and the Cochrane Library. Eligible studies revealed a rising interest in the field although the number of published studies was rather small (n = 10). Eventually, promising results showing a relationship between some phenotypic variations based on different polymorphisms and different levels of responsivity to cognitive remediation therapies have been described although results are still inconclusive. In case those findings will be replicated, they could be guiding future research and informing clinical decision-making in the next future., (© 2019 The Authors.)

The relationship between neurocognition and functioning among patients with schizophrenia is well documented. However, integrating neuropsychological, clinical and psychopathological data to better investigate functional outcome still constitutes a challenge. Artificial neural network-based modeling might help to better capture clinical heterogeneity by analyzing the non-linear relationships among multiple variables. Two hundred and fourteen clinically stabilized patients with schizophrenia were recruited and assessed for neurocognition, psychopathology and functioning. Artificial neural network analyses were conducted to yield significant predictors of functional outcome among clinical and cognitive variables and to build distinct functional Profiles, each characterized by a different medley of cognitive and clinical features. Twenty-two key predictors of daily functioning emerged, encompassing neurocognitive and clinical domains, with major roles for processing speed and attention. Four Profiles were constructed based on specific levels of functioning, each characterized by a distinct distribution of key clinical and neurocognitve measures. This study highlights the importance of a more in-depth investigation of cognitive and clinical heterogeneity. A better understanding of the building blocks of these Profiles would lead to more individualized rehabilitation treatments., (Copyright © 2018. Published by Elsevier B.V.)

Cognitive deficits represent core features of schizophrenia, affecting quality of life and functioning. The excitatory amino acid transporter 2 (EAAT2) is responsible for the majority of glutamate reuptake and its activity is crucial for glutamatergic neurotransmission, prevention of excitotoxic damage and cerebral metabolism. Different studies reported that EAAT2 rs4354668 (-181 T/G) influences cognitive functions and brain structures in patients with schizophrenia. Specifically, the G allele, linked to lower EAAT2 expression, was associated with impaired prefrontal cognitive performance and reduced grey matter volumes. Cognitive remediation therapy (CRT) is one of the best available tool to treat cognitive deficits in schizophrenia, able to induce a neuroplastic modulation of cognitive functions. The present study aims to investigate the effects of rs4354668 on CRT outcome, also considering possible genotype interaction with antipsychotic (AP) treatment, since EAAT2 expression is negatively influenced by clozapine. We examined rs4354668 in 88 clinically stabilized patients with schizophrenia, treated with CRT and assessed at enrolment, at the end of CRT and after 3 months. We observed greater working memory improvements among patients carrying the T/T genotype, regardless of AP treatment. Moreover, we reported a significant interaction between pharmacological treatment and rs4354668 on executive functions, with greater improvements among T/T patients treated with APs other than clozapine. These observations suggest that impaired EAAT2 expression may attenuate CRT outcome. Moreover, our results indicate the possibility that rs4354668 could also differentially influence the response to CRT depending on the AP treatment., (Copyright © 2018 Elsevier B.V. All rights reserved.)

Anxiety is among the least studied features of schizophrenia, despite evidence of its significant impact on disease outcome. This work aims to investigate the anxiety construct in a sample of outpatients with schizophrenia, exploring the interplay of clinical, neurocognitive and social cognitive domains, as well as adverse childhood experiences and their relative contribute in determining anxiety. A forward stepwise regression model was performed on a sample of 68 outpatients with schizophrenia, to examine the predictive effect of different variables on anxiety. Predictors have been selected based on previous literature and include psychopathological, neurocognitive and social cognitive measures, as well as premorbid environmental factors. The analysis showed a significant contribution of childhood adverse experiences, followed by personal distress, while no significant effect was found for symptom's severity, nor global cognitive efficiency. The results show that anxiety is mainly determined by early environmental factors, as well as by socio-cognitive dimensions, such as personal distress. Data also suggest that anxiety can be considered as an independent construct, rather than as a mere epiphenomenon of the illness. The study has clinical implications as it highlights the importance of implementing both standardized assessments and group interventions specifically targeting anxiety in schizophrenia., (Copyright © 2018. Published by Elsevier B.V.)

Cognitive remediation, often used in combination with standard rehabilitation programs, represents the best available tool to treat cognitive impairments in patients with schizophrenia. However, there are still open questions about durability of effects and generalization of cognitive improvements to functional outcome. This study aims to investigate the persistence of both cognitive and functional effects of combined cognitive remediation plus standard rehabilitation interventions, 5years after completion of the intervention, also comparing different durations of the standard rehabilitation. Sixty patients diagnosed with schizophrenia and previously treated with a 6months intervention, consisting of standard rehabilitation plus 3-months of cognitive remediation, either followed by another year of standard rehabilitation or routine psychiatric treatment, were reassessed with neuropsychological and functional measures 5years after the intervention. Results show that cognitive abilities remained stable after 5years in both groups, while functional performance significantly decreased in patients treated with the 6months intervention only. Data thus suggest that cognitive effects persist even after 5years, while a longer standard rehabilitation following the cognitive remediation program may be needed to achieve a stable functional gain., (Copyright © 2017 Elsevier B.V. All rights reserved.)

Aim: Recovery, or functional remission, represents the ultimate treatment goal in schizophrenia. Despite its importance, a standardized definition of remission is still lacking, thus reported rates significantly vary across studies. Moreover, the effects of rehabilitative interventions on recovery have not been thoroughly investigated. This study aimed to evaluate recovery in a sample of patients with chronic schizophrenia engaged in rehabilitation programs and to explore contributing factors, with a focus on sociocognitive rehabilitative interventions., Methods: Data from 104 patients with schizophrenia treated either with a standard rehabilitation program, including cognitive remediation (n = 46), or the latter plus a specific sociocognitive intervention (n = 58), and assessed for psychopathology, cognition, social cognition, and Quality of Life Scale, were retrospectively analyzed for this study., Results: Recovery, evaluated with the Quality of Life Scale, was achieved by 56.76% of patients in our sample. While no effects were observed for clinical, cognitive, or sociocognitive variables, participation in the sociocognitive rehabilitative interventions was positively associated with recovery., Conclusion: Our results indicate that high rates of recovery can be achieved in patients treated with psychosocial interventions and suggest that rehabilitative programs targeting social cognition may further facilitate the process of recovery. If confirmed, these results may have relevant implications for daily clinical practice and service provision, allowing clinicians to develop and optimize specific rehabilitation programs in order to promote recovery., (© 2017 The Authors. Psychiatry and Clinical Neurosciences © 2017 Japanese Society of Psychiatry and Neurology.)

Impairment in daily functioning still represents a major treatment issue in schizophrenia and a more in-depth knowledge of underlying constructs is crucial for interventions to translate into better outcomes. This study aims to model factors influencing both functional capacity and real-life behaviour in a sample of outpatients with chronic schizophrenia, through a comprehensive assessment including evaluations of psychopathology, cognitive and social cognitive abilities, premorbid adjustment, family environment and early childhood experiences. No significant correlation was observed between functional capacity and real-life behaviour. Functional capacity was significantly predicted by IQ, while real-life behaviour was significantly predicted by empathy, affect recognition and symptoms. Functional capacity seems mainly related to neurocognition, whereas real-life behaviour appears more complex, requiring the integration of different factors including symptoms, with a major role of empathy. Results thus support a divergence between the two constructs of functioning and their underlying components and highlight the need to target both dimensions through individualized sequential rehabilitation programs in order to optimize functional outcome., (Copyright © 2017 Elsevier Ireland Ltd. All rights reserved.)

Background: Impairments in specific aspects of pragmatic competence, supporting the use of language in context, are largely documented in schizophrenia and might represent an indicator of poor outcome. Yet pragmatics is rarely included in clinical settings. This paper aims to promote a clinical consideration of pragmatics as a target of assessment and intervention. We investigated the frequency of the pragmatic deficit, its cognitive substrates, and the relation with quality of life., Methods: Pragmatic abilities were compared in a sample of patients with schizophrenia and healthy controls based on a comprehensive pragmatic test (APACS). We assessed also for psychopathology, cognition, social cognition, and quality of life. We explored the co-occurrence of deficits in different domains, and we used multiple regressions to investigate the effect of cognition and social cognition on pragmatics, and of pragmatics on quality of life., Results: Pragmatic abilities, especially comprehending discourse and non-literal meanings, were compromised in schizophrenia, with 77% of patients falling below cutoff. Pragmatic deficit co-occurred with cognitive or socio-cognitive deficits in approximately 30% of cases. Multiple regression analysis confirmed the interplay of cognition and social cognition in pragmatic behavior. Quality of life was predicted by symptoms and by pragmatic abilities., Conclusions: The high frequency of impairment suggests that the pragmatic deficit is a core feature of schizophrenia, associated with quality of life. Cognitive and socio-cognitive abilities might represent necessary though not sufficient building blocks for the acquisition of pragmatic abilities throughout development. Therefore, a more precise incorporation of pragmatics in the description of the pathology is of high clinical and translational relevance., (Copyright © 2016 Elsevier Inc. All rights reserved.)

The biological bases of cognitive impairment in schizophrenia are poorly understood and may lie in insults in neurodevelopment, leading to alterations in critical structures. Synapses proteins are claimed to have etiopathogenic roles and more direct effects on core cognitive functions. Adducins family proteins seem of great interest, as they are fundamental constituents of synapses, involved in actin cytoskeleton assembly-disassembly, responsible of synaptic plasticity. ADD2 is more prominently expressed in brain tissues and influences memory and learning, commonly impaired in schizophrenia. In the present study we tested 342 patients with schizophrenia for three common adducins genetic variants, ADD1 rs4961, ADD2 rs4984 and ADD3 rs3731566, reported to have significant effects on circulatory system in humans. Neuropsychological measures were evaluated with the Brief Assessment of Cognition in Schizophrenia (BACS), a broad battery evaluating core cognitive domains. The analysis showed significant effects of ADD2 genotype on almost every cognitive domain. Moreover, significant interactions between ADD1 and ADD3 were also observed on some BACS subtests, namely Symbol Coding and Verbal Memory. Our findings suggest that adducins are involved in cognitive impairment in schizophrenia. This effect may result both from a direct mechanism affecting synaptic building and plasticity and indirectly as a consequence of vascular insults., (Copyright © 2015 Elsevier Masson SAS. All rights reserved.)

One of the major challenges in the study of language in schizophrenia is to identify specific levels of the linguistic structure that might be selectively impaired. While historically a main semantic deficit has been widely claimed, results are mixed, with also evidence of syntactic impairment. This might be due to heterogeneity in materials and paradigms across studies, which often do not allow to tap into single linguistic components. Moreover, the interaction between linguistic and neurocognitive deficits is still unclear. In this study, we concentrated on syntactic and semantic knowledge. We employed an anomaly detection task including short and long sentences with either syntactic errors violating the principles of Universal Grammar, or a novel form of semantic errors, resulting from a contradiction in the computation of the whole sentence meaning. Fifty-eight patients with diagnosis of schizophrenia were compared to 30 healthy subjects. Results showed that, in patients, only the ability to identify syntactic anomaly, both in short and long sentences, was impaired. This result cannot be explained by working memory abilities or psychopathological features. These findings suggest the presence of an impairment of syntactic knowledge in schizophrenia, at least partially independent of the cognitive and psychopathological profile. On the contrary, we cannot conclude that there is a semantic impairment, at least in terms of compositional semantics abilities., (Copyright © 2015 Elsevier Ltd. All rights reserved.)

Catechol-O-methyltransferase (COMT) gene, a key regulator of prefrontal cortex (PFC) dopamine (DA) availability, has been extensively studied in relation to cognitive domains, mainly executive functions, that are impaired in schizophrenia, but results are still controversial. Since recent studies in patients affected by neurodegenerative and psychiatric disorders suggested a role of saitohin (STH) gene as a concurring factor in hypofrontality, we hypothesize that STH and COMT polymorphisms could have an additive effect on cognition in schizophrenia. Three forty three clinically stabilized patients with schizophrenia were assessed with a broad neuropsychological battery including the Brief Assessment of Cognition in Schizophrenia, the Wisconsin Card Sorting Test and the Continuous Performance Test and were genotyped for COMT Val108/158Met and STH Q7R polymorphisms. We observed the effects of COMT on speed of processing and executive functions, as well as a significant effect of STH on executive functions performances. Moreover, a significant interaction between COMT and STH polymorphisms was found on executive functions, with COMT Val/Val and STH R carriers performing worse. Our results showed a significant interaction effect of COMT and STH polymorphisms on cognitive performances, strengthening the involvement of STH in cognitive impairments, especially in the domains commonly impaired in schizophrenia.

Aim: Clozapine is still considered the gold standard for treatment-resistant schizophrenia patients; however, up to 40% of patients do not respond adequately. Identifying potential predictors of clinical response to this last-line antipsychotic could represent an important goal for treatment. Among these, functional polymorphisms involved in dopamine system modulation, known to be disrupted in schizophrenia, may play a role. We examined the COMT Val158Met polymorphism, which plays a key role in dopamine regulation at the prefrontal level, and the 5-HT1A-R -1019 C/G polymorphism, a target of clozapine activity involved in the interaction between the serotonin and dopamine systems., Materials & Methods: 107 neuroleptic-refractory, biologically unrelated Italian patients (70 males and 37 females) with a DSM-IV diagnosis of schizophrenia who were being treated with clozapine were recruited. Psychopathology was assessed by the Positive and Negative Symptoms Scale (PANSS) at the beginning of treatment, and at weeks 8 and 12. Genomic DNA was extracted from venous blood samples. COMT rs4680 (Val158Met) and 5-HT1A-R rs6295 (-1019 C/G) polymorphisms were analyzed by PCR-based restriction fragment length and direct sequencing, respectively., Results: We found a significant effect of COMT and 5-HT1A-R on the PANSS Negative Subscale variation, with greater improvement among COMT Val/Val and 5-HT1A-R G/G subjects., Conclusion: The findings support the hypothesis that COMT rs4680 and 5-HT1A-R rs6295 polymorphisms could influence the negative symptom response to clozapine, probably through modulation of the dopaminergic system.

Criteria developed by the Remission in Schizophrenia Working Group (RSWG), based upon 8 core symptoms of PANSS, are generally used for evaluation of Remission. However, some concerns have arisen as regard to the ability of the RSWG criteria to detect truly remitted cases. This study aims to compare the severity criteria of remission defined by the RSWG (RSWG-cr) with more restrictive criteria, based upon the use of PANSS factor model., Methods: 112 chronic psychotic outpatients were examined. Symptomatic remission according to RSWGcr was compared with remission according to criteria based on the 20-items of PANSS considered in the consensus five factor model (PANSS-FCTcr), in relation to functional and neurocognitive outcomes., Results: Data from the study demonstrated the superiority of PANSS-FCTcr in identifying patients with higher functional and cognitive outcomes., Conclusion: PANSS-FCTcr seems to be suitable for use in both common clinical practice and research setting, being associated with improved identification of truly remitted patients.

Cognitive remediation is the best available tool to treat cognitive deficits in schizophrenia and has evidence of biological validity; however results are still heterogeneous and significant predictors are lacking. Previous studies showed that cognitive remediation is able to induce changes in PFC function and dopaminergic transmission and thus the study of possible sources of variability at these levels (i.e. antipsychotic treatments and genetic variability) might help to gain a deeper understanding of neurobiological correlates and translate into optimization and personalization of interventions. In the present study, we analyzed the interaction between pharmacological treatment (clozapine vs typical/atypical D2 blockers) and COMT rs4680 polymorphism on cognitive changes after cognitive remediation therapy, in a sample of 98 clinically stabilized patients with schizophrenia. The General Linear Model showed a significant interaction of pharmacological treatment and COMT polymorphism on the improvement in "Symbol Coding" subtest, a global measure of speed of processing. Post-hoc analysis revealed a significant difference between COMT genotypes, when treated with D2 blockers, with worse results among Val/Val patients. These preliminary results suggest that genetic variability, influencing prefrontal dopamine, might affect individual capacity to improve with different patterns, depending on antipsychotic treatment., (Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.)

Aim: To evaluate the effect of functional polymorphisms (rs4354668 and rs2731880) of the excitatory amino acid transporters (EAAT1 and 2) on the cognitive dysfunction that characterizes schizophrenia., Materials & Methods: One hundred and ninety two subjects diagnosed with schizophrenia were assessed with Brief Assessment of Cognition in Schizophrenia, Wisconsin Card Sorting Test, Continuous Performance Test and N-back test and genotyped for rs4354668 and rs2731880., Results: ANOVA showed a significant difference among both EAAT1 and EAAT2 genotype groups on different cognitive measures. Worse performances were observed among carriers of the genotypes associated with lower EAAT expression., Conclusion: RESULTS suggest that impaired activity and EAAT expression could influence cognitive performances in schizophrenia, thus representing a target of interest for development of pharmacological strategies aimed to improve cognition.

Background: The catechol-O-methyltransferase (COMT) Val(108/158)Met polymorphism (rs4680) influences enzyme activity with valine (Val) allele associated with higher enzymatic activity. Several studies suggest that factors influencing dopaminergic transmission could control response to stressful situations. Empathy is an essential element of human behavior, requires the ability to adopt another person's perspective, and has been found to be dysfunctional in schizophrenia., Methods: Twenty-eight schizophrenic patients underwent functional magnetic resonance imaging performing an empathy task. Perceived empathy has been evaluated with the Interpersonal Reactivity Index., Results: An effect of COMT on perceived distress subscale has been shown, with methionine (Met)/Met subjects reporting lower rates of stress compared with Val/Val. Moreover, imaging results showed an effect of genotype on empathy processing in the anterior cingulate with Val/Val subjects showing the lowest activation., Discussion: This is the first study of the effect of rs4680 on interpersonal distress and neural correlates of empathy in schizophrenia. We found a decrease in neural responses in areas that ensure a cognitive control of emotion that is paralleled by perceived distress in interpersonal situation; this functional pattern seems to be influenced by rs4680 COMT polymorphism., (Copyright © 2013 Elsevier Inc. All rights reserved.)

Previous studies documented a bias against disconfirmatory evidence (BADE) in patients affected by schizophrenia spectrum disorders, with some discrepant findings on its relationship with delusions. In order to further investigate the patterns of evidence integration in schizophrenia and delusion, we recruited 40 deluded and non-deluded patients with schizophrenia and 40 healthy control subjects. Participants were administered the BADE test, which consisted of 30 delusion-neutral scenarios, each one progressively described by three subsequent disambiguating statements and providing four types of interpretation to rate for plausibility; at every additional evidence presentation, participants were asked to adjust their ratings. In contrast to previous works, patients displayed both a BADE and a bias against confirmatory evidence (BACE) relative to healthy subjects, as they reduced plausibility ratings on incorrect interpretations and increased plausibility ratings on correct interpretation significantly less over trial progress. Moreover, BACE and BADE measures showed to discriminate differentially control from schizophrenia participants and delusional from non-delusional patients., (Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.)

Saitohin (STH) is an intronless gene nested within the human tau gene, which contains a single nucleotide polymorphism (A/G), suggested to be involved in the physiopathology and clinical course of several neurodegenerative and neuropsychiatric diseases. Recently, an association between this polymorphism and frontal hypoperfusion and clinical prognosis in frontotemporal dementia was reported. The present study sought to evaluate the possible role of the STH polymorphism as a concurring factor of cognitive decline in schizophrenia, a disease sharing both early psychotic manifestations, a core deficit of executive functions and hypofrontality with frontotemporal lobe dementia. 220 clinically stabilized patients with schizophrenia were assessed with the Wisconsin Card Sorting Test (WCST) for evaluation of executive functions and compared for STH allele frequency with 48 patients affected by frontotemporal dementia and 47 healthy subjects. There was no significant difference in allelic distribution between the healthy controls and all other groups, while we observed a significantly greater frequency of G allele among both patients with frontotemporal dementia (p = 0.037) and schizophrenia patients with poor performances of WCST (p = 0.044), compared to schizophrenia patients with best WCST performances. Among the patients with schizophrenia, stratified for age and gender, the STH polymorphism resulted in a significant predictor of WCST performance (p = 0.007). These results suggest a possible contribution of STH gene products on the heterogeneity of core frontal executive functions deterioration, probably through complex interactions with mechanism involved in neurodevelopment and neurodegeneration.

Impairments in social cognition are critical predictors of social functioning in patients with schizophrenia. Emotion processing (EP) and theory of mind (ToM) are hypothesized to influence real-world behavior more directly than basic cognition and represent important targets of intervention. The use of video scenes depicting human interactions could constitute an appropriate tool to enhance understanding of the characters' behavior and stimulate inferences on mental states. The aim of our pilot study was to evaluate longitudinally, with a controlled trial, the feasibility and the efficacy of a single-paradigm emotion recognition and ToM training designed for outpatients affected by schizophrenia, with the goal to create an ecological treatment, overcoming artificial laboratory biases, by the use of specific videotaped material. Fifty-two outpatients were randomly assigned to an EP and ToM video-based training (n=27) or to a standard social cognitive rehabilitation treatment (n=24). They were assessed before and after 12 weeks of intervention and compared to a time-matched control group (n=24). Our results show a statistically significant improvement in ToM abilities, confirming the hypothesis of the enhancing potential of social cognitive interventions, but no changes with respect to EP; despite the need for a deeper examination, these data support further development of this treatment approach., (Copyright © 2012 Elsevier Ltd. All rights reserved.)

Cognitive impairment has been recognized since the earliest descriptions of schizophrenia as a core feature of the illness and different programmes have been developed to remediate these deficits. In all likelihood it is important for compliance and adherence to treatment that not only the patients but also their relatives be aware of the patients; cognitive deficits. Sixty-two patients with a diagnosis of schizophrenia and, for each one of them, one family member and an informant from the medical staff, were recruited and administered the Schizophrenia Cognition Rating Scale (SCoRS) ratings. Patients were tested for cognitive deficits with a neuropsychological battery and their performance was compared to the ratings of cognitive functioning provided by the patient himself, his family member and the informant. Results show no significant association between cognitive performance and SCoRS ratings in patients; only for executive functions the patient's performance was found to be predictive of the respective judgment on the SCoRS that was given by the relative. This is the first study to investigate awareness of the patients' cognitive deficits, both in the patients themselves and in their first degree relatives, through a direct comparison between subjective clinical ratings and objective measures of cognitive performances. When both patients and relatives are unaware of the patients' cognitive deficits, this could affect adherence to remediation treatment and need to be specifically addressed in future rehabilitation strategies., (Copyright © 2012 Elsevier Ltd. All rights reserved.)

Theory of Mind (ToM) abilities are known to be impaired in schizophrenia and data from functional brain imaging studies showed that ToM deficit is correlated to prefrontal cortex (PFC) dysfunction. Moreover, several lines of evidence suggest a critical role for dopaminergic-serotoninergic interactions at the PFC level. In this view, we aimed to analyse the specific effect of the -1019C/G functional polymorphism of the serotonin 1A receptor (5-HT1A-R), involved in both serotonin and dopamine transmission regulation. A total of 118 clinically stabilised schizophrenia patients was assessed with a neuropsychological battery, including evaluation of IQ, verbal memory, attention and executive function and a ToM task; they also underwent 5-HT1A-R genotyping. We observed a significant effect of the 5-HT1A-R genotype on ToM performances, with the CC genotype performing significantly better. The finding suggests an effect of the 5-HT1A-R polymorphism on ToM cognitive performance in schizophrenia patients, probably through complex interactions between dopaminergic and serotoninergic systems, involved in mentalising., (Copyright © 2010 Elsevier Ltd. All rights reserved.)

Background: Recently attention has been addressed to the role of 5-HT in cognition and several experimental studies revealed that manipulations of the central 5-HT system can produce quite specific changes in cognitive functioning. These results may suggest new treatment strategies to improve cognition in psychiatric conditions characterized by neuropsychological impairments, such as schizophrenia. It is possible to investigate the involvement of 5-HT in cognition by examining the impact of genetic variation in key regulators of serotoninergic neurotransmission. Among these, the serotonin transporter (5-HTT) presents a functional polymorphism in the transcriptional control region of the gene (5-HTTLPR) affecting transcriptional efficiency. In the present study, we aimed to analyze the effect of 5-HTTLPR polymorphism on specific cognitive functions, known to be affected by 5-HT manipulation and altered in schizophrenia., Methods: 223 schizophrenia patients were tested with Wisconsin Card Sorting Test (WCST), for the evaluation of cognitive flexibility, Continuous Performance Test (CPT), for the evaluation of attention, and genotyped for the 5-HTTLPR., Results: We found a significant association between HTT polymorphism and executive functions and inversely with sustained attention. The presence of the high-activity long (L) allele in homozygosis was a predictor of better executive performances and poorer performances of attention., Conclusions: Our findings suggest that factors affecting serotonin availability may play a specific role in cognitive processes, probably through complex modulation of the different performance components., (Copyright 2009 Elsevier Inc. All rights reserved.)

Background: Patients affected by schizophrenia show deficits in social cognition, with abnormal performance on tasks targeting theory of mind (ToM) and empathy (Emp). Brain imaging studies suggested that ToM and Emp depend on the activation of brain networks mainly localized at the superior temporal lobe and temporo-parietal junction., Methods: Participants included 24 schizophrenia patients and 20 control subjects. We used brain blood oxygen level dependent fMRI to study the neural responses to tasks targeting ToM and Emp. We then studied voxel-based morphometry of grey matter in areas where diagnosis influenced functional activation to both tasks. Outcomes were analyzed in the context of the general linear model, with global grey matter volume as nuisance covariate for structural MRI., Results: Patients showed worse performance on both tasks. We found significant effects of diagnosis on neural responses to the tasks in a wide cluster in right posterior superior temporal lobe (encompassing BA 22-42), in smaller clusters in left temporo-parietal junction and temporal pole (BA 38 and 39), and in a white matter region adjacent to medial prefrontal cortex (BA 10). A pattern of double dissociation of the effects of diagnosis and task on neural responses emerged. Among these areas, grey matter volume was found to be reduced in right superior temporal lobe regions of patients., Conclusions: Functional and structural abnormalities were observed in areas affected by the schizophrenic process early in the illness course, and known to be crucial for social cognition, suggesting a biological basis for social cognition deficits in schizophrenia.