Neural correlates of cognitive improvements following cognitive remediation in schizophrenia: a systematic review of randomized trials

Computerized cognitive remediation therapy on cognitive impairment and social function in patients with chronic schizophrenia

BACKGROUND

Patients with schizophrenia may have various disease manifestations, most of which gradually tend toward incurable chronic decline, leading to mental disability. The basic symptoms of the disease can impair social function, whereas long-term hospitalization produces hospitalization syndrome, causing serious damage to social function.

AIM

To investigate the effects of Computerized Cognitive Remediation Therapy (CCRT) on cognitive and social functioning in patients with chronic schizophrenia.

METHODS

A retrospective analysis of 120 patients with chronic schizophrenia in Shanghai Pudong New Area Mental Health Center was performed. They were divided into an intervention group (60 cases treated with CCRT combined with conventional medication) and a control group (60 cases treated with conventional medication). After treatment, effects on cognitive function and social roles were observed in both groups. The Positive and Negative Syndrome Scale (PANSS) was used to assess the patients' psychiatric symptoms. The Wisconsin Card Sorting Test (WCST) was used to assess the patients' cognitive functioning, and the Social Functioning Scale for Psychiatric Inpatients (SSPI) was used to assess the social functioning of the inpatient psychiatric patients.

RESULTS

No significant differences were observed in the PANSS, WCST, and SSPI intergroup scores before treatment (P > 0.05). After 2, 4, and 6 wk of therapy, general psychopathological factors, positive symptoms, negative symptoms, and total PANSS scores of PANSS in the intervention group were lower than in the control group (P < 0.05). After 2, 4, and 6 wk of treatment, the number of false responses, number of persistent bugs, and total responses in the WCST were significantly lower in the intervention group than in the control group (P < 0.05), and the amount of completed classification was significantly higher than in the control group (P < 0.05). After 2, 4, and 6 wk of therapy, the SSPI scores were significantly greater than those of the controls (P < 0.05). After 6 wk of treatment, the efficacy rates of the control and intervention groups were 81.67% and 91.67%, respectively. The curative effect in the intervention group was significantly higher than that in the control group (P < 0.05).

CONCLUSION

CCRT can significantly improve cognitive function and social abilities in patients with chronic schizophrenia.

Examining the impact of a group treatment using cognitive and social cognition remediation for young offenders: The justice health NSW school-link advantage pilot study

AIM

Young offenders experience higher rates of neurodevelopmental and mental health disorders than the general population, and significant access barriers to health treatment. Treatment combining Cognitive Remediation Therapy (CRT) and Social Cognition Remediation Therapy (SCRT) has demonstrated benefits for functional improvements and social development. However, there is limited information regarding group treatment programs in custodial settings for young offenders. This pilot study explores the effectiveness and feasibility of a group treatment program for youth offenders with cognitive deficits and mental health concerns in youth detention.

METHODS

The School-Link Advantage pilot study designed and tested a 10-week group treatment program combining CRT and SCRT for young offenders in custody. The closed groups incorporated interactive activities focussed on emotional recognition and regulation skills, optimizing executive functioning, understanding values, exploring belief systems, improving relationships, and safety planning.

RESULTS

Of the 22 male participants recruited in an Australian Youth Justice Centre, 12 completed all aspects of the treatment program, reflecting a 54.5% completion rate in a typically challenging to engage population cohort. Results demonstrated significant improvements in the ability to store and retrieve information, recognize information, and control emotions. Planning and organizing skills also showed considerable development.

CONCLUSIONS

This pilot study suggests that a combined CRT and SCRT group treatment program has the potential to effectively target cognitive challenges associated with mental health disorders in young offenders in custody. These promising outcomes suggest exploring randomized controlled trials with increased cultural sensitivity for diverse populations.

Cognitive remediation in schizophrenia: What happens after 10 years?

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.

Affective episodes in recently diagnosed patients with bipolar disorder associated with altered working memory-related prefrontal cortex activity: A longitudinal fMRI study

INTRODUCTION

Bipolar disorder (BD) is often accompanied by trait-related cognitive impairments, but it is unclear which neurocircuitry abnormalities give rise to these impairments and whether neurocircuitry differences are exacerbated with illness progression. This longitudinal fMRI study of recently diagnosed BD patients investigates whether aberrant working memory (WM) related activity in the cognitive control network is accentuated by new affective episodes.

METHODS

Forty-seven recently diagnosed BD patients in full or partial remission and 38 healthy controls were assessed with neurocognitive tests and fMRI during the performance of a verbal n-back WM task at baseline and follow-up (15.4 months in average).

RESULTS

Patients showed WM-related hypo-activity in dorsal prefrontal cortex (dPFC) and impaired cognitive function within attention and psychomotor speed, WM and executive function, and verbal learning and memory compared to controls at baseline. During the follow-up period, 26 patients experienced at least one affective episode (BD+), while 21 remained in remission (BD-). There was no deterioration in cognitive performance in BD+ compared to BD- patients. Nevertheless, BD+ displayed increased WM-related dPFC activity at follow-up compared with BD- patients. This change in dPFC response was independent of mood symptoms and medication.

LIMITATIONS

The study did not account for type or frequency of affective episodes.

CONCLUSION

The study identifies cognitive impairment and WM-related hypo-activity in dPFC early during the course of BD. Increased high-load WM related dPFC activity over the follow-up period in BD+ versus BD- patients in the absence of changes in cognitive performance may reflect an episode-related reduction in PFC efficiency.

Toward a transdiagnostic neurocircuitry-based biomarker model for pro-cognitive effects: challenges, opportunities, and next steps

Cognitive impairment has emerged as a key treatment priority in neuropsychiatric disorders. However, there is a lack of treatments with solid and lasting efficacy on cognition. A neurocircuitry-based biomarker model of pro-cognitive effects is critically needed to select among new candidate treatments. In a recent review of functional magnetic resonance imaging (fMRI) studies in mood disorders, we found that cognitive impairments are consistently accompanied by aberrant (hypo- and hyper-) activity in the dorsal prefrontal cortex (PFC) and the default mode network (DMN), and that activity change in these regions commonly occurs with cognitive improvements. Here, we (i) review the putative model from our recent review article, which explains the discrepant findings regarding the direction of aberrant dorsal PFC activity and treatment-related activity change in mood disorders. Inspired by the Research Domain Criteria project, we do this in order to (ii) examine whether a similar pattern of activity change occurs across distinct neuropsychiatric disorders and thereby provides a common biomarker for pro-cognitive effects. Lastly, we (iii) discuss whether dorsal PFC and DMN target engagement is a putative transdiagnostic neurocircuitry-based biomarker model for pro-cognitive effects, and (iv) outline the necessary next steps to address this question.

A multivariate neuromonitoring approach to neuroplasticity-based computerized cognitive training in recent onset psychosis

Two decades of studies suggest that computerized cognitive training (CCT) has an effect on cognitive improvement and the restoration of brain activity. Nevertheless, individual response to CCT remains heterogenous, and the predictive potential of neuroimaging in gauging response to CCT remains unknown. We employed multivariate pattern analysis (MVPA) on whole-brain resting-state functional connectivity (rsFC) to (neuro)monitor clinical outcome defined as psychosis-likeness change after 10-hours of CCT in recent onset psychosis (ROP) patients. Additionally, we investigated if sensory processing (SP) change during CCT is associated with individual psychosis-likeness change and cognitive gains after CCT. 26 ROP patients were divided into maintainers and improvers based on their SP change during CCT. A support vector machine (SVM) classifier separating 56 healthy controls (HC) from 35 ROP patients using rsFC (balanced accuracy of 65.5%, P < 0.01) was built in an independent sample to create a naturalistic model representing the HC-ROP hyperplane. This model was out-of-sample cross-validated in the ROP patients from the CCT trial to assess associations between rsFC pattern change, cognitive gains and SP during CCT. Patients with intact SP threshold at baseline showed improved attention despite psychosis status on the SVM hyperplane at follow-up (p < 0.05). Contrarily, the attentional gains occurred in the ROP patients who showed impaired SP at baseline only if rsfMRI diagnosis status shifted to the healthy-like side of the SVM continuum. Our results reveal the utility of MVPA for elucidating treatment response neuromarkers based on rsFC-SP change and pave the road to more personalized interventions.

Clinical and methodological considerations for psychological treatment of cognitive impairment in major depressive disorder

BACKGROUND

Cognitive impairment is considered a core feature of major depressive disorder (MDD) and research into psychological treatments aiming to address cognitive impairment are gaining momentum. Compared with the well-established research base of cognitive treatment trials in schizophrenia, including meta-analyses, mood disorder research is much more preliminary.

AIMS

To focus on identifying the important factors to consider in developing larger-scale psychological treatment trials targeting cognitive impairment in mood disorders. Trial design recommendations have been published for cognitive treatment trials in bipolar disorder.

METHOD

An in-depth discussion of methodological considerations in the development of cognitive treatment trials for MDD.

RESULTS

Methodological considerations include: screening for, and defining, cognitive impairment; mood state when cognitive intervention begins; medication monitoring during cognitive interventions; use of concomitant therapy; level of therapist involvement; duration and dose of treatment; choice of specific cognitive training exercises; home practice; improving adherence; appropriate comparison therapies in clinical trials; and choice of primary outcomes.

CONCLUSIONS

As well as guidance for clinical trial development, this review may be helpful for clinicians wanting to provide cognitive interventions for individuals with MDD.

Change in the Neural Response to Auditory Deviance Following Cognitive Therapy for Hallucinations in Patients With Schizophrenia

Adjunctive psychotherapeutic approaches recommended for patients with schizophrenia (SZ) who are fully or partially resistant to pharmacotherapy have rarely utilized biomarkers to enhance the understanding of treatment-effective mechanisms. As SZ patients with persistent auditory verbal hallucinations (AVH) frequently evidence reduced neural responsiveness to external auditory stimulation, which may impact cognitive and functional outcomes, this study examined the effects of cognitive behavioral therapy for voices (CBTv) on clinical and AVH symptoms and the sensory processing of auditory deviants as measured with the electroencephalographically derived mismatch negativity (MMN) response. Twenty-four patients with SZ and AVH were randomly assigned to group CBTv treatment or a treatment as usual (TAU) condition. Patients in the group CBTv condition received treatment for 5 months while the matched control patients received TAU for the same period, followed by 5 months of group CBTv. Assessments were conducted at baseline and at the end of treatment. Although not showing consistent changes in the frequency of AVHs, CBTv (vs. TAU) improved patients' appraisal (p = 0.001) of and behavioral/emotional responses to AVHs, and increased both MMN generation (p = 0.001) and auditory cortex current density (p = 0.002) in response to tone pitch deviants. Improvements in AVH symptoms were correlated with change in pitch deviant MMN and current density in left primary auditory cortex. These findings of improved auditory information processing and symptom-response attributable to CBTv suggest potential clinical and functional benefits of psychotherapeutical approaches for patients with persistent AVHs.

A Role for SERCA Pumps in the Neurobiology of Neuropsychiatric and Neurodegenerative Disorders

Calcium (Ca²⁺) is a fundamental regulator of cell fate and intracellular Ca²⁺ homeostasis is crucial for proper function of the nerve cells. Given the complexity of neurons, a constellation of mechanisms finely tunes the intracellular Ca²⁺ signaling. We are focusing on the sarco/endoplasmic reticulum (SR/ER) calcium (Ca²⁺)-ATPase (SERCA) pump, an integral ER protein. SERCA's well established role is to preserve low cytosolic Ca²⁺ levels ([Ca²⁺]_cyt), by pumping free Ca²⁺ ions into the ER lumen, utilizing ATP hydrolysis. The SERCA pumps are encoded by three distinct genes, SERCA1-3, resulting in 12 known protein isoforms, with tissue-dependent expression patterns. Despite the well-established structure and function of the SERCA pumps, their role in the central nervous system is not clear yet. Interestingly, SERCA-mediated Ca²⁺ dyshomeostasis has been associated with neuropathological conditions, such as bipolar disorder, schizophrenia, Parkinson's disease and Alzheimer's disease. We summarize here current evidence suggesting a role for SERCA in the neurobiology of neuropsychiatric and neurodegenerative disorders, thus highlighting the importance of this pump in brain physiology and pathophysiology.

White Matter Measures and Cognition in Schizophrenia

White matter (WM) abnormalities are commonly reported in schizophrenia but whether these arise from the axon or myelin compartments or both is not known. In addition, the relationship between WM abnormalities and cognitive function is not fully explored in this condition. We recruited 39 individuals with schizophrenia spectrum disorders and 37 healthy comparison subjects. All participants underwent MRI scanning at 4 Tesla to collect data in the prefrontal white matter on magnetization transfer ratio (MTR) and diffusion tensor spectroscopy (DTS) which provide information on myelin and axon compartments, respectively. We also collected Matrics Composite Cognitive Battery (MCCB) and Stroop cognitive data. We found an elevated N-acetylaspartate (NAA) apparent diffusion coefficient in schizophrenia in this cohort as in our previous work; we also observed poorer performance on both the MCCB composite and the Stroop in schizophrenia patients compared to controls. The MTR measure was correlated with the MCCB composite (r = 0.363, p = 0.032) and Stroop scores (r = 0.387, p = 0.029) in healthy individuals but not in schizophrenia. Since this is the first exploration of the relationship between these WM and cognitive measures, we consider our analyses exploratory and did not adjust for multiple comparisons; the findings are not statistically significant if adjusted for multiple comparisons. These findings indicate that WM integrity is associated with cognitive function in healthy individuals but this relationship breaks down in patients with schizophrenia.

Neuroimaging predictors of response to cognitive remediation and social skills training: A pilot study in veterans with schizophrenia

Neuroimaging may predict response to cognitive remediation therapy and social skills training (CRT + SST) in schizophrenia. Identifying biological predictors of response is crucial for treatment decision making given not all patients respond to such interventions. Nineteen veterans with schizophrenia enrolled in an 8-week trial of CRT + SST. Ten participants completed diffusion tensor imaging (DTI) at baseline. Baseline fractional anisotropy (FA) in the superior longitudinal fasciculus (SLF) and overall average FA predicted improvements in visual-spatial working memory, and social cognition, respectively. Neuroimaging may be useful in identifying therapeutic targets in schizophrenia.

Retrieval practice improves memory in patients with schizophrenia: new perspectives for cognitive remediation

BACKGROUND

Schizophrenia is associated with severe cognitive deficits, particularly episodic memory deficits, that interfere with patients' socio-professional functioning. Retrieval practice (also known as testing effect) is a well-established episodic memory strategy that involves taking an initial memory test on a previously learned material. Testing later produces robust long-term memory improvements in comparison to the restudy of the same material both in healthy subjects and in some clinical populations with memory deficits. While retrieval practice might represent a relevant cognitive remediation strategy in patients with schizophrenia, studies using optimal procedures to explore the benefits of retrieval practice in this population are still lacking. Therefore, the purpose of our study was to investigate the benefits of retrieval practice in patients with schizophrenia.

METHODS

Nineteen stabilised outpatients with schizophrenia (DSM-5 criteria) and 20 healthy controls first studied a list of 60 word-pairs (30 pairs with weak semantic association and 30 non associated pairs). Half the pairs were studied again (restudy condition), while only the first word of the pair was presented and the subject had to recall the second word for the other half (retrieval practice condition). The final memory test consisted in a cued-recall which took place 2 days later. Statistical analyses were performed using Bayesian methods.

RESULTS

Cognitive performances were globally altered in patients. However, in both groups, memory performances for word-pairs were significantly better after retrieval practice than after restudy (56.1% vs 35.7%, respectively, Pr(RP > RS) > 0.999), and when a weak semantic association was present (64.7% vs 27.1%, respectively; Pr(weak > no) > 0.999). Moreover, the positive effect of RP was observed in all patients but one.

CONCLUSIONS

Our study is the first to demonstrate that retrieval practice efficiently improves episodic memory in comparison to restudy in patients with schizophrenia. This learning strategy should therefore be considered as a useful tool for cognitive remediation programs. In this perspective, future studies might explore retrieval practice using more ecological material.

Inefficient neural system stabilization: a theory of spontaneous resolutions and recurrent relapses in psychosis

A striking feature of psychosis is its heterogeneity. Presentations of psychosis vary from transient symptoms with no functional consequence in the general population to a tenacious illness at the other extreme, with a wide range of variable trajectories in between. Even among patients with schizophrenia, who are diagnosed on the basis of persistent deterioration, marked variation is seen in response to treatment, frequency of relapses and degree of eventual recovery. Existing theoretical accounts of psychosis focus almost exclusively on how symptoms are initially formed, with much less emphasis on explaining their variable course. In this review, I present an account that links several existing notions of the biology of psychosis with the variant clinical trajectories. My aim is to incorporate perspectives of systems neuroscience in a staging framework to explain the individual variations in illness course that follow the onset of psychosis.

Computer-assisted cognitive remediation therapy for patients with schizophrenia induces microstructural changes in cerebellar regions involved in cognitive functions

Previous studies have reported that cognitive remediation therapy (CRT) improves cognitive deficits in patents with schizophrenia. However, few studies have focused on the underlying structural alterations in the brain following Vocational Cognitive Ability Training by the Japanese Cognitive Rehabilitation Program for Schizophrenia (VCAT-J). In this study, we analyzed changes in diffusion tensor imaging parameters in 31 patients with schizophrenia after 12 weeks of intervention consisting of standard treatment alone or standard treatment plus VCAT-J, in order to determine the effect of the latter on white matter microstructural plasticity. Cognitive function was evaluated using the Japanese version of the Brief Assessment of Cognition in Schizophrenia (BACS-J) scale. The CRT group exhibited significant improvements in verbal fluency and composite BACS-J scores, relative to the treatment-as-usual (TAU) group. In addition, the CRT group exhibited significantly increased fractional anisotropy (FA) values, along with significantly decreased radial (RD) and mean diffusivity (MD) values, in the posterior lobe of the left cerebellum. Changes in RD and MD values were negatively correlated with changes in BACS-J composite scores. These suggest that VCAT-J might mediate improvements in myelin sheath composition in the posterior lobe of the left cerebellum, which may have been associated with improvements in cognitive function.

Neurocognitive endophenotypes in schizophrenia and bipolar disorder: A systematic review of longitudinal family studies

Although there is substantial evidence supporting the existence of neurocognitive impairment in patients diagnosed with schizophrenia (SZ) and bipolar disorder (BD), few studies have explored the field from an endophenotypic perspective. The present systematic review sought to identify longitudinal family studies exploring suitable neurocognitive endophenotypes in unaffected relatives of patients with SZ and/or BD. Following the PRISMA statement, only five follow-up studies met the inclusion criteria, comprising 79 SZ patients, 159 SZ unaffected relatives of SZ, 131 BD patients, 77 unaffected relatives of BD, and 248 controls. Verbal memory, auditory attention, face memory and emotion processing were found as putative endophenotypic candidates for SZ, whereas this strategy identified none for BD. Substantial heterogeneity and lack of standardization in global neurocognitive assessment within this area should be pointed out; nevertheless, several candidate endophenotypes were identified for SZ, except for executive impairment.

Effects of peer social interaction on performance during computerized cognitive remediation therapy in patients with early course schizophrenia: A pilot study

BACKGROUND

Recent studies show that computer-based training enhances cognition in schizophrenia; furthermore, socialization has also been found to improve cognitive functions. It is generally believed that non-social cognitive remediation using computer exercises would be a pre-requisite for therapeutic benefits from social cognitive training. However, it is also possible that social interaction by itself enhances non-social cognitive functions; this possibility has scarcely been explored in schizophrenia patients. This pilot study examined the effects of computer-based neurocognitive training, along with social interaction either with a peer (PSI) or without one (N-PSI). We hypothesized that PSI will enhance cognitive performance during computerized exercises in schizophrenia, as compared with N-PSI.

METHODS

Sixteen adult participants diagnosed with schizophrenia or schizoaffective disorder participating in an ongoing trial of Cognitive Enhancement Therapy completed several computerized neurocognitive remediation training sessions (the Orientation Remedial Module©, or ORM), either with a peer or without a peer.

RESULTS

We observed a significant interaction between the effect of PSI and performance on the different cognitive exercises (p<0.05). More precisely, when patients performed the session with PSI, they demonstrated better cognitive performances than with N-PSI in the ORM exercise that provides training in processing speed, alertness, and reaction time (the standard Attention Reaction Conditioner, or ARC) (p<0.01, corrected). PSI did not significantly affect other cognitive domains such as target detection and spatial attention.

CONCLUSION

Our findings suggest that PSI could improve cognitive performance, such as processing speed, during computerized cognitive training in schizophrenia. Additional studies investigating the effect of PSI during cognitive remediation are needed to further evaluate this hypothesis.

Improving neurocognitive functioning in schizophrenia by addition of cognitive remediation therapy to a standard treatment of metacognitive training

Cognitive dysfunctions are a common clinical feature of schizophrenia and represent important indicators of outcome among patients who are affected. Therefore, a randomized, controlled, monocentric, singleblind trial was carried out to compare two different rehabilitation strategies adopted for the restoration and recovery of cognitive functioning of residential patients with schizophrenia. A sample of 110 residential patients were selected and, during the experimental period, a group of 55 patients was treated with sets of domain-specific exercises (SRT+CRT), whereas an equal control group was treated with sets of nondomain- specific exercises (SRT+PBO) belonging to the Cogpack® software. The effects on the scores (between T0 and T1) of the variables treatment and time and of the interaction time X treatment were analyzed: for the total BACS, the main effect of the between-factors variable treatment is statistically significant (F=201.562 P=0.000), as well as the effect of the within-factors variable “time” (F=496.68 P=0.000).The interaction of these two factors is also statistically significant (F=299.594 P=0.000). The addition of cognitive remediation therapy (CRT) to a standard treatment of metacognitive training (MCT) resulted in a significant improvement in global neurocognitive functioning and has reported positive effects with regard to the strengthening of verbal and working memory, selective and sustained attention at T1. A relevant result is the statistically significance of “time X treatment” for all the tests administered: we can assume that the domain-specific cognitive training amplifies the effects of SRT, as the primary and secondary goals of the present study were achieved.

Towards a biomarker model for cognitive improvement: No change in memory-related prefrontal engagement following a negative cognitive remediation trial in bipolar disorder

BACKGROUND

Cognitive deficits are prevalent in bipolar disorder during remission but effective cognition treatments are lacking due to insufficient insight into the neurobiological targets of cognitive improvement. Emerging data suggest that dorsal prefrontal cortex target engagement is a key neurocircuitry biomarker of pro-cognitive treatment effects.

AIMS

In this randomized controlled functional magnetic resonance imaging study, we test this hypothesis by investigating the effects of an ineffective cognitive remediation intervention on dorsal prefrontal response during strategic memory encoding and working memory engagement.

METHODS

Bipolar disorder patients in partial remission with subjective cognitive difficulties were randomized to receive 12-week group-based cognitive remediation ( n = 13) or to continue their standard treatment ( n = 14). The patients performed a strategic episodic picture encoding task and a spatial n-back working memory task under functional magnetic resonance imaging at baseline and following cognitive remediation or standard treatment.

RESULTS

The right dorsolateral prefrontal cortex was commonly activated by both strategic memory tasks across all patients. The task-related prefrontal engagement was not altered by cognitive remediation relative to standard treatment. The dorsolateral prefrontal cortex response was not significantly associated with recall accuracy or working memory performance.

CONCLUSIONS

As hypothesized, no task-related change in prefrontal activity was observed in a negative cognitive remediation trial in remitted bipolar disorder patients. By complementing previous findings linking cognitive improvement with increased dorsolateral prefrontal cortex engagement, our negative findings provide additional validity evidence to the dorsal prefrontal target engagement biomarker model of cognitive improvement by strengthening the proposed causality between modulation of dorsolateral prefrontal cortex engagement and pro-cognitive effects.

Metaphor Comprehension in Schizophrenic Patients

People with schizophrenia often exhibit difficulties to comprehend figurative expressions, such as irony, proverbs, metaphors and idioms, with a general proneness to neglect the figurative meaning and to accept the more literal one. This inability is usually referred to as concretism and it constitutes a clinical manifestation of the broader language dysfunction called Formal Thought Disorder. The current review focuses on the neuropsychological and neuroanatomical underpinnings of schizophrenics’ misinterpretation of a subgroup of figurative expressions, i.e., metaphors. Metaphors are heterogeneous in nature, classifiable according to various criteria; for instance, metaphors can be conventional and familiar, or conversely, novel and unusual. These linguistic distinctions are substantial because the comprehension of the different types of metaphor entails partially different cognitive strategies and neural substrates. This review gathers studies that have directly investigated which neurocognitive deficits explain the inefficient comprehension of metaphor in schizophrenia. Several impairments have been put forward, such as general intelligence, executive functions and theory of mind deficits. Moreover, the neural correlates of metaphor comprehension in schizophrenia, like the left inferior/medial frontal gyrus and the temporal lobe, match those cortices affected by the neuropathology of schizophrenia. Even though the causal defective mechanism is still a matter of investigation, we provide an attempt to integrate existing findings.

Effectiveness of a low support, remotely accessible, cognitive remediation training programme for chronic psychosis: cognitive, functional and cortical outcomes from a single blind randomised controlled trial

BACKGROUND

Cognitive remediation (CR) training has emerged as a promising approach to improving cognitive deficits in schizophrenia and related psychosis. The limited availability of psychological services for psychosis is a major barrier to accessing this intervention however. This study investigated the effectiveness of a low support, remotely accessible, computerised working memory (WM) training programme in patients with psychosis.

METHODS

Ninety patients were enrolled into a single blind randomised controlled trial of CR. Effectiveness of the intervention was assessed in terms of neuropsychological performance, social and occupational function, and functional MRI 2 weeks post-intervention, with neuropsychological and social function again assessed 3-6 months post-treatment.

RESULTS

Patients who completed the intervention showed significant gains in both neuropsychological function (measured using both untrained WM and episodic task performance, and a measure of performance IQ), and social function at both 2-week follow-up and 3-6-month follow-up timepoints. Furthermore, patients who completed MRI scanning showed improved resting state functional connectivity relative to patients in the placebo condition.

CONCLUSIONS

CR training has already been shown to improve cognitive and social function in patient with psychosis. This study demonstrates that, at least for some chronic but stable outpatients, a low support treatment was associated with gains that were comparable with those reported for CR delivered entirely on a 1:1 basis. We conclude that CR has potential to be delivered even in services in which psychological supports for patients with psychosis are limited.

The impact of cognitive remediation on cerebral activity in schizophrenia: Systematic review of the literature

CONTEXT

cognitive remediation involves either intensive training of impaired functions or implementing strategies to compensate for these impairments. In cases of schizophrenia, both methods have demonstrated benefits in terms of behavior and cerebral activity. However, despite the major differences between these two approaches, their impact has not yet been compared.

METHOD

We searched the PsychInfo, Pubmed, and ScienceDirect databases using the key words "cognitive remediation," "schizophrenia," "cerebral activity," and "magnetic resonance imaging," in order to select studies investigating the effects of cognitive remediation on patients with schizophrenia. The studies selected had to present their approach in detail and measure its impact in terms of both cerebral activity and cognitive function, both before and after therapy. We divided the studies into two groups, those using the strategy method and those using the training method.

RESULTS

Eight studies were included in the review, four for the strategy method (88 patients, 44 of whom underwent remediation) and 4 for the training method (87 patients, 43 of whom underwent remediation). The analysis of the results of this study indicates that the training method is capable of activating more the targeted brain areas than the strategy method. However, the latter appears to encourage more extensive activation of the cerebral networks.

DISCUSSION

The studies used for this review vary widely in terms of the imaging methods and protocol. However, differences were found between the two methods and lead us to suggest that further studies, with proper bias control, should be conducted to systematically compare the two approaches.

Cognitive Deficits in Schizophrenia: Understanding the Biological Correlates and Remediation Strategies

Cognitive deficits are one of the core symptoms of schizophrenia that evolve during the course of schizophrenia, after being originated even before the onset of illness. Existing pharmacological and biological treatment modalities fall short to meet the needs to improve the cognitive symptoms; hence, various cognitive remediation strategies have been adopted to address these deficits. Research evidences suggest that cognitive remediation measures improve the functioning, limit disability bettering the quality of life. The functional outcomes of cognitive remediation in schizophrenia are resultant of neurobiological changes in specific brain areas. Recent years witnessed significant innovations in cognitive remediation strategies in schizophrenia. This comprehensive review highlights the biological correlates of cognitive deficits in schizophrenia and the remedial measures with evidence base.

Comparative Analysis of Gene Expression Profiles Involved in Calcium Signaling Pathways Using the NLVH Animal Model of Schizophrenia

In this study, we evaluated the expression profile changes of genes that intervene in the calcium signaling pathway, in young and adult Wistar rats, using the animal model of neonatal lesion in ventral hippocampus (NLVH) (a recognized animal model for schizophrenia) and compared to the group of control animals (Sham). Through microarray technology, gene expression profiles were obtained from the three brain areas (nucleus accumbens, prefrontal cortex, and hippocampus) of young male Wistar rats (45 days) and adults (90 days) whether or not subjected to NLVH. The calcium signaling pathway reported a greater number of differentially expressed genes with z-score two values, > 2 (over-expression) and < - 2 (under-expression), in the three evaluated areas. The comparative analyses of this approach were performed in juvenile and adult rats with ventral hippocampal lesion in neonate rats (NLVH). NLVH influenced change expressions in various genes involved in Ca²⁺ homeostasis, including Cacna1d, Atp2a2, Adcy2, Ppp3cb, and Ptk2b. The expression of Adcy2, Ppp3cb, and Ptk2b genes changed in both age groups; therefore, the study of gene expression profiles between juvenile and adult rats may help to understand the molecular mechanisms of schizophrenia.

Neuroimaging studies of cognitive remediation in schizophrenia: A systematic and critical review

AIM

To examine the effects of cognitive remediation therapies on brain functioning through neuroimaging procedures in patients with schizophrenia.

METHODS

A systematic, computerised literature search was conducted in the PubMed/Medline and PsychInfo databases. The search was performed through February 2016 without any restrictions on language or publication date. The search was performed using the following search terms: [(“cogniti*” and “remediation” or “training” or “enhancement”) and (“fMRI” or “MRI” or “PET” or “SPECT”) and (schizophrenia or schiz*)]. The search was accompanied by a manual online search and a review of the references from each of the papers selected, and those papers fulfilling our inclusion criteria were also included.

RESULTS

A total of 101 studies were found, but only 18 of them fulfilled the inclusion criteria. These studies indicated that cognitive remediation improves brain activation in neuroimaging studies. The most commonly reported changes were those that involved the prefrontal and thalamic regions. Those findings are in agreement with the hypofrontality hypothesis, which proposes that frontal hypoactivation is the underlying mechanism of cognitive impairments in schizophrenia. Nonetheless, great heterogeneity among the studies was found. They presented different hypotheses, different results and different findings. The results of more recent studies interpreted cognitive recovery within broader frameworks, namely, as amelioration of the efficiency of different networks. Furthermore, advances in neuroimaging methodologies, such as the use of whole-brain analysis, tractography, graph analysis, and other sophisticated methodologies of data processing, might be conditioning the interpretation of results and generating new theoretical frameworks. Additionally, structural changes were described in both the grey and white matter, suggesting a neuroprotective effect of cognitive remediation. Cognitive, functional and structural improvements tended to be positively correlated.

CONCLUSION

Neuroimaging studies of cognitive remediation in patients with schizophrenia suggest a positive effect on brain functioning in terms of the functional reorganisation of neural networks.

Neuroanatomical Predictors of Functional Outcome in Individuals at Ultra-High Risk for Psychosis

Most individuals at ultra-high risk (UHR) for psychosis do not transition to frank illness. Nevertheless, many have poor clinical outcomes and impaired psychosocial functioning. This study used voxel-based morphometry to investigate if baseline grey and white matter brain densities at identification as UHR were associated with functional outcome at medium- to long-term follow-up. Participants were help-seeking UHR individuals (n = 109, 54M:55F) who underwent magnetic resonance imaging at baseline; functional outcome was assessed an average of 9.2 years later. Primary analysis showed that lower baseline grey matter density, but not white matter density, in bilateral frontal and limbic areas, and left cerebellar declive were associated with poorer functional outcome (Social and Occupational Functioning Assessment Scale [SOFAS]). These findings were independent of transition to psychosis or persistence of the at-risk mental state. Similar regions were significantly associated with lower self-reported levels of social functioning and increased negative symptoms at follow-up. Exploratory analyses showed that lower baseline grey matter densities in middle and inferior frontal gyri were significantly associated with decline in Global Assessment of Functioning (GAF) score over follow-up. There was no association between baseline grey matter density and IQ or positive symptoms at follow-up. The current findings provide novel evidence that those with the poorest functional outcomes have the lowest grey matter densities at identification as UHR, regardless of transition status or persistence of the at-risk mental state. Replication and validation of these findings may allow for early identification of poor functional outcome and targeted interventions.