Cognitive remediation and brain connectivity: A resting-state fMRI study in patients with schizophrenia

Changes in BDNF methylation patterns after cognitive remediation therapy in schizophrenia: A randomized and controlled trial

Although cognitive remediation therapy (CRT) produces cognitive benefits in schizophrenia, we do not yet understand whether molecular changes are associated with this cognitive improvement. A gene central to synaptic plasticity, the BDNF, has been proposed as one potential route. This study assesses whether BDNF methylation changes following CRT-produced cognitive improvement are detected. A randomized and controlled trial was performed with two groups (CRT, n = 40; TAU: Treatment as Usual, n = 20) on a sample of participants with schizophrenia. CRT was delivered by trained therapists using a web-based computerized program. Mixed Models, where the interaction of treatment (CRT, TAU) by time (T0: 0 weeks, T1: 16 weeks) was the main effect were used. Then, we tested the association between the treatment and methylation changes in three CpG islands of the BDNF gene. CRT group showed significant improvements in some cognitive domains. Between-groups differential changes in 5 CpG units over time were found, 4 in island 1 (CpG1.2, CpG1.7, CpG1.10, CpG1.17) and 1 in island 3 (CpG3.2). CRT group showed increases in methylation in CpG1.2, CpG1.7 and decreases in pG1.10, CpG1.17, and CpG3.2. Differences in the degree of methylation were associated with changes in Speed of Processing, Working Memory, and Verbal Learning within the CRT group. Those findings provide new data on the relationship between cognitive improvement and changes in peripheral methylation levels of BDNF gene, a key factor involved in neuroplasticity regulation. Trial Registration: NCT04278027.

Exploring the Effectiveness of Group Cognitive Stimulation Training in People With Schizophrenia: A Randomized Controlled Trial

BACKGROUND

Schizophrenia is a chronic degenerative brain disease. Cognitive impairment, the core symptom of this disease, affects the mood and social functioning of patients severely. Nonpharmacological therapies that both improve cognitive function and are suitable for patients with schizophrenia remain underdeveloped.

PURPOSE

This article was designed to explore the effects of group cognitive stimulation training (GCST) on cognitive function and social function in people with schizophrenia.

METHODS

A randomized controlled trial was conducted. The 76 participants were allocated into either the experimental or control group using blocked randomization. The participants were all patients with chronic schizophrenia recruited from seven rehabilitation units in northern Taiwan who were 20-65 years old and scored 10-25 on the Montreal Cognitive Assessment Taiwan Version. The experimental group received the 60-minute GCST twice a week for 7 weeks, whereas the control group received standard treatment. All outcome indicators were analyzed at baseline and after intervention using generalized estimating equations. The primary outcome indicators included cognitive function assessed using the Taiwan version of the Montreal Cognitive Assessment, working memory assessed using the Wechsler Memory Scale-Third Edition, and executive function assessed using the Taiwanese version of the Frontal Assessment Battery. The secondary outcome indicator was social function assessed using the Social Function Scale-Taiwan short version.

RESULTS

Generalized estimating equation modeling revealed the experimental group exhibited significant improvement in Montreal Cognitive Assessment total score ( B = 1.33, SE = 0.65, p = .040) and Social Function Scale-Taiwan short version ( B = 9.55, SE = 2.38, p < .001) after adjusting for nine covariates. No significant differences between the two groups in terms of working memory ( B = 4.79, SE = 2.66, p = .071) or executive function ( B = 0.53, SE = 0.63, p = .399) were found.

CONCLUSIONS/IMPLICATIONS FOR PRACTICE

The results indicate that GCST positively impacts overall cognitive and social functions but not higher-order cognitive function (working memory and executive function). In clinical settings, GCST may be applied to improve cognitive function in people with schizophrenia. The findings of this study may inform the practice of mental health nurses to improve cognitive function in patients in clinical care.

Analyzing structural and functional brain changes related to an integrative cognitive remediation program for schizophrenia: A randomized controlled trial

Cognitive remediation has been shown to improve cognition in schizophrenia, but little is known about the specific functional and structural brain changes related to the implementation of an integrative cognitive remediation program. This study analyzed the functional and structural brain changes identified after implementing an integrative cognitive remediation program, REHACOP, in schizophrenia. The program combined cognitive remediation, social cognitive training, and functional and social skills training. The sample included 59 patients that were assigned to either the REHACOP group or an active control group for 20 weeks. In addition to a clinical and neuropsychological assessment, T1-weighted, diffusion-weighted and functional magnetic resonance images were acquired during a resting-state and during a memory paradigm, both at baseline and follow-up. Voxel-based morphometry, tract-based spatial statistics, resting-state functional connectivity, and brain activation analyses during the memory paradigm were performed. Brain changes were assessed with a 2 × 2 repeated-measure analysis of covariance for group x time interaction. Intragroup paired t-tests were also carried out. Repeated-measure analyses revealed improvements in cognition and functional outcome, but no significant brain changes associated with the integrative cognitive remediation program. Intragroup analyses showed greater gray matter volume and cortical thickness in right temporal regions at post-treatment in the REHACOP group. The absence of significant brain-level results associated with cognitive remediation may be partly due to the small sample size, which limited the statistical power of the study. Therefore, further research is needed to clarify whether the temporal lobe may be a key area involved in cognitive improvements following cognitive remediation.

A deep residual model for characterization of 5D spatiotemporal network dynamics reveals widespread spatiodynamic changes in schizophrenia

Schizophrenia is a severe brain disorder with serious symptoms including delusions, disorganized speech, and hallucinations that can have a long-term detrimental impact on different aspects of a patient's life. It is still unclear what the main cause of schizophrenia is, but a combination of altered brain connectivity and structure may play a role. Neuroimaging data has been useful in characterizing schizophrenia, but there has been very little work focused on voxel-wise changes in multiple brain networks over time, despite evidence that functional networks exhibit complex spatiotemporal changes over time within individual subjects. Recent studies have primarily focused on static (average) features of functional data or on temporal variations between fixed networks; however, such approaches are not able to capture multiple overlapping networks which change at the voxel level. In this work, we employ a deep residual convolutional neural network (CNN) model to extract 53 different spatiotemporal networks each of which captures dynamism within various domains including subcortical, cerebellar, visual, sensori-motor, auditory, cognitive control, and default mode. We apply this approach to study spatiotemporal brain dynamism at the voxel level within multiple functional networks extracted from a large functional magnetic resonance imaging (fMRI) dataset of individuals with schizophrenia (N = 708) and controls (N = 510). Our analysis reveals widespread group level differences across multiple networks and spatiotemporal features including voxel-wise variability, magnitude, and temporal functional network connectivity in widespread regions expected to be impacted by the disorder. We compare with typical average spatial amplitude and show highly structured and neuroanatomically relevant results are missed if one does not consider the voxel-wise spatial dynamics. Importantly, our approach can summarize static, temporal dynamic, spatial dynamic, and spatiotemporal dynamics features, thus proving a powerful approach to unify and compare these various perspectives. In sum, we show the proposed approach highlights the importance of accounting for both temporal and spatial dynamism in whole brain neuroimaging data generally, shows a high-level of sensitivity to schizophrenia highlighting global but spatially unique dynamics showing group differences, and may be especially important in studies focused on the development of brain-based biomarkers.

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.

Cognitive dysfunction in schizophrenia: An expert group paper on the current state of the art

Cognitive impairment in schizophrenia represents one of the main obstacles to clinical and functional recovery. This expert group paper brings together experts in schizophrenia treatment to discuss scientific progress in the domain of cognitive impairment to address cognitive impairments and their consequences in the most effective way. We report on the onset and course of cognitive deficits, linking them to the alterations in brain function and structure in schizophrenia and discussing their role in predicting the transition to psychosis in people at risk. We then address the assessment tools with reference to functioning and social cognition, examining the role of subjective measures and addressing new methods for measuring functional outcomes including technology based approaches. Finally, we briefly review treatment options for cognitive deficits, focusing on cognitive remediation programs, highlighting their effects on brain activity and conclude with the potential benefit of individualized integrated interventions combing cognitive remediation with other approaches.

Dynamic Changes of Brain Networks during Working Memory Tasks in Schizophrenia

Electroencephalograph (EEG) signals and graph theory measures have been widely used to characterize the brain functional networks of healthy individuals and patients by calculating the correlations between different electrodes over an entire time series. Although EEG signals have a high temporal resolution and can provide relatively stable results, the process of constructing and analyzing brain functional networks is inevitably complicated by high time complexity. Our goal in this research was to distinguish the brain function networks of schizophrenia patients from those of healthy participants during working memory tasks. Consequently, we utilized a method involving microstates, which are each characterized by a unique topography of electric potentials over an entire channel array, to reduce the dimension of the EEG signals during working memory tasks and then compared and analyzed the brain functional networks using the microstates time series (MTS) and original time series (OTS) of the schizophrenia patients and healthy individuals. We found that the right frontal and parietal-occipital regions neurons of the schizophrenia patients were less active than those of the healthy participants during working memory tasks. Notably, compared with OTS, the time needed to construct the brain functional networks was significantly reduced by using MTS. In conclusion, our results show that, like OTS, MTS can well distinguish the brain functional network of schizophrenia patients from those of healthy individuals during working memory tasks while greatly decreasing time complexity. MTS can thus provide a method for characterizing the original time series for the construction and analysis of EEG brain functional networks.