Cognitive remediation for individuals with psychosis: efficacy and mechanisms of treatment effects

Associations between learning principles of cognitive remediation and cognitive and vocational outcomes in early psychosis-an exploratory analysis of RCT data

Background: Most cognitive remediation (CR) programs are based on multiple scientific learning principles. The role of those learning principles in the beneficial effects of CR is poorly understood. A better understanding of such underlying mechanisms is important to further tailor the intervention and to learn about optimal contexts.Method: An explorative secondary analysis was conducted of data from a randomized controlled trial (RCT) comparing the effects of Individual Placement and Support (IPS) with and without CR. The present study evaluated how CR learning principles of "massed practice," "errorless learning," "strategy use" and "therapist contribution" (therapist fidelity) were associated with cognitive and vocational outcomes within 26 participants in this RCT who were treatment exposed.Results: Cognitive gains after CR were positively associated with "massed practice" and "errorless learning." Negative associations were found with "strategy use" and "therapist fidelity." No direct relationship was found between CR principles and vocational outcomes.Conclusions: Results tentatively suggest that CR is most effective and efficient with a good balance between sufficient intensity, of more than 200 tasks, and a limited duration of the training up to 20 h, using tasks that remain both challenging and rewarding, being applied in a context that facilitates real-life practice.

Magnocellular and parvocellular contributions to brain network dysfunction during learning and memory: Implications for schizophrenia

Memory deficits are core features of schizophrenia, and a central aim in biological psychiatry is to identify the etiology of these deficits. Scrutiny is naturally focused on the dorsolateral prefrontal cortex and the hippocampal cortices, given these structures' roles in memory and learning. The fronto-hippocampal framework is valuable but restrictive. Network-based underpinnings of learning and memory are substantially diverse and include interactions between hetero-modal and early sensory networks. Thus, a loss of fidelity in sensory information may impact memorial and cognitive processing in higher-order brain sub-networks, becoming a sensory source for learning and memory deficits. In this overview, we suggest that impairments in magno- and parvo-cellular visual pathways result in degraded inputs to core learning and memory networks. The ascending cascade of aberrant neural events significantly contributes to learning and memory deficits in schizophrenia. We outline the network bases of these effects, and suggest that any network perspectives of dysfunction in schizophrenia must assess the impact of impaired perceptual contributions. Finally, we speculate on how this framework enriches the space of biomarkers and expands intervention strategies to ameliorate this prototypical disconnection syndrome.

Verbal memory performance predicts remission and functional outcome in people at clinical high-risk for psychosis

Robust deficits in cognitive functioning are present in people with psychosis and are evident in the early stages of the disorder. Impairments in verbal memory and verbal fluency are reliably seen in individuals at clinical high-risk for psychosis (CHR) compared to healthy populations. As previous studies have shown a relationship between cognition and longer-term outcomes in schizophrenia, the aim of this paper was to explore whether verbal memory and verbal fluency performance predicted outcomes in a large CHR sample recruited as part of the EU-GEI High Risk Study. Participants included 316 CHR individuals, 90.8% of whom were not currently on antipsychotic medication, and 60 healthy controls. Verbal memory and verbal fluency performance were measured at baseline. At two-year follow-up, CHR individuals were assessed by three different outcome measures, those who did and did not (1) transition to psychosis, (2) experience burdening impairment or disabilities, or (3) remit clinically from CHR status. Individuals with CHR displayed significant verbal memory and verbal fluency deficits at baseline compared to healthy controls (Hedges' g effect size = 0.24 to 0.66). There were no significant differences in cognitive performance of those who did and did not transition to psychosis. However, impaired immediate verbal recall predicted both functional disability and non-remission from the CHR state. Results remained significant when analyses were restricted to only include antipsychotic-free CHR participants. These findings may inform the development of early interventions designed to improve cognitive deficits in the early stages of psychosis.

A meta-analysis on neural changes of cognitive training for mental disorders in executive function tasks: increase or decrease brain activation?

BACKGROUND

Cognitive impairment is often found in patients with psychiatric disorders, and cognitive training (CT) has been shown to help these patients. To better understand the mechanisms of CT, many neuroimaging studies have investigated the neural changes associated with it. However, the results of those studies have been inconsistent, making it difficult to draw conclusions from the literature. Therefore, the objective of this meta-analysis was to identify consistent patterns in the literature of neural changes associated with CT for psychiatric disorders.

METHODS

We searched for cognitive training imaging studies in PubMed, Cochrane library, Scopus, and ProQuest electronic databases. We conducted an activation likelihood estimation (ALE) for coordinate-based meta-analysis of neuroimaging studies, conduct behavioral analysis of brain regions identified by ALE analysis, conduct behavioral analysis of brain regions identified by ALE analysis, and then created a functional meta-analytic connectivity model (fMACM) of the resulting regions.

RESULTS

Results showed that CT studies consistently reported increased activation in the left inferior frontal gyrus (IFG) and decreased activation in the left precuneus and cuneus from pre- to post- CT.

CONCLUSION

CT improves cognitive function by supporting language and memory function, and reducing neuronal resources associated with basic visual processing.

Computerized or manual? Long term effects of cognitive remediation on schizophrenia

BACKGROUND

Cognitive remediation therapy (CRT) and Computerized CRT (CCRT) improve cognition and functioning, but there is no direct evidence of whether there is an advantage of using a computer. This study fills this gap and extends research evidence to the long-term effect of these two treatments in a large sample of Chinese inpatients with a diagnosis of schizophrenia.

METHOD

We conducted a randomized single-blind, follow-up study with participants randomized to receive CCRT (n = 144), CRT (n = 72) or Active control (n = 54) for 12 weeks with 4-5 sessions per week. The main outcome was cognition (MATRICS Consensus Cognitive Battery total score, MCCB), and secondary outcomes were cognitive domains, symptoms and functioning assessed at baseline (0 month), post-treatment (3 months) and follow-up (6, 12 and 18 months).

RESULTS

The primary outcome (MCCB total score) improved in both treatment groups which was maintained at 18 months but did not differ between treatment groups. Post hoc analysis demonstrated that the CRT group had an advantage over CCRT for the Trail Making and Symbol Coding Tests (all p < 0.05), which lasted for almost 18 months.

CONCLUSIONS

Both CCRT and CRT contribute to general cognitive improvements in schizophrenia and the overall efficacy was similar. The effects were maintained for 18th months. Exploratory analyses revealed few differences except that CRT had a processing speed advantage.

Strategies for Psychiatric Rehabilitation and their Cognitive Outcomes in Schizophrenia: Review of Last Five-year Studies

BACKGROUND

Cognitive deficits are core features of Schizophrenia, showing poor response to antipsychotic treatment, therefore non-pharmacological rehabilitative approaches to such a symptom domain need to be identified. However, since not all patients with Schizophrenia exhibit the same cognitive impairment profile, individualized rehabilitative approaches should be set up.

OBJECTIVES

We explored the last five-year literature addressing the issue of cognitive dysfunction response to rehabilitative methodologies in Schizophrenia to identify possible predictors of response and individualized strategies to treat such a dysfunction.

CONCLUSION

A total of 76 studies were reviewed. Possible predictors of cognitive rehabilitation outcome were identified among patient-specific and approach-specific variables and a general overview of rehabilitative strategies used in the last five years has been depicted. Studies suggest the existence of multifaced and multi-domain variables that could significantly predict pro-cognitive effects of cognitive rehabilitation, which could also be useful for identifying individual-specific rehabilitation trajectories over time.An individualized rehabilitative approach to cognitive impairment in Schizophrenia is possible if taking into account both patient and approach specific predictors of outcomes.

Feasibility and tolerability of a cognitive remediation clinical service in first episode coordinated specialty care

AIM

Cognitive remediation is an evidence-based intervention targeting the common and disabling cognitive deficits in people with psychosis. Findings from efficacy studies and meta-analyses show that cognitive remediation produces medium to large effects on cognition in both chronic and first episode patients. However, clinical availability of this treatment remains scarce, reflecting a major gap between science and practice. Here we describe the development of a cognitive remediation programme in an outpatient first episode psychosis clinical service, and preliminary feasibility and acceptability outcomes.

METHODS

Based on evidence from efficacy trials and assessment within the clinic of perceived benefits and barriers, we developed a CR programme that involved both internet-based computer training exercises and a weekly in-person therapy group. Outcomes were assessed based on data from three consecutive 12-week group series. Feasibility outcomes included adoption, fill, cost, and utilization; tolerability outcomes were based on user survey and focus group feedback.

RESULTS

We found evidence of feasibility including good adoption, fill, utilization, and cost. We also found good tolerability and satisfaction based on feedback from a user survey and focus groups, with more than 80% of respondents reporting high overall satisfaction with the programme and subjective cognitive and functional improvements.

CONCLUSIONS

The present report provides preliminary evidence that cognitive remediation can be translated into real world clinical practice for first episode psychosis. Systematic evaluation of implementation and dissemination of cognitive remediation is needed, and has the potential to improve access to cognitive health interventions for people with psychosis.

Predictors of remission from the ultra-high risk state for psychosis

AIM

A significant proportion of individuals at Ultra-High Risk (UHR) for psychosis do not transition to manifest psychosis. Many non-transitioning UHR individuals do, however, display poor long-term outcomes such as persistence of attenuated psychotic symptoms. Evidence is scarce on which variables may predict a better clinical and functional prognosis such as remission from the UHR state.

METHODS

A total of 146 UHR individuals were enrolled in a randomized clinical trial (RCT), with this being analyses secondary to the RCT. Participants were assessed on multiple domains of symptoms, functioning, neuro- and social cognition. Regression analyses elucidated on the predictive power of these measures to remission from the UHR status (ie, not meeting UHR criteria) at 12-month follow-up.

RESULTS

Of the 91 UHR individuals attending 12-month follow-up, 33 (36%) exhibited remission from the UHR state. Regression analyses revealed baseline functioning to be a significant predictor of risk remission, and this was maintained when controlling for the effect of antipsychotic medication, gender and estimated IQ. The individuals with remission from the UHR state showed lower attenuated psychotic- and depressive symptoms along with better functioning at 12-month follow-up.

CONCLUSION

Our findings indicate functioning to be a contributor to the symptomatic recovery of UHR individuals, but a large amount of the variance on risk remission is, however, explained by other factors. Additionally, our findings suggest that UHR individuals with better functioning at ascertainment may present with a better clinical and functional prognosis, which may inform on the need for monitoring and intervention in this subgroup.

Exploring the role of age as a moderator of cognitive remediation for people with schizophrenia

BACKGROUND

While Cognitive Remediation (CR) is effective in reducing cognitive and functioning difficulties in people with schizophrenia, there is variability in treatment response. Previous research suggested that participants' age may be a significant moderator of CR response.

AIM

To examine the impact of participants' age on CR outcomes.

METHOD

Individual participant data were accessed from fourteen CR randomised controlled trials. We tested the moderating effect of participants' age on cognitive and functioning outcomes using multivariate linear models.

RESULTS

Data from 1084 people with a diagnosis of schizophrenia were considered. Participants had a mean age of 36.6 years (SD 11), with 11.6 years of education (SD 2.8), and an average duration of illness of 13.5 years (SD 10.7). Multivariate models showed that participants' age, when considered as a continuous variable, was not a significant moderator of treatment effect for cognitive and functioning outcomes. However, when participants were split by median age, younger participants showed higher gains in executive functions following CR compared to older participants (p=0.02).

CONCLUSION

These results suggest that participants' age does not moderate most CR outcomes. However, larger age differences may influence the effect of CR on executive function. This may suggest some adaptation of CR practice according to participants' age. These findings inform the CR personalisation agenda.

Can IQ moderate the response to cognitive remediation in people with schizophrenia?

BACKGROUND

IQ and IQ decline are considered risk factors for poor prognosis in people with a diagnosis of schizophrenia. However, it is still not clear if, at least in part, IQ and IQ decline influence long-term outcomes via a negative effect on interventions.

AIM

To identify whether current IQ, estimated premorbid IQ, or IQ decline moderate the response to cognitive remediation (CR).

METHOD

Individual participant data from twelve randomised controlled trials of CR were considered. Hierarchical and k-means analyses were carried out to identify different IQ clusters. The moderating effect of estimated premorbid IQ, current IQ, and different IQ clusters (preserved, deteriorated and compromised trajectories) on cognitive outcomes at post-therapy and follow-up were evaluated using multiple linear regression.

RESULTS

Data from 984 participants (CR = 544, control = 440) with schizophrenia and schizoaffective disorders were considered. The sample had a mean current IQ of 84.16 (SD 15.61) and estimated premorbid IQ of 95.82 (SD 10.63). Current IQ moderated working memory outcomes: people with higher IQ had larger working memory gains after therapy compared to those with a lower IQ. Those with a preserved IQ had better cognitive outcomes compared to either the deteriorated or compromised IQ groups, and those with a deteriorated IQ had better outcomes compared to those in the compromised IQ group.

CONCLUSION

Current IQ is a significant moderator of cognitive gains after CR. These findings highlight the need to evaluate whether therapy adaptations (e.g. offering more sessions) can attenuate this effect so that those with lower IQ may derive benefit similar to those with higher IQ.

Computerized cognitive remediation therapy, REHACOM, in first episode of schizophrenia: A randomized controlled trial

Patients with schizophrenia show cognitive impairments that have been linked to poor social functioning. Computerized cognitive remediation therapy has shown to be effective in improving both cognition and functioning in chronic schizophrenia, but relatively little is known about how these approaches improve cognition and functioning when applied to early stages of psychosis. Eighty-six participants with a first episode of psychosis, undergoing a specific program for early stages of schizophrenia, undertook either the REHACOM computerized cognitive remediation intervention (n = 36), or an active control condition (n = 50) consisting in 24 one-hour sessions addressed twice a week. Clinical features, cognition and functioning were assessed at baseline, post-treatment and six months after finishing the intervention. A significant progressive improvement in neurocognition and functioning was globally shown with no differences observed between the experimental and control group at post training or follow up. All cognitive domains but Social Cognition improved between 0.5 and 1 S.D. through the study period. The computerized cognitive remediation therapy REHACOM has not proved to be effective on improving cognition nor functioning compared to controls in outpatients with a first episode of schizophrenia.

Nicotine effects on cognitive remediation training outcome in people with schizophrenia: A pilot study

Cognitive remediation training can alleviate cognitive impairment associated with schizophrenia, but the impact is limited by small effect sizes. The present study aimed at augmenting training effects by administering nicotine prior to training sessions. Twenty-five people with schizophrenia were enrolled in a 10-week, 5 days/week, computerized cognitive training regimen. Participants were randomized to two treatment groups: nicotine or placebo. Every Monday and Thursday, the nicotine group received a nicotine lozenge before the training, and the placebo group a placebo lozenge. Outcome measurements were conducted on a no-lozenge day in weeks 0, 4, 7, and 10, and at 4-week follow-up. The MATRICS Consensus Cognitive Battery composite score improved over time, but there was no group difference in this effect. A significant group difference emerged over time in the reasoning/problem solving sub-domain: the placebo group improved but not the nicotine group, suggesting that nicotine exposure negatively impacted training benefits on executive control processes. There were no effects on psychiatric symptoms. However, significant improvements were seen across groups on the Quality of Life Scale and the Cognitive Assessment Interview, measuring real-life functional outcome. In conclusion, the present study failed to find evidence that nicotine exposure during cognitive remediation training may potentiate training benefits.

A systematic review of factors that influence the efficacy of cognitive remediation therapy in schizophrenia

OBJECTIVE

Cognitive remediation therapy is a moderately effective intervention for ameliorating cognitive deficits in individuals with schizophrenia-related disorders. With reports of considerable variability in individual response to cognitive remediation therapy, we need to better understand factors that influence cognitive remediation therapy efficacy to realise its potential. A systematic review was conducted to identify and evaluate predictors of cognitive outcome.

METHODS

An electronic database search was conducted identifying peer-reviewed articles examining predictors of cognitive response to cognitive remediation therapy.

RESULTS

A total of 40 articles accounting for 1681 cognitive remediation therapy participants were included; 81 distinct predictors of cognitive response were identified. Data synthesis and discussion focused on 20 predictors examined a minimum three times in different studies. Few of the examined predictors of cognitive outcome following cognitive remediation therapy were significant when examined through systematic review. A strong trend was found for baseline cognition, with reasoning and problem solving and working memory being strongly predictive of within-domain improvement. Training task progress was the most notable cross-domain predictor of cognitive outcome.

CONCLUSION

It remains unclear why a large proportion of participants fail to realise cognitive benefit from cognitive remediation therapy. However, when considering only those variables where a majority of articles reported a statistically significant association with cognitive response to cognitive remediation therapy, three stand out: premorbid IQ, baseline cognition and training task progress. Each of these relates in some way to an individual's capacity or potential for change. There is a need to consolidate investigation of potential predictors of response to cognitive remediation therapy, strengthening the evidence base through replication and collaboration.

What variables predict cognitive remediation associated improvement in individuals with psychosis?

On average, cognitive remediation (CR) is effective in improving cognitive function in individuals with psychosis, though there is considerable variability in treatment response. No consensus has emerged to date about the potential influence of patient and illness characteristics on CR efficacy. In the current analyses, we examined baseline demographic, cognitive, clinical, and functional ability variables as potential moderators of cognitive improvements during a randomized, controlled trial of a hybrid drill-and-practice plus strategy training CR intervention. In an attempt to disentangle non-specific vs. CR specific treatment effects, we separately examined potential predictors of cognitive improvement in individuals who received CR versus those in the control condition. Cognitive gains were predicted by a large array of demographic, symptom and cognitive variables, however this was true both in the CR and the control condition. CR-specific cognitive improvement was associated with more severe course of illness as indexed by higher number of hospitalizations, with poorer baseline cognition, and with less severe baseline negative symptoms.

The nuts and bolts of Cognitive Remediation: Exploring how different training components relate to cognitive and functional gains

BACKGROUND

Cognitive Remediation (CR) is an evidence based treatment targeting cognitive and functional difficulties in people with psychosis. Despite the large number of effectiveness studies, only limited evidence exists for the active ingredients of this therapy. This study begins to fill this gap by exploring the relationship between CR ingredients, including alliance with a therapist, and therapy outcomes.

METHOD

This is a secondary analysis based on data from a published randomised controlled trial comparing CR+treatment-as-usual (TAU) to TAU alone. We considered the association between CR active ingredients including errorless learning, massed practice, strategy use and therapeutic alliance on the cognitive, functioning and symptom outcomes that significantly improved following therapy.

RESULTS

Forty-six of the 96 participants were randomised to CR. After therapy the CR group showed significant improvement in non-verbal memory, functioning and approaching significance, improvements in executive functions. All therapy ingredients were inter-related but strategy use alone was associated therapeutic alliance. Cognitive improvements were associated with massed practice, number of useful strategies and therapeutic alliance, but improvements in functioning were associated only with therapeutic alliance.

CONCLUSIONS

These findings build the evidence base for the usefulness of specific therapy components. As for other psychological therapies it appears that therapeutic alliance may be an important factor in driving change for key CR outcomes, particularly functioning, in people with psychosis.

Cognitive training to improve memory in individuals undergoing electroconvulsive therapy: Negative findings

Although electroconvulsive therapy (ECT) remains the most effective treatment for severe depression, some patients report persistent memory problems following ECT that impact their quality of life and their willingness to consent to further ECT. While cognitive training has been shown to improve memory performance in various conditions, this approach has never been applied to help patients regain their memory after ECT. In a double-blind study, we tested the efficacy of a new cognitive training program called Memory Training for ECT (Mem-ECT), specifically designed to target anterograde and retrograde memory that can be compromised following ECT. Fifty-nine patients with treatment-resistant depression scheduled to undergo ultra-brief right unilateral ECT were randomly assigned to either: (a) Mem-ECT, (b) active control comprised of nonspecific mental stimulation, or (c) treatment as usual. Participants were evaluated within one week prior to the start of ECT and then again within 2 weeks following the last ECT session. All three groups improved in global function, quality of life, depression, and self-reported memory abilities without significant group differences. While there was a decline in verbal delayed recall and mental status, there was no decline in general retrograde memory or autobiographical memory in any of the groups, with no significant memory or clinical benefit for the Mem-ECT or active control conditions compared to treatment as usual. While we report negative findings, these results continue to promote the much needed discussion on developing effective strategies to minimize the adverse memory side effects of ECT, in hopes it will make ECT a better and more easily tolerated treatment for patients with severe depression who need this therapeutic option.