Evaluating how treatment adherence influences cognitive remediation outcomes.

BACKGROUND: There is evidence that Cognitive Remediation (CR) is an efficacious approach to reduce cognitive and functioning difficulties in people with schizophrenia. However, there is still a limited understanding of what influences different treatment responses. Treatment adherence has been suggested as one factor but has not been investigated systematically. AIM: To investigate how the number of CR sessions completed influences treatment outcomes. METHOD: This study used data from six randomised controlled trials comparing CR to a control condition. Instrumental variable analysis was used to evaluate the effect of number of treatment sessions on cognitive and functional outcomes. Logistic regression analysis was conducted to identify significant predictors of session attendance. RESULTS: A total of 440 participants with schizophrenia spectrum diagnosis were considered. Participants were mostly men (71.6%) and had a mean age of 39.6 (SD 10.69). A higher number of CR sessions led to larger improvements in executive function and processing speed at end of therapy. However, number of sessions did not influence outcomes for working memory and functioning. Younger age and higher levels of negative symptoms at baseline were associated with higher treatment attendance. CONCLUSION: These findings highlight the importance of treatment adherence and underscore the importance of massed practice, at least for some cognitive outcomes. While it may be complex to assess a single session's contribution to outcome in a dose-response fashion, accessing more sessions seems associated with some cognitive benefits. Observing a relationship to functioning may require longer therapy.

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.

Cognitive enhancement interventions for people with bipolar disorder: A systematic review of methodological quality, treatment approaches, and outcomes.

BACKGROUND: Patients with bipolar disorder (BD) suffer from cognitive deficits across several domains. The association between cognitive performance and psychosocial functioning has led to the emergence of cognition as a treatment target. OBJECTIVE: This study reviews the existing literature on cognitive enhancement interventions for people with BD, focusing on different treatment approaches and methodological quality. METHODS: We conducted a systematic search following the PRISMA guidelines. Sample characteristics and main outcomes for each study and treatment characteristics for each approach were extracted. Study quality was assessed using the Clinical Trials Assessment Measure (CTAM) and Cochrane Collaboration's Risk of Bias tool by independent raters. RESULTS: Eleven articles reporting data from seven original studies were identified encompassing 471 participants. Two treatment approaches were identified, cognitive and functional remediation. For controlled studies, methodological quality was modest (average CTAM score = 60.3), while the overall risk of bias was considered moderate. Beneficial effects on cognitive or functional outcomes were reported in the majority of studies (91%), but these findings were isolated and not replicated across studies. Key methodological limitations included small sample sizes, poor description of randomization process, high attrition rates, and participant exclusion from the analysis. CONCLUSIONS: Findings are promising but preliminary. Quality studies were few and mostly underpowered. Heterogeneity in sample characteristics, outcome measures, and treatment approaches further limit the ability to generalize findings. Adequately powered trials are required to replicate initial findings, while moderators of treatment response and mechanisms of transfer need to be explored.

A systematic review of moderators of cognitive remediation response for people with schizophrenia.

BACKGROUND: There is evidence that cognitive remediation (CR) is moderately effective in improving cognitive and functional difficulties in people with schizophrenia. However, there is still a limited understanding of what influence different treatment responses. AIM: To identify moderators influencing CR response in people with schizophrenia. METHODS: This systematic review follows PRISMA guidelines. Searches were conducted up to January 2019 on PubMed and PsychInfo to identify randomized controlled trials of CR reporting analyses of moderators of treatment response. All papers were assessed for methodological quality and information on sample size, intervention and control condition, moderators, outcomes, effect of moderator on outcomes and demographic characteristics from each study was extracted and critically summarised. RESULTS: Thirty-six studies were included, considering 2737 participants. Study participants consisted on average of people in their late-thirties, mostly men, with over 10 years of illness. The review identified moderators that could be grouped into five categories: demographics, biological, cognitive and functional, psychological, and illness-related characteristics. The assessment of methodological quality showed that many studies had a high risk of bias. CONCLUSIONS: There was no high-quality replicated evidence which identifies reliable moderators of CR response. Many moderators were not replicated or presented in single, underpowered studies. Studies also investigated moderators independently despite their potential to overlap (e.g. age and education). Future research should concentrate on evaluating, with sound studies, the role moderators may play in affecting CR treatment response. This information can inform who will benefit most from the therapy and help to improve the benefits of CR.