Executive dysfunction in schizophrenia: Predictors of the discrepancy between subjective and objective measures

The Discrepancy between Subjective and Objective Evaluations of Cognitive and Functional Ability among People with Schizophrenia: A Systematic Review

BACKGROUND

An important aspect of recovery in schizophrenia relates to one's subjective, lived experience. Self-report is a subjective measurement method with yet-uncertain utility in the assessment of functioning among individuals diagnosed with schizophrenia-spectrum disorder. No review to date has comprehensively synthesized existing research to evaluate the degree of correspondence, or lack thereof, between subjective and objective assessments of cognitive and everyday functioning, nor how extant data can inform the use of self-reported information in treatment and research.

METHODS

A systematic review was completed to provide a broad perspective of the literature on this topic. Relevant manuscripts were identified via a search strategy using key terms in PubMed and PsycINFO and a review of manuscript bibliographies. Twenty-six studies met the inclusion criteria.

RESULTS

These studies show minimal to modest associations between subjective assessments of cognition and everyday functioning and objective assessments of these domains, including informant reports and neuropsychological and behavioral measures. Individuals with schizophrenia appear to overestimate their functioning when compared to objective measures. Depression and greater cognitive ability tend to predict greater correspondence between subjective and objective assessments of cognition and everyday functioning.

DISCUSSION

This review discusses how we might understand the low correspondence between subjective and objective measures of functioning and provides recommendations for using and eliciting self-reported information in the pursuit of recovery-centered practices.

Cognitive impairment in schizophrenia: aetiology, pathophysiology, and treatment

Cognitive deficits are a core feature of schizophrenia, account for much of the impaired functioning associated with the disorder and are not responsive to existing treatments. In this review, we first describe the clinical presentation and natural history of these deficits. We then consider aetiological factors, highlighting how a range of similar genetic and environmental factors are associated with both cognitive function and schizophrenia. We then review the pathophysiological mechanisms thought to underlie cognitive symptoms, including the role of dopamine, cholinergic signalling and the balance between GABAergic interneurons and glutamatergic pyramidal cells. Finally, we review the clinical management of cognitive impairments and candidate novel treatments.

Occupational intervention in mental health hospitals: Study of contextual impact

BACKGROUND

Recovery-promoting and occupation-oriented interventions for people with schizophrenia who receive in-patient services are scarcely investigated, limiting our understanding of the factors affecting intervention effectiveness and hindering occupational inclusion.

AIMS

To investigate the impact of contextual factors on the effectiveness of 'Occupational Connections' (OC) - occupational intervention for in-patient psychiatric settings.

MATERIALS AND METHODS

Quasi-experimental, single-blind study compared between inpatients with schizophrenia participating in OC (N = 14) and those receiving treatment as usual only (N = 16) on primary outcomes of participation dimensions and recovery-orientation of the service, and on secondary outcomes of cognition, symptom severity, and functional capacity.

RESULTS

Participation in OC in a new context appears to contribute to improvement in cognitive fluency and flexibility, schizophrenia symptoms, and functional capacity (-2.8<t < 4.32, p < 0.05) with no improvement in the participation dimensions (-1.36<t < 1.36, p > 0.05) or reduction (-2.25<t < 3.74, p < 0.05). The pattern of change in primary and secondary outcomes in a new context was distinct from previous reports on OC effectiveness.

CONCLUSIONS AND SIGNIFICANCE

These findings suggest the impact of contextual factors on OC effectiveness. Personal participants' factors, institutional features, clinician characteristics, and intervention qualities should be considered in the process of the OC further development, evidence building, and clinical implementation to ensure optimal intervention results.

Moderators of metacognitive strategy training for executive functioning in early schizophrenia and psychosis risk

Goal Management Training (GMT) improved self-reported executive functioning in a recent randomized, controlled trial in early intervention for psychosis participants. Little is known about the mechanism for this benefit, so this study investigates objectively measured executive function, the difference between subjective and objective executive function, independent living and employment status as potential moderators of efficacy of GMT.

Baseline scores from 81 participants (GMT n = 39 vs Treatment-as-usual; TAU n = 42) were analyzed in a linear mixed model analysis for repeated measures as predictors of improvement on the self-reported Behavior Rating Inventory of Executive Function–Adult version (BRIEF-A) immediately and 30 weeks after GMT. Potential moderators were scores from objective measures of executive functioning, discrepancy between subjective and objective measures, independent living and employment status. Discrepancy was assessed by comparing four clusters of participants with differing patterns of scores.

The effect of GMT remained significant regardless of initial objective executive functioning at baseline. Those with higher subjective complaints at baseline in two clusters with (i) both objective and subjective executive dysfunction, and (ii) mostly subjective executive dysfunction experienced greater change after treatment. Living arrangements or participation in education or work did not significantly moderate the effects of GMT.

Poor performance on neuropsychological tasks is not an obstacle to making use of GMT, but further knowledge is needed about the benefits of strategy training for individuals with a combination of poor performance with few subjective complaints.

A randomized controlled trial of Goal Management Training for executive functioning in schizophrenia spectrum disorders or psychosis risk syndromes

BACKGROUND

Executive functioning is essential to daily life and severely impaired in schizophrenia and psychosis risk syndromes. Goal Management Training (GMT) is a theoretically founded, empirically supported, metacognitive strategy training program designed to improve executive functioning.

METHODS

A randomized controlled parallel group trial compared GMT with treatment as usual among 81 participants (GMT, n = 39 versus Wait List Controls, n = 42) recruited from an early intervention for psychosis setting. Computer generated random allocation was performed by someone independent from the study team and raters post-intervention were unaware of allocation. The primary objective was to assess the impact of GMT administered in small groups for 5 weeks on executive functioning. The secondary objective was to explore the potential of the intervention in influencing daily life functioning and clinical symptoms.

RESULTS

GMT improved self-reported executive functioning, measured with the Behavior Rating Inventory of Executive Function - Adult version (BRIEF-A), significantly more than treatment as usual. A linear mixed model for repeated measures, including all partial data according to the principle of intention to treat, showed a significant group x time interaction effect assessed immediately after intervention (post-test) and 6 months after intervention (follow-up), F = 8.40, p .005, r .37. Improvement occurred in both groups in objective executive functioning as measured by neuropsychological tests, functional capacity, daily life functioning and symptoms of psychosis rated by clinicians. Self-reported clinical symptoms measured with the Symptoms Check List (SCL-10) improved significantly more after GMT than after treatment as usual, F = 5.78, p .019, r .29. Two participants withdrew due to strenuous testing and one due to adverse effects.

CONCLUSIONS

GMT had clinically reliable and lasting effects on subjective executive function. The intervention is a valuable addition to available treatment with considerable gains at low cost.

TRIAL REGISTRATION

Registered at clinicaltrials.gov NCT03048695 09/02/2017.