Developing models of how cognitive improvements change functioning: Mediation, moderation and moderated mediation

Abstract

BackgroundCognitive remediation (CRT) affects functioning but the extent and type of cognitive improvements necessary are unknown.AimTo develop and test models of how cognitive improvement transfers to work behaviour using the data from a current service.MethodParticipants (N49) with a support worker and a paid or voluntary job were offered CRT in a Phase 2 single group design with three assessments: baseline, post therapy and follow-up. Working memory, cognitive flexibility, planning and work outcomes were assessed.ResultsThree models were tested (mediation — cognitive improvements drive functioning improvement; moderation — post treatment cognitive level affects the impact of CRT on functioning; moderated mediation — cognition drives functioning improvements only after a certain level is achieved). There was evidence of mediation (planning improvement associated with improved work quality). There was no evidence that cognitive flexibility (total Wisconsin Card Sorting Test errors) and working memory (Wechsler Adult Intelligence Scale III digit span) mediated work functioning despite significant effects. There was some evidence of moderated mediation for planning improvement if participants had poorer memory and/or made fewer WCST errors. The total CRT effect on work quality was d = 0.55, but the indirect (planning-mediated CRT effect) was d = 0.082ConclusionPlanning improvements led to better work quality but only accounted for a small proportion of the total effect on work outcome. Other specific and non-specific effects of CRT and the work programme are likely to account for some of the remaining effect. This is the first time complex models have been tested and future Phase 3 studies need to further test mediation and moderated mediation models.

Cognitive remediation improves memory and psychosocial functioning in first-episode psychiatric out-patients

“…Analyses were conducted using all available data excluding those from participants who did not meet entry criteria. Thus, an intent-to-treat (ITT) approach was adopted, assuming data were missing at random (MAR), including any significant predictors of drop-out as covariates, consistent with previous research (Wykes et al 2012). One-way ANOVAs were conducted to determine: (1) whether those who withdrew from the study were different from those who completed the study; and (2) whether any baseline variable differed between treatment conditions despite randomization.…”

Metacognition in Relation to Cognitive and Social Functioning in Schizophrenia

“…Metacognition as defined by Flavell (1979) contributes to the use of cognitive processes in everyday life (Wykes et al, 2012). Support comes from the finding that metacognition is an important factor in cognitive treatment, for example, in people with traumatic brain injury or stroke (Cicerone et al, 2011).…”

“…Metacognition is needed to reflect on cognitive processes and contributes to the way cognitive processes are used in everyday life, which directly affects social functioning (Cella et al, 2014;Green et al, 2000;Wykes et al, 2012). Metacognition has already been found to mediate the relationship between cognitive improvement following cognitive remediation and functional outcome (Wykes & Spaulding, 2011;Wykes et al, 2012).…”

“…Metacognition is needed to reflect on cognitive processes and contributes to the way cognitive processes are used in everyday life, which directly affects social functioning (Cella et al, 2014;Green et al, 2000;Wykes et al, 2012). Metacognition has already been found to mediate the relationship between cognitive improvement following cognitive remediation and functional outcome (Wykes & Spaulding, 2011;Wykes et al, 2012). In a study by Lysaker, Shea et al (2010), the effects of cognitive deficits (i.e., executive function, verbal and visual memory, processing speed, and verbal intelligence) on the quality and quantity of social relationships were mediated by the mastery aspect of metacognition, even after controlling for symptoms.…”

Treating impaired cognition in schizophrenia: The case for combining cognitive-enhancing drugs with cognitive remediation

“…The ultimate goal of addressing CIAS is to improve real-world functioning. The relationship between cognition and function in schizophrenia is robust but the way cognitive improvements change functioning is still an open question (Wykes et al, 2012). Nevertheless, meta-analytic evidence suggests that stronger effects on function are produced when cognitive remediation is added to other rehabilitation programs .…”