Does cognitive improvement translate into functional changes? Exploring the transfer mechanisms of cognitive remediation therapy for euthymic people with bipolar disorder

Abstract

Background Bipolar disorder (BD) is associated with cognitive and functional difficulties, persistent beyond mood episodes. Cognitive remediation (CR) is a psychological therapy targeting cognitive and functioning difficulties. Recent evidence suggests that CR may enhance long-term functioning but transfer mechanisms on functional outcomes have not been explored. We aim to investigate whether and how cognitive gains after CR transfer to functional improvement. Methods We considered data from a randomized controlled trial comparing CR (n = 40) to treatment-as-usual (TAU; n = 40) in euthymic people with BD. Treatment outcomes included individual cognitive domains and global cognition, psychosocial functioning, and goal attainment. Regression-based mediation and moderation modelling were used to assess whether and how post-treatment cognitive changes translate into functional improvement at follow-up, three months after treatment end. Results Cognitive gains after CR transferred to functional changes three months later: improvement in post-treatment global cognition partially mediated the effect of CR on psychosocial functioning (standardized indirect effect: −0.23, 95% CI −0.51 to −0.04). Goal attainment was not significantly mediated by changes in cognition, but post-treatment cognitive performance moderated the effect of CR on the GAS at follow-up (interaction effect: 0.78, 95% CI 0.08–1.55). Conclusions Our findings suggest that cognitive improvements contribute to functional improvement but transfer mechanisms differ between psychosocial functioning and idiosyncratic recovery goals. Cognition accounted for only a proportion of the total CR effect on functional outcomes. Future studies should consider other variables, such as metacognition, that may drive the transfer of CR effects to functional outcomes.

Efficacy of cognitive remediation in bipolar disorder: systematic review and meta-analysis of randomized controlled trials

“…For the cognitive variables explored, most overall effects did not vary substantially when removing any of the studies from the synthesis except in two variables: planning and working memory at treatment completion. In the former, the removal of Ott et al (2021b) or Tsapekos et al (2023) rendered the observed effects nonsignificant, and similarly did the removal of either of two studies (Gomes et al, 2019;Lewandowski et al, 2017) in the latter variable. Interestingly, the removal of Douglas et al (2022), which is the only study including patients with different mood states and exploring a combination of psychological treatments, did not change the overall effects.…”

The Efects of Cognitive Remediation Therapy in Bipolar Disorder Patients

“…This suggested that functional difficulties can be reduced through improvements in cognition. 29 Tsapekos et al also found that CR largely improved goal attainment, especially BD with better baseline cognitive performance; severe baseline subjective cognitive, and completed psychological therapies; global cognition; and individual cognitive domains. Their other findings were medium effect size for global cognition, small-to-medium effect sizes for individual cognitive domains, and medium improvement in psychosocial functioning.…”

“…6 A statistically significant effect on the verbal memory was also found after 13 weeks of CR or 10 weeks of ABCR. 28,29 However, the effect was no longer significant at the 6 months follow-up and only the subjective cognitive function persists. 28 CR also could improve psychosocial function by engaging in real-world activities and navigating workplace situations, 14 and medium improvement were shown 31 .…”

“…27 For the attention domain, CR could improve attention at week 13 after ABCR, and CR that involved distinct cognitive operations training resulted in medium-to-large effects on processing speed after 25 weeks. 14,29 But another study showed that the ABCR didn't improve the speed of complex cognitive processing. 28 This difference may suggest that CR could give a better outcome on processing speed.…”

“…19 But these findings were contradictive with Ott et al, which found that ABCR was associated with an early dPFC activity increase. 29 compared to standard treatment. This was also the case for the functional outcomes (autonomy, occupation, cognition, financial issues, interpersonal relationships, leisure time).…”