Cognitive remediation therapy for patients with bipolar disorder: A randomised proof-of-concept trial.

Rebecca Strawbridge,Allan H Young,Janet Boadu,Tim Mantingh,Dimosthenis Tsapekos,Paul Mccrone,Karine Macritchie,Jessica Fish,John Hodsoll,Matteo Cella,Til Wykes,Clare Reeder,Nefize Yalin

doi:10.1111/bdi.12968

Abstract

Cognitive remediation therapy (CRT) may benefit people with bipolar disorder type I and II for whom cognitive impairment is a major contributor to disability. Extensive research has demonstrated CRT to improve cognition and psychosocial functioning in people with different diagnoses, but randomised trials of evidenced therapy programmes are lacking for bipolar disorders. The Cognitive Remediation in Bipolar (CRiB) study aimed to determine whether an established CRT programme is feasible and acceptable for people with bipolar disorders. This proof-of-concept, single-blind randomised trial recruited participants aged 18-65 with bipolar disorder, not currently experiencing an episode. They were 1:1 block randomised to treatment-as-usual (TAU) with or without individual CRT for 12weeks. The partly computerised CRT programme ("CIRCuiTS") was therapist-led and is evidence-based from trials in those with psychotic illnesses. Data were collected and analysed by investigators blinded to group allocation. The main outcomes (week 13 and 25) examined participant retention, intervention feasibility and putative effects of CRT on cognitive and psychosocial functioning via intention-to-treat analyses. ISRCTN ID32290525. Sixty participants were recruited (02/2016-06/2018) and randomised to CRT (n=29) or TAU (n=31). Trial withdrawals were equivalent (CRT n=2/29; TAU n=5/31). CRT satisfaction indicated high acceptability. Intention-to-treat analyses (N=60) demonstrated greater improvements for CRT- than TAU-randomised participants: at both week 13 and 25, CIRCuiTS participants showed larger improvements in the following domains (week 25 effect sizes reported here): IQ (SES=0.71, 95% CI [0.29,1.13]), working memory (SES=0.70, 95% CI [0.31,1.10]), executive function (SES=0.93, 95% CI [0.33,1.54]), psychosocial functioning (SES=0.49, 95% CI [0.18,0.80]) and goal attainment (SES=2.02, 95% CI [0.89,3.14]). No serious adverse events were reported. CRT is feasible for individuals with bipolar disorders and may enhance cognition and functioning. The reported effect sizes from this proof-of-concept trial encourage further investigation in a definitive trial.

Highlights

Cognitive remediation therapy (CRT) is feasible for individuals with bipolar disorders and may enhance cognition and functioning
Cognitive Remediation Therapy (CRT) is a psychological intervention that has demonstrated reliable benefits for people with schizophrenia, improving core cognitive functioning, daily functioning, and quality-of-life as determined through extensive examination via clinical trials and comprehensive meta-analytic syntheses.eg[5,6,7] There are well-documented similarities between the cognitive difficulties experienced by people with schizophrenia and bipolar disorder: they appear comparable in terms of impact and quality, are on average less severe for patients with Bipolar disorder (BD) than schizophrenia and there is less evidence of a premorbid component.[8]
Achieving adequate power relies on the feasibility of meeting recruitment targets by identifying sufficient participants who are eligible and willing to consent, the number of patients engaged with intervention and completing the trial (CRiB being equivalent or better compared to previous similar studies[9,14,34] with its 12% loss to follow-up rate and high therapy completion rate) between the number of required sites