A meta-analytic investigation of neurocognitive deficits in bipolar illness: Profile and effects of clinical state.

Abstract

A meta-analysis of neuropsychological studies of patients with bipolar disorder in euthymic, manic/ mixed or depressed phases of illness was conducted. Measures of attention, working memory, verbal and non-verbal memory, visuospatial function, psychomotor speed, language, and executivefunction were evaluated in 42 studies of 1197 patients in euthymia, 13 studies consisting of 314 patients in a manic/mixed phase of illness, and 5 studies of 96 patients in a depressed state. Cohen d-values were calculated for each study as the mean difference between patient and control group score on each neuropsychological measure, expressed in pooled standard deviation units. Results for patients in euthymic, depressed and manic/mixed phases were evaluated separately and then a subset of measures on which patients in all three phases were tested were compared. For euthymia, results revealed impairment across all neuropsychological domains, with d-values in the moderate-large range (d=.5-.8) for the vast majority of measures. There was evidence of large effect-size impairment on measures of verbal learning (d=.81), and delayed verbal and non-verbal memory (d=.80-.92), while effect-size impairment on measures of visuospatial function was small-to-moderate (d≤.55). Patients tested during a manic/mixed or depressed phase of illness showed exaggerated impairment on measures of verbal learning, while patients tested during a depressed phase showed greater decrement on measures of phonemic fluency. Consistent with previous meta-analyses (Arts et al, 2007; Bora et al., 2009; Robinson et al., 2007), these results suggest that bipolar illness during euthymia is characterized by generalized moderate level impairment across an array of neurocognitive domains, with particular marked impairment in verbal learning and memory. These results also show that a subset of these deficits moderately worsen during acute disease states. Keywords bipolar illness; neurocognition; mania; depression; euthymia Over the past 10-15 years a growing number of studies have revealed that individuals with bipolar illness show deficits on standardized neuropsychological measures with particularly marked deficits in executive-function and verbal learning (see Arts et al, 2007; Bora et al., 2009;Robinson et al., 2006). Particular significance has been attached to these deficits as they have been linked to the intensity of the disease process (e.g., Denicoff et al., 1999;Ferrier et al., 1999), are persistent despite psychiatric symptom reduction (e.g., Joffe et al. 1998) and Correspondence regarding this article should be addressed to: Matthew M. Kurtz, Ph.D., Department of Psychology, Judd Hall, Wesleyan University, Middletown, CT. 06459; mkurtz@wesleyan.edu. Publisher's Disclaimer: The following manuscript is the final accepted manuscript. It has not been subjected to the final copyediting, fact-checking, and proofreading required for formal publication. It is not the definitive, publisher-authenticated version. The American Psychological Association an...

Canadian Network for Mood and Anxiety Treatments (CANMAT) and International Society for Bipolar Disorders (ISBD) collaborative update of CANMAT guidelines for the management of patients with bipolar disorder: update 2013

“…In addition, patients tested during a manic ⁄ mixed or depressed state showed exaggerated impairment on measures of verbal learning (383).…”

“…Cognitive impairment: Three meta-analyses have demonstrated persistent cognitive impairments in euthymic patients with BD, including deficits in executive functions, verbal memory, learning, processing speed, and attention (357,382,383).…”

Persistence of cognitive impairment and its negative impact on psychosocial functioning in lithium-treated, euthymic bipolar patients: a 6-year follow-up study

“…By contrast, there were main effects of group in the executive domain (TMT-B and digit span backward), in the inhibition domain (Stroop inhibition), in the processing speed domain (TMT-A and hit reaction time of CPT-II), and finally in the verbal memory domain (immediate and delayed recall). Since previous studies (Clark et al 2002 ;Martínez-Arán et al 2004a ;Savitz et al 2005 ;Kurtz & Gerraty, 2009) have already established the impact of residual mood symptoms, a repeated-measures MANCOVA was also performed, controlling for pre-morbid IQ and by YMRS and HAMD score. Even including these covariates, the results showed again the same effects, except for the interaction in the hit reaction time of CPT-II (although it depicted a similar trend), which did not reach the significance threshold.…”

Differential Effects of Executive Functioning on Suicide Attempts

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