Assessment of subjective and objective cognitive function in bipolar disorder: Correlations, predictors and the relation to psychosocial function Kirsa M. Demant, Maj Vinberg, Lars V. Kessing, Kamilla W. Miskowiak n Clinic for Affective Disorders, Psychiatric Centre Copenhagen, Copenhagen University Hospital, Rigshospitalet, Blegdamsvej 9, DK-2100 Copenhagen, Denmark article info Article history: Received 2 September 2014 Received in revised form 18 April 2015 Accepted 19 May 2015 Keywords: Cognition Self-report Memory Attention Executive function abstract Cognitive dysfunction is prevalent in bipolar disorder (BD). However, the evidence regarding the association between subjective cognitive complaints, objective cognitive performance and psychosocial function is sparse and inconsistent. Seventy seven patients with bipolar disorder who presented cognitive complaints underwent assessment of objective and subjective cognitive function and psychosocial functioning as part of their participation in two clinical trials. We investigated the association between global and domain-specific objective and subjective cognitive function and between global cognitive function and psychosocial function. We also identified clinical variables that predicted objective and subjective cognitive function and psychosocial functioning. There was a correlation between global subjective and objective measures of cognitive dysfunction but not within the individual cognitive domains. However, the correlation was weak, suggesting that cognitive complaints are not an assay of cognition per se. Self-rated psychosocial difficulties were associated with subjective (but not objective) cognitive impairment and both subjective cognitive and psychosocial difficulties were predicted by depressive symptoms. Our findings indicate that adequate assessment of cognition in the clinical treatment of BD and in drug trials targeting cognition requires implementation of not only subjective measures but also of objective neuropsychological tests. & 2015 Elsevier Ireland Ltd. All rights reserved. 1. Introduction Cognitive dysfunction is common in bipolar disorder (BD) and persists in remission suggesting that cognitive difficulties are trait- related and not merely dependent on mood (Martinez-Aran et al., 2004; Goldberg and Chengappa, 2009; Torrent et al., 2012). In particular, deficits are shown in verbal learning and memory, sus- tained attention and executive function (Torres et al., 2007; Bora et al., 2009; Bourne et al., 2013) and are important mediators of patients' reduced psychosocial and workforce functioning (Martinez-Aran et al., 2004; Martino et al., 2008; Torrent et al., 2012; Van Rheenen and Rossell, 2014). Consequently, cognitive difficulties in BD contribute to the substantial costs of BD both for the individual and for society. In our recent randomised negative trial on the effects of cognitive remediation on cognitive dysfunction in BD (the ‘REMEDI’ trial) (Demant et al., 2015 (in press)), post-hoc comparison of raw mean scores between baseline objective cognitive assessments and norma- tive data indicated no objective impairment ( o1 S.D. below norms) of sustained attention or executive function despite patients' moderate to severe cognitive complaints (Demant et al., 2015 (in press)). Verbal memory was generally within normal range in comparison with meta-norms, although a subgroup of 35% patients (n ¼ 14) showed impaired verbal memory performance ( 41 S.D. under the meta- norm). In another study from our group investigating the effects of erythropoietin (EPO) on cognitive dysfunction in BD (the ‘ EPO’ trial) we found that sustained attention, executive function and verbal memory performance were also within the normal range compared with norms despite patients' moderate to severe cognitive complaints (Miskowiak et al., 2014). This suggests that subjective and objective cognitive dysfunction in BD is poorly correlated which is consistent with the findings of other studies (Burdick et al., 2005; van der Werf- Eldering et al., 2011), including a study from our group (Svendsen et al., 2012). Nevertheless, there are also reports of the opposite (Martinez-Aran et al., 2005; Arts et al., 2011; Rosa et al., 2013). In particular, it was demonstrated that self-reported cognitive difficulties as measured with a new screening questionnaire (COBRA) correlated with objective performance deficits on some (but not all) tests of Contents lists available at ScienceDirect journal homepage: www.elsevier.com/locate/psychres Psychiatry Research http://dx.doi.org/10.1016/j.psychres.2015.05.022 0165-1781/& 2015 Elsevier Ireland Ltd. All rights reserved. n Corresponding author at: Psychiatric Centre Copenhagen, Copenhagen Univer- sity Hospital, Rigshospitalet, dep. 6233, Blegdamsvej 9, 2100 Copenhagen, Den- mark. Tel.: þ45 38647087. E-mail addresses: kirsa.moerkeberg.demant@regionh.dk (K.M. Demant), maj.vinberg@regionh.dk (M. Vinberg), lars.vedel.kessing@regionh.dk (L.V. Kessing), kamilla.woznica.miskowiak@regionh.dk (K.W. Miskowiak). Please cite this article as: Demant, K.M., et al., Assessment of subjective and objective cognitive function in bipolar disorder: Correlations, predictors and the.... 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