Neurocognitive functioning in individuals with bipolar disorder and their healthy siblings: A preliminary study

Abstract

Background Cognitive deficits have been consistently reported in individuals with bipolar disorder (BD). The cognitive profile of siblings of individuals with BD is, however, less clearly established possibly due to the heterogeneity of neuropsychological measures used in previous studies. The aim of this exploratory study was to assess the cognitive function of siblings of individuals with BD and compare it with that of their first-degree relatives suffering with BD, and healthy controls (HC) using the Cambridge Neuropsychological Test Automated Battery (CANTAB) - a comprehensive and validated computerized cognitive battery. Methods We recruited 23 HC (33.52±10.29 years, 8 males), 27 individuals with BD (34.26±10.19 years, 9 males, 25 BDI, 1BDII and 1 BD-NOS), and 15 of their biologically related siblings (37.47±13.15 years, 4 males). Siblings had no current or lifetime history of mental disorders. Participants performed the CANTAB and completed questionnaires assessing mood and global functioning. Multivariate analyses compared CANTAB measures across the three participant groups. Results Individuals with BD and their siblings were less accurate in a task of sustained attention (Rapid Visual Processing) when compared to HC. Further, individuals with BD displayed pronounced deficits in affective processing (Affective Go/No-Go) compared to HC. There were no cognitive differences between siblings and individuals with BD. After correcting for current depressive symptoms, these results did not reach statistical significance. Conclusions Subthreshold depressive symptoms may be associated with reduced sustained attention in healthy siblings of BD patients. This preliminary result needs to be corroborated by large-scale, longitudinal studies assessing the relationship between cognition and mood in vulnerable individuals.

Neurocognitive performance as an endophenotype for mood disorder subgroups

“…The enhanced function in some of the domains in our sample differs from the deficits that characterize most earlier work on BPD (Bauer et al, 2016; Cardenas et al, 2016; Lee et al, 2014; Sharma et al, 2016), and may reflect findings from earlier studies that people with BPD may actually have superior functioning in some cognitive domains, and higher IQ, school performance, and social functioning prior to onset of BPD (Demjaha et al, 2012), even in childhood (Cannon et al, 2002; Koenen et al, 2009; MacCabe et al, 2010). Of particular relevance to our study, the line orientation task has been shown to index greater functional life skills performance (for basic financial tasks) (Allen et al, 2015), so our finding of greater accuracy in visuospatial function could actually have broader functional implications.…”

Cognitive abilities in first-degree relatives of individuals with bipolar disorder

“…Although the study of cognition in relatives of individuals with BD is not new, findings in this group are still somewhat inconsistent (Balanza-Martinez et al, 2008;Cardenas et al, 2016;Hasler et al, 2006). For example, current work suggests that endophenotypic markers of genetic vulnerability for BD may be represented by deficits in verbal memory (Arts et al, 2008;Balanza-Martinez et al, 2008;Cardenas et al, 2016;Kieseppä et al, 2005;Kulkarni et al, 2010;McIntosh et al, 2005) and selective deficits in aspects of executive function and sustained attention (Arts et al, 2008;Bauer et al, 2016;Bora et al, 2008;Clark et al, 2005b;Ferrier et al, 2004a;Glahn et al, 2004;Nehra et al, 2006;Trivedi et al, 2008;Zalla et al, 2004), since FDRs have shown impairments on these domains relative to HCs. Speed of processing and verbal working memory deficits also seem to be related to genetic risk for BD, yet results on these domains are mixed, with some studies evidencing deficits in FDRs and others not (Antila et al, 2007b;Cardenas et al, 2016;Daban et al, 2012;Nehra et al, 2006;Pierson et al, 2000).…”

Intellectual Functioning in Offspring of Parents with Bipolar Disorder: A Review of the Literature

“…Our conclusions are largely consistent with other family risk studies that employed broader inclusion criteria (e.g., studies that include in their risk group a range of first-degree relatives like siblings, parents, and offspring). Using this broader inclusion criteria, there were several studies that failed to find FSIQ differences between patients with bipolar disorder, their first-degree relatives, and healthy controls [ 61 , 62 , 63 , 64 , 65 , 66 ], with some noted exceptions showing lower FSIQ in relatives of patients with BD (e.g., [ 67 , 68 ]. There were several family risk studies that also found lower PIQ or a larger discrepancy between VIQ and PIQ for those at family risk for BD (e.g., [ 64 , 68 ].…”