Neurocognitive heterogeneity in patients with bipolar disorder and their unaffected relatives: associations with emotional cognition.

Abstract

Recent evidence suggests that neurocognitive impairments in remitted patients with bipolar disorder (BD) are heterogeneous. Our study aims to replicate recent findings of neurocognitive subgroups, and further explore whether these are related to impairments in affective cognition, in a large sample of remitted patients recently diagnosed with BD and their unaffected relatives compared to healthy controls (HCs). Hierarchal cluster analysis was conducted using neurocognitive data from remitted patients with BD (n = 158). Relatives of patients with BD (n = 52) were categorised into groups consistent with their affected relative's cluster assignment. The neurocognitive clusters of patients with BD and relatives, respectively, were compared with HCs (n = 110) in neurocognition and affective cognition (i.e. emotion processing and regulation). Three discrete neurocognitive clusters were identified in patients with BD: a globally impaired (23.4%), a selectively impaired (31.0%) and a cognitively intact cluster (45.6%). The neurocognitive subgroups differed in affective cognition, with patients categorised as globally impaired exhibited most impairments in facial expression recognition and emotion regulation in social scenarios. First-degree relatives of cognitively impaired patients displayed impaired facial expression recognition but no impairments in non-emotional cognition. In a clinical sample of remitted patients recently diagnosed with BD 54.4% had either global or selective cognitive impairment, replicating results of previous studies in patients with longer illness duration. The results suggest that patterns of neurocognition are associated with differential impairments in affective cognition. Aberrant affective cognition in relatives of patients categorised as neurocognitively impaired indicates an inherited risk for BD.