Cognitive Performance in Schizophrenia & Bipolar Disorder & their First-Degree Relatives

Tran, Miribel

Due to the several notable similarities in symptoms between bipolar disorder (BD) and schizophrenia (SZ), it can be difficult to effectively distinguish and diagnose between these two illnesses. Neurocognitive performance may be able to serve as a potential trait marker for SZ and BD and can suggest the degree of genetic liability with their first-degree relatives. The objective of the current study was to examine differences in cognitive performance among control, SZ and BD patient groups, and their first-degree relatives and determine the degree of the genetic liability of BD and SZ with their first-degree relatives using neurocognitive performance scores. Using post-hoc statistical comparisons in cognitive tasks, significant differences were observed among the groups, suggesting the ability of cognitive performance to serve as a trait marker with predictive value. With further specificity, significant differences between cognitive domains in subtypes of SZ and BD were also found. As expected, controls displayed the least cognitive deficits compared to SZ, BD, and their first-degree relatives. SZ patients with schizoaffective disorder (SAD) showed the highest level of cognitive impairment in all neurocognitive domains. SZ showed higher cognitive impairment than BD in the domains of attention, visual memory, executive functioning, short memory, and perceptual motor skills. However, patients with SZ displayed better cognitive function than BD in immediate memory, delayed memory, and language. Using this quantitative and specific approach, psychiatrists can better diagnose SZ & BD patients and thus, increase the efficacy of medication and treatment.