Clustering of cognitive subtypes in schizophrenia patients and their siblings: relationship with regional brain volumes

Abstract

Schizophrenia patients (SZH) often show impaired cognition and reduced brain structural volumes; these deficits are also detectable in healthy relatives of SZH. However, there is considerable heterogeneity: a sizable percentage of SZH are relatively cognitively intact; clustering strategies have proved useful for categorising into cognitive subgroups. We used a clustering strategy to investigate relationships between subgroup assignment and brain volumes, in 102 SZH (N = 102) and 32 siblings of SZH (SZH-SIB), alongside 92 controls (CON) and 48 of their siblings. SZH had poorer performance in all cognitive domains, and smaller brain volumes within prefrontal and temporal regions compared to controls. We identified three distinct cognitive clusters (‘neuropsychologically normal’, ‘intermediate’, ‘cognitively impaired’) based on age- and gender-adjusted cognitive domain scores. The majority of SZH (60.8%) were assigned to the cognitively impaired cluster, while the majority of SZH-SIB (65.6%) were placed in the intermediate cluster. Greater right middle temporal volume distinguished the normal cluster from the more impaired clusters. Importantly, the observed brain volume differences between SZH and controls disappeared after adjustment for cluster assignment. This suggests an intimate link between cognitive performance levels and regional brain volume differences in SZH. This highlights the importance of accounting for heterogeneity in cognitive performance within SZH populations when attempting to characterise the brain structural abnormalities associated with the disease.

Beyond average outcomes: A latent profile analysis of diverse developmental trajectories in prematurely-born children from the ABCD study

“…This limitation hinders progress in pinpointing potential risk for long-term developmental deficits, the implementation of appropriate interventions, and the understanding of underlying mechanisms of these deficits. In the era of precision psychiatry, cluster approaches have enhanced understanding of major psychological disorders, such as schizophrenia, opening avenues for more precise treatment options (Alkan & Evans, 2022;Habtewold et al, 2020;L. Ji et al, 2020).…”

Cognitive Remediation in Psychiatric Disorders: State of the Evidence, Future Perspectives, and Some Bold Ideas

“…However, there is significant heterogeneity in cognitive impairment in schizophrenia and other psychoses. Most studies that have attempted to cluster cognitive subtypes in schizophrenia [ 20 , 21 , 22 ] report three distinct groups. While a smaller group of up to 25% of people with schizophrenia show relatively unimpaired cognitive functioning, a group with intermediate deficits (up to 40%) and a severely impaired group showing global deficits and increased negative symptomatology (up to 60%) could be identified.…”