In a comprehensive review of recent genetic and population studies, published in the peer-reviewed medical journal Genomic Psychiatry (Genomic Press, New York), Professors Michael Owen and Michael O'Donovan of Cardiff University's Centre for Neuropsychiatric Genetics and Genomics present evidence that challenges conventional wisdom about cognitive deficits in schizophrenia. Their analysis reveals that premorbid cognitive impairment – lower IQ and other cognitive deficits present before the onset of psychosis – is largely explained by non-familial factors rather than by the same inherited genetic variants that increase risk for schizophrenia itself.
"For decades, we've assumed that premorbid cognitive problems in people with schizophrenia were directly caused by the same genetic factors that cause the disorder," said Professor Owen. "Our review of the latest research suggests this isn't the case. Instead, it appears that neurodevelopmental disruptions are responsible for both the cognitive deficits and the increased risk of developing schizophrenia."
Key findings from the review include:
The researchers propose a model in which neurodevelopmental perturbations, largely influenced by non-familial factors, lead to both cognitive impairment and increased vulnerability to schizophrenia. They also challenge the idea of a distinct "neurodevelopmental subtype" of schizophrenia, instead suggesting a spectrum of neurodevelopmental impairment across the disorder.
"These findings have important implications for how we think about schizophrenia and cognitive impairment," said Professor O'Donovan. "Understanding the causes of early neurodevelopmental disruptions will be important for developing interventions aimed at preventing or mitigating both the cognitive deficits and schizophrenia risk."
The research also highlights the need for further investigation into the causes of cognitive decline after schizophrenia onset, as well as the increased risk of dementia in this population. Understanding these processes could lead to new approaches for preserving cognitive function in individuals with schizophrenia throughout their lives.
This review represents a significant advance in our understanding of the complex interplay between genetics, cognition, and schizophrenia risk. It paves the way for more targeted research into the underlying mechanisms of cognitive impairment in schizophrenia and may ultimately inform the development of new prevention and treatment strategies.
The full review, titled “The genetics of cognition in schizophrenia,” was published on 16 July 2024 and is available online at the website of Genomic Psychiatry : https://gp.genomicpress.com/aop/ .
About Genomic Psychiatry – Genomic Psychiatry : Advancing Science from Genes to Society (ISSN: 2997-2388) represents a paradigm shift in genetics journals by interweaving advances in genomics and genetics with progress in all other areas of contemporary psychiatry. Genomic Psychiatry publishes peer-reviewed papers of the highest quality from any area within the continuum that goes from genes and molecules to neuroscience, clinical psychiatry, and public health.
Literature review
People
The genetics of cognition in schizophrenia
16-Jul-2024
M.J.O. and M.C.O. reported receiving grants from Akrivia Health and the Takeda Pharmaceutical Company Ltd outside the submitted work. Takeda and Akrivia played no part in the conception, design, implementation, or interpretation of this study.