Summary: A University of Miami–led study funded by the Veterans Administration finds that the genetic patterns linked to cognition are largely similar in people with schizophrenia, people with bipolar disorder, and the general population. The result suggests shared genomic influences on cognitive performance and may guide broader assessment and treatment strategies for cognitive impairment.
Source: University of Miami
Major findings and significance
Researchers at the University of Miami Miller School of Medicine, together with Veterans Affairs collaborators, analyzed genomic and cognitive data from more than 9,000 U.S. veterans diagnosed with schizophrenia or bipolar disorder. Contrary to expectations that cognitive deficits in these severe mental illnesses (SMI) would reflect distinct genetic profiles, the study found substantial overlap between the genetics of cognition in these disorders and the genetics of cognition in the general population.
Lead author Philip D. Harvey, Ph.D., professor of psychiatry and behavioral sciences, emphasized that the strongest signal in the data was one of continuity rather than difference: the same genomic influences that shape cognition across the general population appear to drive much of the cognitive variation seen in schizophrenia and bipolar disorder. This finding reframes how researchers think about cognitive impairment in SMI and opens the door to more unified approaches to assessment and treatment.
Study design and methods
The research combined rigorous clinical evaluation with genomic analysis. Unlike large database-only studies, the team personally assessed every participant, confirming diagnoses and administering cognitive tests. The cohort included veterans with carefully validated diagnoses of schizophrenia or bipolar disorder, making this the largest mental health study to blend genome-wide association methods with direct cognitive testing.
Participants were genotyped on a custom array and the investigators performed a genome-wide association study (GWAS) focused on global cognitive functioning. They constructed polygenic scores for cognitive performance and for schizophrenia risk, and examined genetic correlations with thousands of traits cataloged in population datasets. While no single genetic locus reached genome-wide significance in this cohort, allelic effects aligned closely with previous findings from larger population studies. Polygenic scores for cognition and intelligence were strongly associated with better cognitive performance, whereas higher polygenic loading for schizophrenia risk correlated with poorer cognitive outcomes.
Implications for assessment and treatment
Because the genetic architecture and likely biological pathways for cognition show broad similarity across schizophrenia, bipolar disorder, and the general population, clinical assessment tools and therapeutic strategies proven effective in one setting may be more widely applicable than previously thought. Dr. Harvey suggests that clinicians may not need disorder-specific cognitive assessments or entirely different cognitive interventions for schizophrenia versus bipolar disorder; instead, differences in tests and treatments may need only to reflect severity and difficulty level rather than fundamentally different approaches.
This convergence of genomic findings also supports exploring targeted biological treatments, including gene-informed strategies, and encourages researchers to consider whether cognitive impairments in SMI represent an amplification of normal cognitive variation rather than wholly distinct processes.
Source:
University of Miami
Media Contacts:
Joanna Palmer – University of Miami
Image Source:
The image is in the public domain.
Original research: Closed access. Citation: “Genome‐wide association study of cognitive performance in U.S. veterans with schizophrenia or bipolar disorder,” Philip D. Harvey, Ph.D., et al., American Journal of Medical Genetics. DOI: 10.1002/ajmg.b.32775.
Abstract (restated)
Cognitive impairment frequently accompanies severe mental illnesses such as schizophrenia and bipolar disorder. Prior studies suggest genetic links to cognitive traits in both clinical groups and the general population. This study aimed to identify genomic signatures of cognitive performance in veterans with SMI and to compare those signatures with findings from broader population studies. The research genotyped thousands of veterans with schizophrenia or bipolar disorder and evaluated their cognitive and functional capacity. Although no single genetic locus reached genome-wide significance, the pattern of allelic effects was consistent with previous reports. Polygenic scores for cognitive performance and intelligence were robustly associated with better global cognitive functioning, and higher polygenic risk for schizophrenia correlated with poorer cognitive outcomes. The results demonstrate extensive overlap between the common genetic influences on cognition in the general population and those observed in veterans with schizophrenia or bipolar disorder.