New study investigating the impact of Schizophrenia on physical illness

Individuals with schizophrenia are at higher risk of physical illnesses, which are a major contributor to their 20-year reduced life expectancy. It is currently unknown what causes the increased risk of physical illness in schizophrenia.

In this study, colleagues at the MRC Centre for Neuropsychiatric Genetics and Genomics and SAIL Databank, Swansea University linked genetic data for 896 individuals with schizophrenia to anonymised NHS records.

Professor James Walters, Dr Kimberley Kendall and Dr Sophie Legge have published their findings in their paper ‘Impact of Schizophrenia and physical illness: data-linkage study.’ 

The aims of the study were to assess the rates of physical illness in those with schizophrenia and establish whether physical illness in schizophrenia is associated with genetic liability, through linking genetic data from a clinically ascertained sample of individuals with schizophrenia to anonymised National Health Service (NHS) records.

The results showed that those with schizophrenia had increased rates of epilepsy, intellectual disability, type 2 diabetes, congenital disorders, ischaemic heart disease and smoking.

There was no significant evidence found of increased rates of poor physical health outcomes in carriers of rare neurodevelopmental copy number variants (CNVs), however CNV carrier status was associated with height.

Dr Kendall said “We found no evidence for an association between schizophrenia and physical health outcomes. This lack of association remained in sensitivity analyses covarying for symptom severity, non-response to antipsychotics, antipsychotic exposure, smoking status & genotyping array. However, significant associations were identified between non-response to antipsychotics and type 2 diabetes and between symptom severity and intellectual disability.”

The study demonstrates the value of and potential for linking genetic data from clinically ascertained research studies to anonymised health records and concluded that the increased risk for physical illness in schizophrenia is not caused by genetic liability for the disorder.

The study was funded the Medical Research Council, the Wellcome Trust, MQ mental health research, and Health and Care Research Wales.

To read the full paper: ‘Impact of Schizophrenia and physical illness: data-linkage study.’