People living with severe mental illness already face huge health inequalities. Now, new research led by MQ researcher Dr Amy Ronaldson shows that this group is also significantly more likely to die from common infections.
Dr Amy Ronaldson is one of MQ’s 2023 Fellows and is based at Kings College London. Amy’s work is focused on understanding why people with severe mental illnesses are more likely to die from infectious disease than the general population.
Amy’s study, published in Schizophrenia Bulletin, analysed national primary care data from across England to better understand how infection-related deaths affect people with severe mental illness (SMI), including conditions such as schizophrenia and bipolar disorder.
What did the study look at?
Amy and her team followed over 160,000 people, including more than 84,000 individuals with SMI, and compared them with a matched group without these conditions. The team examined deaths linked to infections over nearly two decades, from 2000 to 2019.
Importantly, the study used primary care data, meaning it captured a broader and more representative picture of people with SMI than previous research, which often focused on those receiving specialist mental health services.
A higher risk of dying from infection
Amy found that people with severe mental illness had a 58 percent higher risk of dying from an infection compared to those without SMI.
The risk was not the same across all infections. The study found a particularly increased risk of death from:
- Respiratory infections, such as pneumonia and influenza
- Gastrointestinal infections
- Kidney and urinary tract infections
These differences were seen even after accounting for factors like smoking, body mass index, deprivation, and other health conditions.
Why might this be happening?
The study highlights several possible explanations.
Some are linked to physical health. People with SMI are more likely to have other long-term conditions and lifestyle risk factors that increase vulnerability to infections.
But the picture is more complex. The research also points to:
- Barriers to accessing healthcare and delays in treatment
- Stigma and “diagnostic overshadowing”, where physical symptoms are misattributed to mental illness
- Biological changes, including differences in immune response
- Possible effects of some medications, particularly antipsychotics
Together, these factors may increase both the likelihood of infection and the risk of poorer outcomes once someone becomes unwell.