News · Brain & Mental Health
Severe mental illness carries 2.6 times the death rate
A Lancet Public Health study of 4.86 million people across five European countries found heart disease drives the most excess deaths in severe mental illness, but lung disease shows the widest gap.
Based on a peer-reviewed multi-country cohort study in The Lancet Public Health
- Researchers used national health registers in Denmark, Finland, France, Poland and Sweden, covering 4,861,795 people diagnosed with severe mental illness between 2004 and 2023, in The Lancet Public Health.
- Severe mental illness here means schizophrenia spectrum disorders, bipolar disorder or major depressive disorder.
- All-cause mortality was 2.64 times that of the general population (95% CI, 2.25-3.11).
- The largest number of excess deaths came from cardiovascular disease, at 22.08 extra deaths per 10,000 person-years in schizophrenia spectrum disorders.
- The widest relative gap was in respiratory disease: 6.49 times the expected rate in schizophrenia spectrum disorders.
- Endocrine, metabolic and gastrointestinal diseases also showed large relative excesses.
- These are physical illnesses, not suicide. The gap is largely about bodies, not psychiatric crisis.
- Register data reflect diagnosis and coding practice, and five countries with strong health systems may understate the gap elsewhere.
People with severe mental illness die around fifteen to twenty years early, and the assumption that this is mostly about suicide has proved durable and wrong. A study in The Lancet Public Health traced where the deaths actually come from, across five countries and nearly five million people.
All-cause mortality was 2.6-fold higher in people with severe mental illness compared with the general population. The causes were ordinary physical diseases.
Why the breakdown mattered
The gap itself has been documented for decades. Until now what had not been mapped carefully is which illnesses drive it, and that gap shapes where money goes.
The authors state the problem directly: how specific physical illnesses differentially contribute to the persistent mortality gap in severe mental illness remains poorly understood. Their aim was to identify high-burden and high-inequity mortality patterns to inform public health prioritisation and organization of care.
Five registers, twenty years
The design leans on something only a handful of countries can offer. Using national health registers, the team identified people diagnosed with severe mental illness at age 15-65 years in five European countries, Denmark, Finland, France, Poland, and Sweden, during 2004-23.
Severe mental illness was defined to include schizophrenia spectrum disorders, bipolar disorder, and major depressive disorder. Between January 2004 and December 2023 there were 4 861 795 people with severe mental illness, and 561 903 deaths from any cause.
Deaths were compared against each country’s own general population, then pooled.
Two different answers to “what matters most”
This is where the study earns its keep, because the ranking flips depending on how you ask.
By sheer numbers, the heart wins. Absolute excess mortality was highest in cardiovascular disease, running at about 22 extra deaths per 10,000 person-years in people with schizophrenia spectrum disorders.
By ratio, the lungs win. Relative excess mortality was highest in respiratory diseases, at roughly six and a half times the expected rate in schizophrenia spectrum disorders. Endocrine and metabolic diseases followed, then gastrointestinal diseases.
So cardiovascular disease kills the most people, while respiratory disease represents the sharpest inequality. Those point at different interventions, and a health system chasing only one measure would miss the other.
What the study does not claim
This is register-based observational work. It maps where deaths occur; it does not establish why, and it tests no intervention.
Registers also record what clinicians coded. Diagnostic overshadowing, where physical complaints in a psychiatric patient are attributed to the mental illness, would tend to distort exactly this kind of data.
And the five countries are unusually well served, with universal healthcare and mature registers. If anything that makes these figures a floor rather than a ceiling for the rest of the world.
The authors’ conclusion is about method as much as findings: considering both dimensions of excess mortality can inform public health priorities that are not apparent from either measure alone.
The practical version is blunt. A psychiatric diagnosis should trigger physical health monitoring, because the thing most likely to kill these patients is the same thing most likely to kill everyone else, only sooner.
People also ask
Isn't the mortality gap in mental illness mostly suicide?
Suicide matters enormously, but it is not the main driver of the overall gap, and this study deliberately looked past it at physical illness. Cardiovascular, respiratory, endocrine and gastrointestinal disease together account for a large share of the excess deaths. People with severe mental illness are dying of the same conditions as everyone else, only earlier and more often.
What is the difference between absolute and relative excess mortality?
It is the study's central point. Absolute excess counts how many extra deaths occur, which is why cardiovascular disease tops that list: it is common. Relative excess measures how many times higher the rate is than expected, which is why respiratory disease tops that one at 6.49-fold. A condition can be a huge burden without being a huge inequality, and vice versa. The authors argue you need both to set priorities.
Why would respiratory disease show the widest gap?
The study does not test mechanisms, so this is context rather than finding. Smoking rates are markedly higher in people with schizophrenia spectrum disorders, some antipsychotics affect weight and sedation, and access to respiratory care can be poorer. Diagnostic overshadowing, where physical symptoms get attributed to the psychiatric condition, is another recognized contributor.
Do these numbers apply outside Europe?
Cautiously. The five countries studied, Denmark, Finland, France, Poland and Sweden, all have universal health systems and high-quality registers. That makes the data unusually reliable and probably makes the gap conservative: in places with weaker access, disparities are generally larger, not smaller.
What would actually close the gap?
The authors argue for an integrated public health approach combining universal strategies with targeted interventions, addressing both the high-burden causes and those with the greatest relative inequality. In practice that means physical health screening built into psychiatric care rather than left to chance. Anyone with a severe mental illness diagnosis should have blood pressure, blood sugar, lipids and smoking reviewed regularly.