Schizophrenia and bipolar disorder have been linked to an accelerated accumulation of diseases throughout the body: in young women, the gap reached ninefold.

People with schizophrenia spectrum disorders or bipolar disorder accumulate chronic physical illnesses significantly faster, and over time, these problems affect not just one organ, but multiple body systems. This is the conclusion reached by Australian researchers after analyzing 24 years of medical data from 178,665 people in Queensland. The study was published in The Lancet Psychiatry.

The study included 30,189 people with schizophrenia, other schizophrenia spectrum disorders, or bipolar disorder. They were matched with 148,476 age- and gender-matched participants without these diagnoses—approximately four people from the comparison group for every patient with a severe mental disorder. The median age was only 32-33 years, so the researchers were able to track how somatic illnesses begin to accumulate long before old age.

The gap widened with increasing severity of physical multimorbidity. The likelihood of developing a disease affecting at least one body system was approximately 1.85 times higher, two systems 2.25 times higher, three systems 2.65 times higher, four systems 2.93 times higher, and five or more systems 3.16 times higher, compared to the group without schizophrenia or bipolar disorder. These estimates took into account competing risks of mortality and a number of potentially influencing factors.

The strongest relative effect was found not among older adults, but among women under 25. For chronic diseases affecting five or more body systems, the adjusted subdistribution odds ratio reached 9.24. In other words, the difference between people with severe mental disorders and the matched group was most pronounced at a young age. The authors believe this is a strong argument for initiating physical disease prevention almost simultaneously with a psychiatric diagnosis.

Key findings of the study	Indicator
Total participants	178,665
With schizophrenic or bipolar disorder	30 189
Comparison group	148,476
Data period	2000-2023
Median age of the main group	32 years old
≥1 affected system	sHR 1.85
≥2 systems	sHR 2.25
≥3 systems	sHR 2.65
≥4 systems	sHR 2.93
≥5 systems	sHR 3.16
Women <25 years, ≥5 systems	sHR 9.24

sHR is the adjusted subdistributed hazard ratio in the Fine-Gray model. It should not be literally translated into an individual probability of developing the disease. [1]

What exactly did the researchers study?

The study was a large retrospective cohort study based on Queensland's public health registers. The authors used hospital data from January 1, 2000, to December 31, 2023. The key question was not simply whether diabetes or cardiovascular disease are more common in severe mental disorders, but rather how quickly chronic diseases of different body systems begin to accumulate simultaneously in a single person.

This is where the important concept of systemic physical multimorbidity comes in. Researchers went beyond the traditional definition of "a person has two chronic diseases." They grouped diseases by body systems and sequentially assessed thresholds for reaching one to five affected systems. For example, diabetes and another endocrine disorder could be classified as belonging to a single system, while diabetes plus heart disease plus chronic lung disease signified involvement of three different systems.

The main group included 30,189 patients: 11,940 women and 18,249 men. The median age was 32 years, with an interquartile range of 24 to 42 years. The comparison group included 61,365 women and 87,111 men; the median age was 33 years, with an interquartile range of 24 to 44 years. Matching by age and gender was intended to reduce the influence of the two most obvious factors contributing to physical multimorbidity.

The statistical analysis also took into account the important issue of long-term follow-up: some people may die before they have developed multiple chronic conditions. Therefore, the Fine-Gray competing risks model was used. This is particularly important in studies of severe mental disorders, as premature mortality is inherently higher, and a conventional time-to-event analysis could bias comparisons between groups.

Characteristic	Main group	Comparison group
Participants	30 189	148,476
Women	11,940	61,365
Men	18,249	87 111
Median age	32 years old	33 years old
Interquartile range of age	24-42	24-44
Ratio of groups	1	≈4
Schizophrenic/bipolar disorders	Yes	No

[2]

The more body systems became affected, the more severe the rupture became.

Most revealing is the distinctive "gradient" of the results. For the development of a chronic disease in at least one system, the adjusted subdistribution odds ratio was 1.85, with a 95% confidence interval of 1.81–1.88. This is already a significant difference, but it was only the beginning.

When two systems were affected, the indicator increased to 2.25, for three – to 2.65, for four – to 2.93, and for five or more – to 3.16. This sequence is more important than any single figure: the more severe the person's physical condition became, the more the trajectories of the two groups diverged.

That's why the authors aren't simply talking about an increased incidence of individual diseases. The results point to an accelerated accumulation of systemic multimorbidity. A person may begin with a metabolic disorder, then develop cardiovascular, kidney, or respiratory disease, and over the years, treatment must be built around a complex set of interacting diagnoses and medications.

This has direct clinical significance. The coexistence of multiple illnesses complicates medication selection, increases the likelihood of drug interactions, increases patient burden, and requires coordination across multiple medical specialties. Therefore, the authors believe that physical complications associated with severe mental disorders should be viewed not as a collection of random comorbid diagnoses, but as a distinct systemic problem.

Number of affected systems	Adjusted sHR	95% CI
≥1	1.85	1.81-1.88
≥2	2.25	2.19-2.32
≥3	2.65	2.56-2.74
≥4	2.93	2.81-3.05
≥5	3.16	3.01-3.30

[3]

In absolute numbers, the difference was also large.

Relative rates sometimes create the impression of a huge effect even for a rare event. Therefore, the researchers additionally calculated the absolute difference in cumulative incidence after 20 years. This analysis shows how many additional people out of every 100 reach a certain level of physical multimorbidity.

For a disorder affecting at least one system, after 20 years, the group with schizophrenia or bipolar disorder experienced approximately 9.79 additional cases per 100 people compared to the group without these disorders. For two systems, the difference was 18.43 additional cases per 100 people.

The largest absolute difference was observed at the three-system threshold: 18.57 additional cases per 100 people. For four systems, it was 15.71 cases, and for five or more systems, 11.66 additional cases per 100 people. The decrease in absolute values for the highest thresholds is natural: severe multimorbidity is less common overall, so the potential number of additional cases decreases.

It is the combination of relative and absolute indicators that makes the study's conclusion particularly compelling. In severe multimorbidity, the relative gap reaches threefold, and at more common thresholds, the difference represents approximately 18 additional patients for every 100 people over two decades of observation.

Multimorbidity threshold	Additional cases after 20 years per 100 people	95% CI
≥1 system	+9.79	9.06-10.53
≥2 systems	+18.43	17.58-19.28
≥3 systems	+18.57	17.73-19.42
≥4 systems	+15.71	14.92-16.51
≥5 systems	+11.66	10.95-12.37

[4]

The most alarming result was found in young people.

Multimorbidity is typically associated with old age: the longer a person lives, the more time they have to develop diabetes, hypertension, arthritis, kidney disease, and other chronic conditions. But a new study has revealed a seemingly paradoxical result: the relative gap between groups is greatest among young people.

The increase was particularly pronounced in women under 25. For lesions involving five or more body systems, the adjusted subdistribution odds ratio was 9.24, with a 95% confidence interval of 7.30 to 11.71. This is the highest among the age and sex subgroups presented.

However, the figure 9.24 does not mean that a young woman with bipolar disorder or schizophrenia has, for example, a 90% chance of developing five illnesses. Rather, it refers to the relative rate of reaching a certain multimorbidity threshold compared to comparable young women without these psychiatric diagnoses. The absolute risk of severe multimorbidity at such a young age remains lower than in older people.

But it's precisely this relative difference that has important preventative implications. If somatic risk begins to diverge in the early years of adulthood, waiting until age 40 or 50 to begin intensively monitoring blood sugar, lipids, weight, blood pressure, smoking, and other factors may be too late. Study leader Sean Halstead therefore emphasizes the need to consider physical health from the moment a severe mental disorder is diagnosed.

Researchers assessed diseases of almost the entire body

Physical diseases were categorized into 11 systemic categories. These included cardiovascular, endocrine, gastrointestinal, genitourinary, hematological, chronic infectious, oncological, musculoskeletal, neurological, and respiratory diseases. The final combined category included ophthalmological diseases and diseases of the ear, nose, and throat.

This approach differs fundamentally from studies focusing solely on the classic triad of obesity, diabetes, and cardiovascular disease. Cardiometabolic complications are indeed extremely important in the treatment of schizophrenia and bipolar disorder, but the patients' physical health is not limited to these complications. Respiratory diseases, neurological disorders, musculoskeletal problems, and chronic infections can coexist.

The authors deliberately used a systems approach because two separate diagnoses within a single organ system and diseases affecting multiple systems create different clinical complexities. For example, a person with diabetes and a thyroid disorder has two endocrine diseases, whereas a combination of diabetes, chronic lung disease, and heart failure requires the collaboration of several medical specialties. This illustrates the concept of systemic multimorbidity, although this specific example serves as an explanation of the methodology rather than a standalone study result.

The authors believe that this accumulation of diseases across different systems better reflects the true burden faced by patients and healthcare providers. Previous studies by the same research group also showed that standard multimorbidity indices may miss some conditions important for people with severe mental disorders, such as osteoarthritis or obstructive sleep apnea.

System	Examples of what the category could cover
Cardiovascular	Heart and vascular diseases
Endocrine	Diabetes and other endocrine disorders
Gastrointestinal	Chronic diseases of the digestive system
Urogenital	Diseases of the kidneys and genitourinary system
Hematological	Chronic blood diseases
Infectious	Chronic infections
Oncological	Malignant neoplasms
Musculoskeletal	Diseases of the joints and musculoskeletal system
Neurological	Chronic neurological diseases
Respiratory	Diseases of the lungs and respiratory tract
Eye/ENT	Combined ophthalmology and ENT category

The categories of systems are given according to the methodology of the article; specific diagnoses within them were defined by the authors of the study. [5]

Why can mental disorder be accompanied by such a high somatic risk?

The study was not designed to identify a single cause for the association, and the authors emphasize that the mechanism is likely multifactorial. It may simultaneously include biological predisposition, social conditions, lifestyle factors, medication side effects, and differences in access to quality medical care.

One of the most obvious factors is drug therapy. Some antipsychotic medications can increase appetite and body weight and impair lipid and carbohydrate metabolism. Study co-author Dan Siskind hypothetically describes a young man who, after starting treatment, gains weight, later develops diabetes and kidney disease, and then experiences an increased risk of stroke or heart attack. This is an example of a possible sequence, not proof that the medications explain the entire observed effect.

The second set of factors is related to smoking, alcohol, other substance use, physical inactivity, and diet. The research team and previous studies on multimorbidity show that these factors can particularly significantly increase the incidence of respiratory, infectious, liver, and cardiometabolic diseases. However, they also do not explain all the differences between the groups.

The third component is the social conditions themselves. Severe mental disorders can be accompanied by unemployment, lower incomes, housing instability, and other forms of socioeconomic vulnerability. Social deprivation is independently associated with multimorbidity, so its combination with mental disorders can exacerbate the accumulation of physical illnesses.

Finally, there is the problem of diagnostic overshadowing, when a person's physical complaints are mistakenly attributed primarily to a psychiatric condition or given less attention. The authors and supporting literature also note the reduced availability of certain preventive screenings, including cardiovascular and cancer screenings. Therefore, worse somatic outcomes may reflect not only the biology of the disease but also inequalities within the healthcare system.

Possible factor	How does it potentially affect
Genetic and biological factors	General predisposition to mental and physical illnesses
Antipsychotic drugs	Body weight, glucose, lipids and other side effects
Smoking	Cardiovascular and respiratory diseases
Alcohol and other substances	Liver, infections, cardiovascular risk
Low physical activity	Cardiometabolic risk
Social deprivation	Increases the risk of multimorbidity
Insufficient screening	Later detection of diseases
Diagnostic eclipse	Physical symptoms may be underestimated

None of these factors was identified by the new study as the sole cause of the observed association.[6]

Why physical illness matters so much for life expectancy

People with schizophrenia and bipolar disorder have, on average, a significantly shorter life expectancy than the general population. In a public commentary on the study, the authors note that this gap can reach 10-20 years, with a significant portion of this being due not only to suicide but also to chronic somatic illnesses.

This is an important clarification, as mortality in severe mental disorders is often associated primarily with the risk of suicide. Suicide is indeed a critical issue, but cardiovascular, metabolic, respiratory, and other physical illnesses create a significant additional burden. This new study helps to understand one possible mechanism for this gap: somatic illnesses are not only more common, they begin to accumulate earlier.

Early onset has long-term consequences. If diabetes develops not at age 60, but rather in one's 30s or 40s, the body is exposed to elevated glucose levels for a much longer period. The same applies to hypertension, chronic lung disease, or kidney disease. This is a biologically plausible explanation for why earlier multimorbidity may contribute to premature disability and mortality, although the current study did not directly calculate the proportion of mortality caused by each condition.

Therefore, the authors propose changing the very model of patient management. Psychiatric stabilization remains necessary, but successful treatment cannot be considered when psychosis or affective symptoms are controlled while rapidly increasing body weight, glucose levels, blood pressure, shortness of breath, or other physical problems are ignored.

Prevention is recommended to begin almost immediately after diagnosis.

The main practical conclusion of this study is not to wait for the emergence of multimorbidity. If the greatest relative gap is observed in young adults, preventive strategies should begin in the early years of illness or even at the first episode of psychosis, rather than after decades of treatment.

This means regular monitoring of baseline somatic parameters: body weight and waist circumference, blood pressure, glucose and glycated hemoglobin, lipids, smoking, and other risk factors. The specific frequency of screening depends on the diagnosis, medication, age, and current clinical guidelines; the new article did not test a specific screening schedule.

The authors specifically point to the possibility of more active prevention of metabolic side effects of therapy. Related studies in this group discuss weight management strategies and, in appropriate clinical situations, the use of drug interventions to prevent significant metabolic deterioration. However, the current study is epidemiological and did not compare the efficacy of metformin, glucagon-like peptide-1 receptor agonists, or other drugs.

Equally important is the organization of care. The authors advocate a model in which psychiatrists, primary care specialists, and somatic physicians do not view patients as a set of independent diagnoses. If multimorbidity is systemic, medical care should also be integrated, with shared responsibility for the prevention, early detection, and treatment of physical illnesses.

It can be controlled at an early stage	For what
Body weight and waist circumference	Early detection of metabolic changes
Blood pressure	Prevention of cardiovascular risk
Glucose/glycated hemoglobin	Detection of prediabetes and diabetes
Lipid profile	Atherosclerotic risk assessment
Smoking	One of the most important modifiable factors
Alcohol and substances	Reducing somatic risk
Physical symptoms	Preventing diagnostic eclipse
Side effects of psychotropic therapy	Possibility of early correction

This is a practical interpretation of the results, not the intervention protocol tested in this study.[7]

An important limitation: the study does not prove that schizophrenia itself “causes” diseases throughout the body.

The first and foremost limitation is that the study was observational. Patients were not randomly assigned to the presence or absence of a mental disorder, so the observed association does not prove direct causation. Numerous genetic, social, behavioral, and treatment factors are associated with schizophrenia and bipolar disorder, and it is impossible to completely separate them statistically.

The second limitation concerns the data source. The comparison group was drawn from hospital patients, not from a perfectly representative random sample of the entire Queensland population. The authors explicitly note that future studies should use broader, combined primary and hospital care data and a comparison with a population more representative of the general population.

A third issue is the possibility of differences in the frequency of contact with the healthcare system. A person with a severe mental disorder may be hospitalized more frequently and, therefore, have a greater opportunity to detect a physical illness. The researchers conducted sensitive analyses, including restricting the sample to people with multiple hospitalizations and accounting for hospitalization frequency; the difference narrowed but remained statistically significant. This reduces, but does not completely eliminate, the risk of observational bias.

A fourth limitation is the lack of data on the participants' ethnicity. This is particularly important for the Australian healthcare system, as health status and access to care can vary significantly across populations, including Indigenous peoples. Therefore, the study cannot reliably determine whether the observed patterns are consistent across all ethnic groups.

Finally, the study measures the presence of diagnoses in medical registries rather than continuously measuring a patient's biological status. Milder illnesses that are treated only by a family doctor and never result in hospitalization may be underreported. Therefore, integrating hospital data with primary care is an important next step.

What the study showed—and what it didn't show

Correct conclusion	Incorrect interpretation
In schizophrenic and bipolar disorders, diseases of different systems accumulate more quickly.	"Mental disorder directly causes all these diseases."
For ≥5 systems, the sHR was 3.16	"Each patient has a 316% risk of developing the disease."
In women <25 years old, the sHR reached 9.24	"Nine out of 10 young women will develop five diseases."
The absolute gap for ≥3 systems was +18.57 per 100 over 20 years	All patients will inevitably develop multimorbidity.
The association remained after statistical adjustments.	All confounding factors are completely excluded
Physical prevention is needed early	The study proved a specific best prevention regimen
The results cover 24 years of Queensland data.	The numbers are automatically identical for any country.
The work concerns the schizophrenic and bipolar spectrums.	The results apply to all mental disorders.

[8]

Why the results are especially important now

The new study expands on a previous systematic review by the same research group. In 2024, the authors showed that physical multimorbidity is already present in approximately 25% of people with severe mental disorders, and the odds of multimorbidity are approximately 2.4 times higher than in people without such disorders. The difference was particularly pronounced in relatively young samples.

But prevalence only answers the question "how many people already have the disease." The new study goes further and evaluates incidence—the emergence and accumulation of new diseases over time. This is why its conclusion about early divergence of trajectories has more direct relevance to prevention.

The results also show why a single annual formal check-up may not be sufficient. If the detected increased risk is due to a combination of medication, social, behavioral, and medical factors, effective intervention is necessary once the abnormality is identified—treating hypertension or diabetes, helping with smoking cessation, managing metabolic side effects, and ensuring access to specialized care. The study itself did not test the effectiveness of such a comprehensive program.

More broadly, the work supports the idea that the medical division into "mental" and "physical" health is too artificial for this group of patients. When a young person's mental disorder is accompanied by years of accelerated disease progression across various organs, the goal of treatment becomes not only the control of psychiatric symptoms but also the maintenance of overall health for decades to come.

Results

An Australian study of nearly 180,000 people shows that schizophrenia, other schizophrenia spectrum disorders, and bipolar disorders are associated not only with a higher prevalence of individual physical illnesses, but also with a much faster accumulation of chronic diseases across multiple body systems.

The gap widened with the severity of multimorbidity: the adjusted rate was 1.85 for one affected system and 3.16 for five or more systems. After 20 years, patients with severe mental disorders experienced approximately 18 additional cases per 100 people at the threshold of two or three affected systems.

The age-related pattern is particularly important. The greatest relative difference was observed not among the elderly, but among young people; in women under 25, the sHR for reaching five or more affected systems was 9.24. This does not imply an extremely high absolute risk for each young patient, but it does indicate that the divergence in physical health begins unusually early.

Therefore, the study's main conclusion is that the physical health of a person with schizophrenia or bipolar disorder should not be seriously monitored only after diabetes, heart disease, or kidney disease has developed. The authors believe that prevention should be part of psychiatric care from the very onset of the disease, as by the time several chronic diagnoses have developed, a significant number of opportunities for prevention may have already been missed.

News source

Halstead S., Warren N., Kisely S., Arnautovska U., Trott M., Correll CU, Ebdrup BH, Heffernan E., Høgnason Mohr G., McCutcheon RA, Morley KI, O'Donoghue B., Pillinger T., Sara G., Taipale H., Siskind D. Incidence of systemic physical multimorbidity among people with schizophrenia-spectrum or bipolar-spectrum disorders compared with age-matched and sex-matched individuals in Queensland, Australia: a statewide, hospital cohort study. The Lancet Psychiatry. 2026;13(9):771-782.

DOI: 10.1016/S2215-0366(26)00196-3.

The study is an open scientific publication. The authors indicate that there was no separate funding source for the study.

The publication discloses potential conflicts of interest for individual co-authors; for example, Christoph U. Correll reported consulting, expert, or honorarium relationships with several pharmaceutical companies. These declarations are presented in the original article and are important for transparency, even though the primary work is an analysis of national medical registries, not a drug trial.