People living with mental illness, and in particular severe (and often long-term) mental illness, such as a psychotic disorder like schizophrenia, are more likely to develop comorbid physical illness, more likely to be hospitalised for potentially preventable reasons (Sara et al. 2021) and tend to die earlier than the general population. More information about mental illness can be found at the AIHW Mental health site.

A meta-analysis of studies worldwide has estimated that people with mental illnesses have a mortality rate 2.2 times that of people without, and an average of 10 years of potential lost life (Walker et al. 2015). There is also evidence that this gap is increasing (Firth et al. 2019). Research from Western Australia found that the gap in life expectancy for people with mental illness registered with West Australian mental health services – compared with the general population – increased between 1985 and 2005, from 13.5 to 15.9 years for males and 10.4 to 12.0 years for females. Notably, like other research, only a small portion (14%) of the gap in life expectancy for people with mental illness in this study compared to the general population was attributed to suicide. Most (80%) of the gap was attributed to physical health comorbidities, such as cardiovascular disease, respiratory disease and certain cancers (Lawrence et al. 2013).

The reasons people with mental illness are more likely to experience physical comorbidity are multifactorial and complex. According to the Royal Australian and New Zealand College of Psychiatrists these include:

  • Greater exposure to the known risk factors for physical disease such as socio-economic status, smoking, poor nutrition, reduced physical activity and higher sedentary behaviour.
  • Reduced access to and quality of healthcare due to financial barriers and stigma and discrimination among healthcare providers.
  • Systemic issues in health-care delivery, especially the separation of mental and physical health services, and a lack of clarity about who is responsible for monitoring the physical health of people with serious mental illness
  • Adverse effects of psychotropic medication, in particular their contribution to metabolic syndrome, obesity, cardiovascular disease and type 2 diabetes.
  • Impacts from polypharmacy (the prescription of multiple medications) and prescribing practices
  • Lack of capability among both generalist and specialist healthcare staff to deal with complex comorbidities – mental health staff may lack skills, training and confidence to treat physical conditions and vice versa for physical health teams (RANZCP 2015).

In addition to shorter life expectancy, higher rates of physical comorbidity among people with severe mental illness can lead to higher levels of ongoing disability due to both physical and mental illness, reduced participation in the workforce and a greater likelihood of poverty and welfare dependency (RANZCP 2015).

Measuring the physical health of people with mental illness

One challenge in reporting on the physical health of people experiencing mental illness is a lack of information. Initiatives and programs that monitor the physical heath of Australians with mental illness may provide insight into this important issue, but they are not consistent across jurisdictions and different health settings. While there is no specific or detailed national data set on the prevalence of physical illness among people living with mental illness, information is available from of other data sources, such as the National Study of Mental Health and Wellbeing (NSMHW).

How common is physical illness among people with mental illness?

According to the 2020–21 NSMHW, an estimated 4.2 million Australians aged 16–85 years, or 21% of this population, had experienced a mental illness at some time in their life and had symptoms of that illness in the 12 months prior to the survey. Of these people, 42% also had a long-term physical health condition, compared with 38% of those who did not have a mental illness in the 12 months prior. This represents an estimated 1.8 million people or 9% of adults experiencing both a mental illness and a long-term physical health condition (ABS 2022a).

More recently, 2021 Australian Census results – which include people of all ages – also showed a strong overlap between physical health and mental health problems; people who reported having a mental illness were more likely to report having a long-term health condition (ABS 2022b). Among the most common long-term conditions reported by those with a mental illness were arthritis, asthma and diabetes (Table 1). Furthermore, given that the Census relies on people self-reporting conditions, this is likely to be an underestimate as many people did not respond to this item or may not be aware that they have a long-term health condition. Refer to Chronic conditions and multimorbidity for more information.

Table 1: Long-term health conditions reported by persons with and without mental illness in 2021
Selected long-term health condition Persons with mental illness(a) (%) Persons without mental illness(a) (%)







Cancer (including remission)



Diabetes (excluding gestational diabetes)



Heart disease (including heart attack or angina)



Kidney disease



Lung condition (including Chronic obstructive pulmonary disease (COPD) or emphysema)






Any other long-term health condition(s)(b)



a. Includes depression or anxiety
b. Excludes dementia, Alzheimer’s disease and mental illness
Source: ABS 2022b.

A recent study of Australian general practice records comparing the prevalence of selected physical health conditions and biomedical risk factors has similarly shown a strong association between mental and physical illness (Belcher et al. 2021). The prevalence of all surveyed biomedical risk factors was higher among patients with severe mental illness than patients without. These included:

  • dyslipidaemia (high cholesterol) (26.2% compared with17.7%)
  • hypertension (27.2% compared with 22.1%)
  • obesity (29.0% compared with 18.6%).

The prevalence of all surveyed physical conditions was also higher among patients with severe mental illness than patients without. These included:

  • back pain (35.1% among those with severe mental illness compared with 19.4% in patients without)
  • gastro-oesophageal reflux disease (29.1% compared with 14.9%)
  • arthritis (27.4% compared with 18.7%)
  • cancer (19.4% compared with 14.9%).

Almost three-quarters (71.1%) of patients with severe mental illness had at least one of the selected physical health conditions, compared with about half (53.6%) of people without.

The second national survey of People Living with Psychotic Illness also provides estimates on the physical health of Australians living with psychosis (Morgan et al. 2011). Chronic back, neck or other pain were the most common chronic physical conditions (32% compared with 28% for the general population) identified among people with psychosis in 2010. Other common conditions included asthma (30% compared with 20% for the general population) and heart or circulatory conditions (27% compared with 16%).

In 2010, one-quarter (24%) of people with psychosis were at high risk of cardiovascular disease. Almost half (45%) of people with psychotic illness were obese and almost two-fifths (38%) reported gaining weight as a medication side effect. Physical activity levels were far lower in people with psychosis, with 96% classified as either sedentary or undertaking low levels of exercise in the previous week compared with 72% for the general population (Morgan et al. 2011).

Substance use and mental illness

Use of alcohol, tobacco and illicit drugs can trigger or worsen mental health issues and are strongly associated with physical health conditions including cancer, cirrhosis, and cardiovascular disease (AIHW 2022).

According to the 2019 National Drug Strategy Household Survey (AIHW 2020), people who were diagnosed or treated for a mental health condition in the previous 12 months were about 20% more likely to report recent or lifetime drinking at risky levels than people who had not (Table 2). According to Australian general practice records (Belcher et al. 2021), the prevalence of moderate to heavy drinking among patients with severe/long-term mental illness was 4.7%, more than double that for the population without (2.2%).

Table 2. Percentage of people aged 18 years and over who use alcohol, tobacco and illicit drugs by mental health status in 2019

Mental illness(a)

Alcohol use(b)
Single occasion risk (at least monthly) (%)

Alcohol use(b)
Lifetime risk (%)

Any illicit drug use (%)

Daily smoking (%)

Diagnosed or treated for a mental health condition





Not diagnosed or treated for a mental health condition






  1. Includes depression, anxiety disorder, schizophrenia, bipolar disorder, an eating disorder and other form of psychosis.
  2. Alcohol data are reported against the 2009 Australian alcohol guidelines.

Source: AIHW 2020.

Critically, these findings do not establish a causal link between mental illness and drug use – the mental illness may have preceded the drug use or vice versa (AIHW 2021a).

Illicit drug use is also common among people with mental illness. In 2019, compared with people with no mental illness, people with a mental health condition were 1.7 times as likely to have used any illicit drug in the previous 12 months and about twice as likely to have used meth/amphetamine and pharmaceuticals for non-medical purposes (AIHW 2020). The lifetime rate of any substance use or dependence in people with psychosis, was 51%, 6 times the population figure of 9% (Morgan et al. 2011). Refer to Illicit drug use.

People who reported a mental health condition were twice as likely to smoke daily as those who had not been diagnosed with, or treated for, a mental health condition (20% compared with 9.9%) (Table 2) (AIHW 2020). Likewise, according to Australian general practice records, almost half (47%) of people with severe mental illness are current or past smokers, compared with one third (30%) of the population without severe mental illness (Belcher et al. 2021). Two-thirds (66%) of people with psychosis smoke, with an average of 21 cigarettes per day (Morgan et al. 2011).

COVID-19 and the physical health of people living with mental illness

A number of data sources have indicated impacts on both the mental and physical health of Australians during the pandemic. As in other parts of the world, the pandemic and related restrictions had significant impacts on the mental health of Australians, with multiple sources of data indicating increased and more widespread psychological distress compared with pre-pandemic levels (ABS 2021; Biddle and Gray 2021; Butterworth 2020), and increased use of mental health services and mental health prescriptions (AIHW 2021a). Those aged 18–35 years, women, people with a disability, renters and people who report having a mental health condition were more likely to report high or very high levels of psychological distress (ABS 2021).

Despite modifications and additions to health service delivery models during the pandemic (for example, telehealth consultations), many people have delayed access to healthcare which may lead to acute and long-term health consequences for individuals (see White et al. 2021). Issues include restrictions on movement during lockdowns, fear of contracting COVID-19, fear of overburdening the health system, financial stress and disruptions to elective surgery and other health services. Notably, people experiencing high levels of mental distress were 6 times more likely to choose not to consult a health professional when than those not experiencing mental distress (Zhang et al. 2020).

For both waves of COVID-19 during 2020, despite restrictions on movement and social participation, the AusPlay physical activity survey (Sports Australia 2021) indicated a national increase in adult participation in sport or physical activity at frequencies of higher than 5 and 7 times a week – an increase which appears to be driven by women. No clear patterns have emerged on the impact of the pandemic on drug and alcohol consumption in Australia, with the majority of people reporting unchanged levels of consumption. More information can be found on drug and alcohol use during the pandemic at Impacts of COVID-19 on alcohol and other drug use.

Treatment and management

The physical health of people living with mental illness was named as a key priority area in the Fifth National Mental Health and Suicide Prevention Plan (Department of Health 2017) and improving physical health and reducing early mortality among people living with mental illness remains an ongoing priority.

Factors contributing to the poorer health of people experiencing mental illness, particularly severe mental illness are multiple and complex. According to the Royal Australian and New Zealand College of Psychiatrists report Keeping Mind and Body Together (2015), addressing health disparities will involve:

  • population health measures
  • lifestyle interventions, especially those with a focus on the importance physical exercise
  • interdisciplinary, collaborative and integrated care that bridges the gap between primary and secondary care and reduces barriers between physical and mental health services
  • management of psychotropic medications and specifically the implementation of metabolic monitoring for those with serious mental illness
  • building the capacity of consumers to self-manage
  • tacking stigma and discrimination, including among healthcare professionals.

The National Mental Health Commission (2022) has called on organisations around Australia to pledge support for the principles in the Equally Well Consensus Statement which provide guidance on bridging the gap in life expectancy between people living with mental illness and the general population. All Australian state and territory and federal governments have expressed support for the statement.

Future directions

Use of linked data may provide further insights into the relationships between mental illness and physical comorbidities among the Australian population. While separate data collections provide a limited view on peoples’ overall health, data linkage between collections allows for analysis of the impact of mental illness on physical health conditions from across different service settings and types of service usage. This data could assist in identifying areas of disadvantage in broader health settings and barriers to service usage for people with mental illness, which is critical as this this population group accesses health services at a lower rate than the general population.

Where do I go for more information?

For more information on the physical health of people with mental illness, see: