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 and tend to die earlier than the general population. More information about mental illness can be found on Mental health services in Australia.

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 between 1.4 and 32 years of potential lost life (Walker et al. 2015). This reduction in life expectancy is well established by numerous studies and reviews and 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, in line with findings from other research, only a small portion (14%) of the gap in life expectancy between the people with mental illness in this study compared to the general population was attributed to suicide, whereas almost 80% was attributed to physical health comorbidities, such as cardiovascular disease, respiratory disease and certain cancers (Lawrence et al. 2013).

The reasons why 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 (RANZCP 2015) 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
  • impacts from polypharmacy, prescribing practices and adverse effects of psychotropic medication, in particular their contribution to metabolic syndrome, obesity, cardiovascular disease and type 2 diabetes
  • 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.

In addition to shorter life expectancy, the consequences of higher rates of physical comorbidity among people with severe mental illness also include 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

Part of the challenge in reporting on the physical health of people experiencing mental illness is a lack of information. A number of initiatives and programs that monitor the physical heath of Australians with mental illness have the potential to provide insight into this important issue, but they are not consistent across jurisdictions and different health settings. While there is no national data set on prevalence of physical illness in mentally ill people, information is available from a number of other data sources. Together these sources provide insight into the chronic conditions and substance use in people with mental illness.

How common is physical illness among people with mental illness?

In the 2007 National Survey of Mental Health and Wellbeing, an estimated 3.2 million Australians reported having a mental health condition, and around 60% of these people also reported having a physical health condition. This represents an estimated 1.9 million people or 11.7% of adults experiencing both a mental health and a physical health condition (ABS 2008).  More recently, the 2017–18 National Health Survey (ABS 2018) results indicated there was a strong overlap between physical health and mental health problems – people who reported having a mental illness were more likely to report having a chronic medical condition, and vice versa. Females with a mental and/or behavioural condition were more likely to have a physical health comorbidity than their male counterparts. The most common chronic conditions reported included back problems, arthritis, and asthma (Table 1). See Chronic conditions and multimorbidity for more information.

Table 1: Chronic conditions of persons with and without mental illness in 2017–18

Selected chronic condition

Persons with mental illness(a) (%)

Persons without mental illness (%)

Arthritis(b)

23.3

13.0

Asthma

18.2

9.5

Back problems(c)

27.7

13.5

Cancer (malignant neoplasms)

2.6

1.6

Chronic obstructive pulmonary disease(d)

5.2

1.8

Diabetes mellitus(e)

6.7

4.4

Heart, stroke and vascular disease(f)

7.1

4.2

Kidney disease

1.9

0.8

Osteoporosis

6.3

3.2

Notes

  1. Includes alcohol and drug problems, mood (affective) disorders, anxiety-related disorders, organic mental disorders and other mental and behavioural conditions.
  2. Includes rheumatoid arthritis, osteoarthritis, other and type unknown.
  3. Includes sciatica, disc disorders, back pain/problems not elsewhere classified and curvature of the spine.
  4. Includes bronchitis and emphysema.
  5. Includes Type 1 and Type 2 diabetes, and type unknown. Estimates also include persons who reported they had diabetes but that it was not current at the time of interview.
  6. Includes angina, heart attack, other ischaemic heart diseases, stroke, other cerebrovascular diseases, oedema, heart failure, and diseases of the arteries, arterioles and capillaries. Estimates include persons who reported they had angina, heart attack, other ischaemic heart diseases, stroke or other cerebrovascular diseases but that these conditions were not current at the time of interview.

Source: ABS 2018. National Health Survey.

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

  • dyslipidaemia (26.2% in patients with severe mental illness compared with 17.7% in patients without)
  • 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 (Morgan et al. 2011) also provides estimates on the physical health of Australians living with psychosis. 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

There is a strong association between the use of alcohol, tobacco and illicit drugs and mental illness. Use of these substances can not only trigger or worsen mental health issues, but is strongly associated with physical health conditions including cancer, cirrhosis, and cardiovascular disease (Crocq 2003).

According to the 2019 National Drug Strategy Household Survey (AIHW 2020), people who had been diagnosed or treated for a mental health condition in the previous 12 months were estimated to be about 20% more likely to report recent or lifetime drinking at risky levels than people who had not been diagnosed or treated for a mental illness (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

30.9

21.3

26.2

20.2

Not diagnosed or treated for a mental health condition

25.3

17.1

15.2

9.9

Notes

  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.

It is important to note that, by themselves, 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).

Use of Illicit drugs 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, at 51%, was 6 times the population figure of 9% (Morgan et al. 2011). See Illicit drug use.

A similar pattern to that for consumers of alcohol and users of illicit drugs is apparent for daily smokers. For example, 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 of people with severe mental illness (47%) are current or past smokers, compared with 30% of the population without severe mental illness (Belcher et al. 2021). Two-thirds (66%) of people with psychosis smoke, smoking on average 21 cigarettes per day (Morgan et al. 2011).

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

While no specific survey or research has been conducted to understand the impacts of the COVID-19 pandemic and related restrictions on 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 for populations 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 among Australians 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 have been 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), various factors meant many in the community have delayed access to healthcare which has the potential to generate acute and long-term health consequences for individuals (see White et al. 2021). Such factors included 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, those experiencing high levels of mental distress were 6 times more likely to choose not to consult a health professional when needed 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 higher burden of comorbid physical illness is a significant health challenge which underscores the need to successfully treat and manage physical illness in people living with mental illness. 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, in particular 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 the significant health disparities experienced by those with mental illness, especially severe mental illness 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. See Mental health services.

Future directions

Increased use of linked data in research has the potential to provide further insights into the relationships between mental illness and physical comorbidities among the Australian population. While separate data collections may only give a limited view on peoples’ overall health, data linkage between collections could facilitate the assessment of the impact of mental illness on a range of physical health conditions across different service settings and could potentially identify areas where people with mental illness are disadvantaged in broader health settings. Data linkage also offers opportunities to identify differences in service usage for people with mental illness, important for this population group which 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: