Description of figure 1
Survey of People Living with Psychotic Illness (aged 16–84)
Mental illness includes conditions with low prevalence and severe consequences, including psychotic illnesses and a range of other conditions such as eating disorders and personality disorders (DoHA 2010). Psychotic illnesses may be characterised by symptoms including disordered thinking, hallucinations, delusions and disordered behaviour, and include Schizophrenia, Schizoaffective disorder, and Delusional disorder (Morgan et al. 2011).
Estimates from the 2010 National Psychosis Survey were that 64,000 people in Australia aged 18–64 experienced a psychotic illness and were in contact with public specialised mental health services each year. This equates to 5 cases per 1,000 population or 0.5% of the population (Morgan et al. 2011). The survey found the most frequently recorded of these disorders was Schizophrenia which accounted for almost half of all diagnoses (47.0%). Readers are directed to the full report for further information.
Impact and burden
Mental disorders can vary in severity and be episodic or persistent in nature. A recent review estimated that 2–3% of Australians (about 615,000 people based on the estimated 2017 population) have a severe mental disorder, as judged by diagnosis, intensity and duration of symptoms, and degree of disability caused (DoHA 2013). This group is not confined to those with psychotic disorders and it also includes people with severe and disabling forms of depression and anxiety. Another 4–6% of the population (about 1.2 million people) are estimated to have a moderate disorder and a further 9–12% (about 2.6 million people) a mild disorder.
Mental and substance use disorders, such as Depression, Anxiety and Drug use, are important drivers of disability and morbidity. The Australian Burden of Disease Study 2015 examined the health loss due to disease and injury that is not improved by current treatment, rehabilitative and preventative efforts of the health system and society (AIHW 2019a). For Australia, Mental and substance use disorders were estimated to be responsible for 12% of the total burden of disease in 2015, placing it fourth as a broad disease group after Cancer (18%), Cardiovascular diseases (14%) and Musculoskeletal conditions (13%) (AIHW 2019a). Further information can be found in the Australian Burden of Disease Study: Impact and causes of illness and death in Australia 2015.
In terms of the non-fatal burden of disease, which is a measure of the number of years of ’healthy’ life lost due to living with a disability, Mental and substance use disorders were the second largest contributor (23%) of the non-fatal burden of disease in Australia, behind Musculoskeletal conditions (25%) (AIHW 2019a). In addition, in June 2018, about a third (34%) of people in receipt of the Disability Support Pension had a primary medical condition of ‘psychological/psychiatric’ (AIHW 2019b).
There is an association between diagnosis of mental health disorders and a physical disorder, often referred to as a ‘comorbid’ disorder. From the 2007 NSMHWB of adults, 1 in 8 (12.0%) of people with a 12-month mental disorder also reported a physical condition, with 1 in 20 (5.0%) reporting 2 or more physical conditions.
According to the 2010 National Psychosis Survey, people with a psychotic illness also frequently experience poor physical health outcomes and comorbidities (Morgan et al. 2011). For example, over one-quarter (27%) of survey participants had heart or circulatory conditions and over one-fifth (21%) had diabetes (compared with 16% and 6% respectively in the general population). The prevalence of Diabetes found in the National Survey of People Living with Psychotic Illness is more than 3 times the rate seen in the general population. Other comorbidities included Epilepsy (7% compared with 0.8% in the general population) and Severe headaches/migraines (25% compared with 9% in the general population).
Psychological distress
Another insight into the mental health and wellbeing of Australians is provided by measures of psychological distress. Psychological distress can be described as unpleasant feelings or emotions that affect a person’s level of functioning and interfere with the activities of daily living. This distress can result in having negative views of the environment, others and oneself, and manifest as symptoms of mental illness, including anxiety and depression. The Australian Bureau of Statistics (ABS) measures psychological distress in the National Health Survey (NHS) using the Kessler 10 (K10) psychological distress scale measuring non-specific psychological distress, based on questions about negative emotional states experienced in the past 30 days (ABS 2012).
In 2017–18, 13% or 2.4 million Australians aged 18 and over experienced high or very high levels of psychological distress, a 12% increase from 2014–15 (11.7% or 2.1 million Australians). High or very high levels of psychological distress were more often reported by women than men in 2017–18 (15% and 11% respectively). Of all age groups, young people (aged 18–24) were most likely to experience high or very high levels of psychological distress (15.2%) (ABS 2019b).