Figure 2: Types of serious illness by age and sex, 2009 to 2021

Figure 2: Types of serious illness by age and sex, 2009 to 2021

Mental illness includes conditions with relatively low prevalence and potentially severe consequences, such as psychotic illnesses (Department of Health and Ageing 2010). Psychotic illnesses may be characterised by symptoms including disordered thinking, hallucinations, delusions and disordered behaviour, although individual experiences vary greatly. Diagnoses include Schizophrenia, Schizoaffective disorder and Delusional disorder.

The 2010 National Psychosis Survey estimated that 64,000 Australians 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. The survey found the most frequently recorded of these disorders was Schizophrenia which accounted for almost half of all diagnoses (47%) (Morgan et al. 2011).

Change over time

Prior to 2020–2022, the NSMHW was last undertaken in 2007. Between the two surveys, prevalence of mental illness among the Australian population remained broadly similar, with 45% of Australians aged 16–85 years having a lifetime mental disorder in 2007, compared with 43% in 2020–2022. In 2007, an estimated 20% of Australians had a 12-month mental disorder, compared with 22% in 2020–2022.

Between the two surveys, the prevalence of a 12-month mental disorder remained the same among males (18% for both), but there was an increase among females (from 22% in 2007 to 25% in 2020–2022).

While the prevalence of a 12-month mental disorder remained broadly similar between the two surveys for people aged 25–85, there was a , 26% of those aged 16–24 had a 12-month mental disorder; in 2020–2022, this figure was 39%. This change is almost entirely driven by an increased prevalence of mental illness among females in this age group: 30% of females aged 16–24 years in 2007 had a 12-month disorder, compared with 46% in 2020–2022 (the prevalence for males of this age group increased from 23% to 32%). Continue reading