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Mental illness in Australia and NSW

How many people in NSW experience mental illness, and what are their demographic characteristics? This section provides information on available statistics in order to describe the scope and nature of mental illness experienced in Australia and NSW.²²

Statistics for this section were drawn from the following sources:

• The Mental Health of Australians, 1999²³

In 1997, the Commonwealth Department of Health and Aged Care undertook a comprehensive survey of the mental health of Australians. The product of their effort was the National Survey of Mental Health and Wellbeing (NSMHW), which comprised both an adult component and a section outlining the same issues for children and young people (see below for a description of the child component). The report outlines statistics obtained on the national incidence of high prevalence disorders (i.e. affective disorders, anxiety disorders, and substance use disorders) for all Australian adults. Importantly, the study used a structured diagnostic interview that mapped the symptoms elicited during the interview onto DSM-IV and ICD-10 diagnostic criteria. The validity of this study was therefore greatly enhanced beyond self-reported measures of mental illness.

• Child and Adolescent Component of the NSMHW, 2000²⁴

This report outlines the findings of the NSMHW for children and adolescents aged 4–17. The prevalence among young people of three mental disorders (depressive disorder, conduct disorder and attention-deficit/hyperactivity disorder) is reported. Also detailed is the prevalence of mental health problems, quality of life and health-risk behaviour among adolescents, as reported by adolescents themselves.

• People living with psychotic illness: an Australian study, 1997–98²⁵

This report was conducted in conjunction with the NSMHW, and aimed at estimating the prevalence of low prevalence disorders (e.g. psychotic disorders) in Australia.

• Mental Health and Wellbeing Profile of Adults: NSW, 1997²⁶

Based on data extrapolated from the NSMHW, the ABS has released profiles of the mental health of adults in each of the states, including NSW.²⁷ Only the high prevalence disorders (affective, anxiety and substance use disorders) are reported in this profile.

• Australia’s Health, 2004²⁸

As part of the Australian Institute of Health and Welfare’s (AIHW) reporting of national statistics on the health of Australians, this report incorporates both NSMHW statistics and the ABS figures obtained from the 2001 NHS.²⁹

Due to under-reporting and sample limitations, most estimates of mental illness prevalence outlined in the above studies have been appropriately described as underestimates of actual prevalence. Furthermore, these sources have collected no or limited information about certain groups, such as Indigenous Australians and people from culturally and linguistically diverse backgrounds, as well as people living in institutions such as hospitals, colleges, sheltered accommodation and prisons, members of the armed services, and homeless persons.³⁰

These studies provide the bulk of the information available on people with mental illness in Australia and NSW. However, due to the limitations described above, the statistical data are somewhat deficient, a situation which has been noted in several publications to date.³¹

High prevalence disorders: adults

Figures taken from the adult component of the NSMHW reveal that an estimated 17.7 to 18% of adults in Australia had experienced an anxiety, affective or substance use disorder, or a combination of these, in the 12 months preceding the 1997 survey. These rates mean that, overall, approximately 2 383 000 Australian adults had a high prevalence mental disorder.³² The NSW estimate at 17.4% (approximately 800 000 people) was not markedly different from the national average.³³

Breaking down these figures further into the separate disorders, the prevalence of affective disorders was shown to be 5.8% of all adults within the Australian adult population and 5.4% of adults in NSW. Anxiety disorders were found to affect 9.7% of adults within Australia and 9.9% of adults in NSW. With respect to substance use disorders, the prevalence was shown to be 7.7% of all adults in the Australian population, a figure which was matched exactly in NSW adults.

Psychotic mental illnesses: adults

Prevalence figures for psychotic illness were reported in a study examining the low prevalence disorders component of the NSMHW.³⁴ This component studied people living with psychotic disorders in catchment areas in the Australian Capital Territory, Queensland, Victoria and Western Australia. Prevalence estimates for the national population were extrapolated from these samples.

Nationally, the prevalence of psychotic disorders in the adult population is estimated to be in the range of 4 to 7 per 1000 people.³⁵ The range of prevalence is dependent on the area under study, with rural and remote areas being under-reported in the study.³⁶ Schizophrenia and schizoaffective disorders (as per the DSM-IV)³⁷ account for over 60% of reported psychotic disorders.³⁸

Co-morbid substance use disorder (dual diagnosis)³⁹ complicates the course of psychotic illness in a substantial proportion of cases: 30% report a history of alcohol abuse, 25.1% a history of cannabis abuse and 13.2% a history of other substance abuse.⁴⁰ According to Australia’s Health:

Although less common than disorders such as anxiety and depression, psychotic disorders such as schizophrenia represent a very serious group of illnesses that affect brain functioning, perceptions, emotions and communication.⁴¹

Overall prevalence estimate: adults

In relation to their figure of approximately one in five Australians experiencing a mental illness, the authors of The Mental Health of Australians state:

The overall figure for any mental disorder is likely to be more than one in five after neurasthenia, psychosis, personality disorder and cognitive impairment are included, and after one adds in the fifth of the population who could not be contacted or who refused to be interviewed in the Survey.⁴²

The 2001 NHS provides more recent estimates of the prevalence of mental health problems in Australia. Unlike the 1997 NSMHW, which used a structured diagnostic interview, the NHS estimates are based on self-reports (a method more likely to lead to underestimates). Almost 9.6% of respondents reported a long-term mental or behavioural problem. The NHS also measured psychological distress using the Kessler Psychological Distress Scale.⁴³ In total, about 18% of adult respondents reported a mental or behavioural problem, and/or had a very high or high level of psychological distress, with 12% reporting both a mental or behavioural problem and a very high level of psychological distress. In summary, both of these key sources indicate that a significant number of people in Australia, approximately one in five people, experience mental illness.

Prevalence of mental illness: children and adolescents

The child and adolescent component of the NSMHW found that 14% of children and adolescents have mental health problems, and this high prevalence extended across all age and gender groups. There was a higher prevalence of child mental health problems among those living in low-income, step, blended and sole parent families.⁴⁴

Demographics and high prevalence disorders

Gender

According to the NSMHW, mental illness in general affects 17.4% of Australian males and 18% of Australian females within the adult population.⁴⁵ The NSW estimate is 16.9% for males and 17.9% for females.

As can be seen in Table 1, nationally, men were much more likely to have a substance use disorder than women (11.1% versus 4.5%), while women were much more likely than men to have an anxiety disorder (12.1% versus 7.1%) or an affective disorder (7.4% versus 4.2%). The survey found approximately the same magnitude of difference for NSW in the measurement of prevalence of substance use disorders (10.4% versus 5%), while for anxiety and affective disorders the prevalence for women was again greater than for men, with anxiety at 12.8% versus 7%, and affective disorders at 6.8% versus 4%.

Table 1: Prevalence of disorders in NSW and Australia

	Females		Males
	NSW%	Australia%	NSW%	Australia%
Anxiety disorders	7	7.1	12.8	12.1
Affective disorders	4	4.2	6.8	7.4
Substance use disorders	10.4	11.1	5	4.5
Total mental disorders	16.9	17.4	17.9	18

Geographical area

Again, based on the NSMHW, the ABS reports that nationally, the prevalence of mental illness generally is equivalent between “capital city” (17.5%) and “rest of State” (17.3%) areas.⁴⁶ However, different patterns emerge when these figures are broken down. From a sample of adults, both male and female, it was observed that substance use disorders were more prevalent in the city than in the rest of the state (8.2% versus 6.8%), while anxiety disorders were more prevalent in the rest of the state than in the capital city (11.1% versus 9.2%).

The pattern of mental illness between the sexes showed more interesting discrepancies between capital city and rest of state samples: for males, the rates of anxiety disorders were equivalent (7.0% capital city versus 7.1% rest of state), while the rates of anxiety disorders for females varied distinctly (11.4% capital city versus 15.1% rest of state). Likewise, the rates of substance use disorders for males varied considerably between capital cities and the rest of the state (11.6% capital city versus 8.3% rest of state), while the rates for females were not very different (4.9% capital city versus 5.2% rest of state).

Table 2: Mental illness in NSW according to geographic area and gender

Geographic Area	Males%	Females%
Capital city	17.6	17.5
Rest of state	15.8	18.8

The NSW picture shows a slightly different pattern: for males, compared to an approximately equivalent national rate in capital city versus rest of state (i.e. 17.1% versus 17.5%), the NSW statistics show that rates of mental illness are actually lower for the rest of the state than for the capital city (17.6% capital city versus 15.8% for rest of state). The rates for women in NSW more closely reflect the national statistics (17.5% capital city versus 18.8% rest of state).

Age and gender

Figure 1 shows the prevalence statistics among women for different types of mental illness in Australia. As can be seen, the highest rate of anxiety disorders was observed in females aged 45–54 years (16%). The NSW statistics tell a different story, where the highest prevalence of anxiety disorders is in women aged 18–24 years (17.5%). Also, the prevalence in women aged 45–54 years was the same as for women aged 35–44 years (17.1%).

Figure 1: Females, prevalence of types of mental disorders by age, in Australia.⁴⁷

In the Australian adult population, the prevalence of affective (mood) disorders was highest for women aged 18–24 years at 11%, more than three times the rate for men of this age (see Figure 2). This is quite a similar pattern to the NSW profile, where the same age group had the highest prevalence (females, aged 18–24), but the rate was slightly lower (9.2% compared to 11.1% national average). For women, the prevalence of affective disorders generally declined with age, while for men rates increased in the middle years before declining after age 55.

Figure 2: Males, prevalence of types of mental disorders, by age, in Australia.⁴⁸

The NSMHW obtained information on the use of alcohol and four groups of drugs that included both illegal and prescription drugs. Young men were particularly prone to substance use disorders, with about one in five of those aged 18–24 being affected. For both men and women, the prevalence of substance use disorders declined with age to 1.1% of those aged 65 years and over. Alcohol use disorders were about three times as common as drug use disorders. In terms of prevalence, the NSW statistics on substance use disorders are slightly below the national average. While the same age and gender group has the highest prevalence (males aged 18–24), the NSW rate was markedly below the national rate, at 16.0% as opposed to 21.5%.⁴⁹

Living arrangements and marital status

After adjusting for age, the prevalence of mental disorder across Australia was highest for both men and women living alone.⁵⁰ This was also the case for anxiety, affective and substance use disorders individually. Overall, the prevalence of mental illness decreased as the number of people living in a household increased. Rates of mental disorder were also highest among those who were separated or divorced (24% of men and 27% of women). People who had never married also had higher rates of mental disorder than those who were married. In terms of specific disorders, those who were separated or divorced had higher rates of anxiety and affective disorders (18% and 12%, respectively). Of those never married, 14% had substance use disorders.

In terms of the rates of mental illness in people living alone as opposed to those living with other people, patterns in NSW differed according to gender.⁵¹ While the highest rate of mental illness in men was found in those living alone (18.9%), the number of people living in the household impacted differently on women. The highest prevalence of mental illness in women was in those living in households of four or more people (20.4%), compared to 15.6% and 14.9% for females living alone or with one other person respectively.

As to marital status, in NSW, as in the rest of Australia, the highest rates of mental illness are experienced by people who are separated or divorced (27.7% of men and 29.9% of women). This is followed by the rates in people who have never been married (as per the national statistics). Similar patterns exist for the type of mental illness by marital status in NSW as for the rest of Australia.

Employment

After adjusting for age, rates of mental disorder across Australia were highest for men and women who were unemployed or not in the labour force.52 People employed part-time were more likely to have mental disorders than their full-time counterparts. Unemployed people had relatively high rates of substance use disorders (19% of men and 11% of women). Unemployed women also had a high rate of anxiety disorders (20%).

In NSW, similar patterns emerge in regard to unemployed people, who have the highest rates of mental illness in the state, with 43.9% experiencing some form of mental disorder. However, rates for people not in the labour force (15.5%) are not as high as for those in part-time employment (19.4%).⁵³ People in part-time employment experience rates of mental illness of 16% and 20.7% for males and females, respectively, as compared to rates of 12.9% and 17% for people not in the labour force. Interestingly, while the national pattern applied to women in NSW—females in part-time employment being more likely to have mental disorders than their full-time counterparts—the figures were different for NSW men. The survey found that NSW males in full- and part-time employment experienced equivalent rates of mental illness (16.2% and 16.0%, respectively).

The rates of substance use disorders for unemployed people in NSW were substantially higher than the national average, with 34.6% of unemployed men and 18.3% of unemployed women in NSW experiencing substance use disorders, compared to 19% and 11% of the national sample. Rates of anxiety disorders in unemployed people were also higher in NSW than nationally.

Education

These statistics for labour force status dovetail with those relating to a person’s highest educational qualification. According to the literature,54 mental illness can often be most debilitating in the years when a young person is finishing school or beginning post-school study. Mental illness can therefore have a negative impact on a person’s ability to attain the highest educational qualification possible. This argument is supported in the ABS figures,55 which show that in NSW the rate of mental illness (15.6%) is lower in people who have completed some post-school qualification than in those who have either failed to complete school, or completed only secondary school (21.1% and 18.5%, respectively). A similar pattern is found in data for the whole of Australia.⁵⁶

Non-English speaking background

According to the ABS figures, people born in Australia and people born in other countries whose main language is English have equivalent rates of mental illness (18.4% of adults), while people born in non-English speaking countries tend to have lower rates of mental illness (12.5%).⁵⁷ While these figures suggest that there may be lower incidence of mental illness in people of non-English speaking background, research conducted using qualitative methods has raised some other concerns around this issue.58 It is also possible that the survey instruments used to assess prevalence may not be trans-culturally sensitive.

Indigenous Australians

As noted above, the key Australian studies collected only very limited statistics on the mental health of Indigenous Australians. Both Andrews et al.⁵⁹ and Jablensky et al.⁶⁰ indicated that separate studies, investigating the mental health of Indigenous Australians, and using culturally appropriate survey methods and interview schedules, are required and should be conducted.

On the issue of obtaining data on Aboriginal mental health, the South Australian government’s final submission to the Bringing Them Home inquiry noted:

The area of Aboriginal mental health is poorly understood; few experts would claim to fully understand the normal Aboriginal psyche or to confidently diagnose deviations … Many of the so called mental health issues in the Aboriginal Community result from striving to fulfill the expectations of two different cultures—about finding a sense of place.⁶¹

Despite the lack of data, the Human Rights and Equal Opportunity Commission (HREOC) nevertheless characterised the incidence of mental illness in Aboriginal and Torres Strait Islander communities as a “widespread”, “common and crippling problem which goes undiagnosed, unnoticed, and untreated”.⁶² The NSW Department of Health has also raised concern over the high rates of depression, suicide, substance misuse and mental illness-related hospitalisation for Indigenous Australians.⁶³

The best available data illustrating these concerns can be found in the report by the AIHW, which relies on information regarding hospitalisations and deaths in custody.⁶⁴ The report states that Indigenous Australians were twice as likely to be hospitalised for mental and behavioural disorders as other Australians. In particular, hospitalisations due to psychoactive substance abuse among male and female Indigenous Australians were around four and three times those for other male and female Australians, respectively. The report also states that as incarceration separates Indigenous people from their communities, many Indigenous prisoners experience depressive symptoms that can result in suicide attempts.

It is worth noting that the 2004–05 National Aboriginal and Torres Strait Islander Health Survey collected information relating to the health of Indigenous Australians. The survey has been carried out by the ABS in urban, rural and remote areas of Australia and results are expected to be available in 2006.

Welfare status

Drawing on data from the NSMHW on high prevalence mental illnesses, Butterworth estimated the prevalence of mental disorders among income support recipients.⁶⁵ The key findings were striking, in that almost one in three (more than 30%) income support recipients have an anxiety, affective or substance use disorder. This is 66% more than the prevalence of mental illness among Australians not receiving income support. The prevalence of clinical anxiety and depressive disorders among sole mother income recipients is between three and four times the national average, with 45% of these experiencing a diagnosable mental disorder. The report noted that mental illness can be a significant barrier to workforce participation and that people with mental illness are among the most disadvantaged in our society.

Demographic characteristics of adults with psychotic disorders⁶⁶

As noted above, the low prevalence/psychotic disorders component of the NSMHW did not collect any data in NSW; therefore, only national data are outlined here. Jablensky et al. report that the extreme disadvantage experienced by people with a psychotic mental illness is evidenced in the disproportionately high prevalence of unemployment and relative poverty, which “are widespread among people with psychotic disorders”.⁶⁷ Interestingly, almost half of those with psychotic illnesses had not completed their schooling or gained any post-school qualification, and 72% were unemployed. In the 12 months prior to the interview, only one in five had been involved in part-time work and less than 10% had been in full-time employment. Of those who reported some occupation, including housework or studying, almost half had experienced a serious or moderate degree of dysfunction in the performance of such activities. The majority of those surveyed were living in relative poverty: 85.2% were recipients of a pension or other form of welfare benefits, and only 15.5% had any income from employment or other independent sources.

In terms of accommodation, the majority of those surveyed (44.7%) were

living in institutions, hostels, group homes or other supported housing, and one-quarter of this group (11.3% of the total sample) were practically homeless or living in very marginal accommodation (living in marginal supported housing, rooming houses, hotel/rented rooms, crisis shelters, or were homeless or of no fixed address).⁶⁸

Almost one-third of participants (31%) were living alone. As to marital status, the majority (64%) were single and had never married (77% of men and 44% of women) and 21% reported to be separated, divorced or widowed.