The mental health of Australians 2

2.3 Impact of mental disorders

Page last updated: May 2009

2.3.1 Days out of role
2.3.2 Severity of mental disorders
2.3.3 Psychological distress

One of the key aims of the survey was to determine the impact of mental disorders on the Australian population - that is how disabling mental disorders are and how they affect people's functioning and day-to-day lives. A number of measures were included in the survey to provide this information. These include days out of role, measures of the severity of mental disorders and a measure of psychological distress, the Kessler 10 scale (K10).

2.3.1 Days out of role

Days out of role is a count of the number of days in the 30 days prior to interview that a person was unable to fulfil their usual role due to problems with their health. This covers the range of activities that the person usually performs (see glossary for further information). The average number of days out of role for people with mental disorders is shown in figure 2-2.

On average, people with mental disorders experienced four out of the previous 30 days out of role. This means that for those four days they were unable to carry out their normal activities or had to cut down on what they did. People with anxiety disorders experienced an average of four days out of role. People with substance use disorders experienced an average of three days out of role and people with affective disorders experienced an average of about six days out of role.

Figure 2-2: Days out of role by 12-month mental disorder class

Refer to the following text for a text equivalent of Figure 2-2: Days out of role by 12-month mental disorder class

Text version of figure 2-2

Figures in this description are approximate as they have been read from the graph.

Mean days out of role in previous 30 day period by mental disorder class:
  • Affective disorders - 6.2
  • Anxiety disorders - 4.4
  • Substance use disorders - 3.3
  • Any mental disorder - 3.8
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2.3.2 Severity of mental disorders

The severity of impairment associated with mental illness has important implications for the treatment of mental disorders, determining access to some services.

The measure of severity used in the survey summarises the impact of all the mental disorders experienced in a 12-month period on a person's daily life and categorises this impact as severe, moderate or mild. For additional information on severity refer to the glossary.

In terms of the total population, 4.1% or over 650,000 people had severe mental disorders in the previous 12 months, 6.6% or over one million people had moderate mental disorders and 9.3% or almost one and a half million people had mild mental disorders.

Of the one in five (20.0%) Australians aged 16-85 years who experienced mental disorders in the previous 12 months, one-fifth (20.5%) were classified as severe, one third (33.2%) were classified as moderate and just under half (46.3%) were classified as mild.

People with affective disorders were more likely to be categorised as having severe mental disorders compared to people with anxiety or substance use disorders (figure 2-3). Among people with affective disorders, half (51.1%) were classified as severe, compared to just over one-fifth (22.2%) with anxiety disorders and one-fifth (20.6%) with substance use disorders. One in ten (10.2%) people with affective disorders had mild mental disorders, compared to 43.8% of people with anxiety disorders and 54.6% of people with substance use disorders.

Figure 2-3: Proportion of people with 12-month mental disorders by mental disorder class and severity level

Refer to the following text for a text equivalent of Figure 2-3: Proportion of people with 12-month mental disorders by mental disorder class and severity level'

Text version of figure 2-3

Figures in this description are approximate as they have been read from the graph.
Mental disorder classSevereModerateMild
Affective disorders
51
39
10
Anxiety disorders
22
34
44
Substance use disorders
21
25
54
Any mental disorder
21
33
46
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2.3.3 Psychological distress

Psychological distress was measured using the Kessler 10 scale (K10). K10 scores were divided into four categories representing low psychological distress (scores ranging from 10-15), moderate psychological distress (scores ranging from 16-21), high psychological distress (scores ranging from 22-29) and very high psychological distress (scores ranging from 30-50) (figure 2-4).

The average K10 score for people with any 12-month mental disorder was 19.1, which is rated as moderate psychological distress, compared to a score of 13.3 or low psychological distress for people who did not have a mental disorder in the previous 12 months.

Almost one quarter (22.2%) of people with affective disorders reported very high psychological distress, compared to 11.9% of people with anxiety disorders and 7.3% of people with substance use disorders.

Figure 2-4: Proportion of people with 12-month mental disorders by mental disorder class and psychological distress (K10) level

Refer to the following text for a text equivalent of Figure 2-4: Proportion of people with 12-month mental disorders by mental disorder class and psychological distress (K10) level

Text version of figure 2-4

Figures in this description are approximate as they have been read from the graph.
Mental disorder classVery high psychological distressHighModerateLow
Affective disorders
22
31
28
19
Anxiety disorders
12
21
33
34
Substance use disorders
8
17
27
48
Any 12 month mental disorder
11
20
31
38
No 12 month mental disorder
1
3
17
79