Introduction

The 2007 National Survey of Mental Health and Wellbeing (NSMHWB) was designed to provide lifetime prevalence estimates for mental disorders.

Purpose

To gain statistics on key mental health issues including the prevalence of mental disorders, the associated disability, and the use of services.

As such the NSMHWB was a national epidemiological survey of mental disorders that used similar methodology to the NCS. It aimed to answer three main questions:

1. How many people meet DSM-IV and ICD-10 diagnostic criteria for the major mental disorders?
2. How disabled are they by their mental disorders? and
3. How many have seen a health professional for their mental disorder?

Background

Respondents were asked about experiences throughout their lifetime. In this survey, 12-month diagnoses were derived based on lifetime diagnosis and the presence of symptoms of that disorder in the 12 months prior to the survey interview. Assessment of mental disorders presented in this publication are based on the definitions and criteria of the World Health Organisation’s (WHO) International Classification of Diseases, Tenth Revision (ICD-10). Prevalence rates are presented with hierarchy rules applied (i.e. a person will not meet the criteria for particular disorders because the symptoms are believed to be accounted for by the presence of another disorder).

Results

• Among the 16,015,300 people aged 16-85 years, 45% (or 7,286,600 people) had a lifetime mental disorder (i.e. a mental disorder at some point in their life).
• More than half (55% or 8,728,700 people) of people had no lifetime mental disorders.
• Of people who had a lifetime mental disorder:
  • 20% (or 3,197,800 people) had a 12-month mental disorder and had symptoms in the 12 months prior to the survey interview; and
  • 25% (or 4,088,800 people) had experienced a lifetime mental disorder but did not have symptoms in the 12 months prior to the survey interview.

Prevalence of 12-Month Mental Health Disorders

Prevalence of mental disorders is the proportion of people in a given population who met the criteria for diagnosis of a mental disorder at a point in time

• Among the 3,197,800 people (or 20% of people) who had a 12-month mental disorder and had symptoms in the 12 months prior to interview:
  • 14.4% had a 12-month Anxiety disorder (includes Panic disorder (2.6%); Agoraphobia (2.8%); Social Phobia (4.7%); Generalised Anxiety Disorder (2.7%); Obsessive-Compulsive Disorder (1.9%); and Post-Traumatic Stress Disorder (6.4%))
  • 6.2% had a 12-month Affective disorder (includes Depressive Episode (4.1%) (includes severe, moderate and mild depressive episodes); Dysthymia (1.3%); and Bipolar Affective Disorder (1.8%)), and
  • 5.1% had a 12-month Substance Use Disorder (includes Alcohol Harmful Use (2.9%); Alcohol Dependence (1.4%); and Drug Use Disorders (includes harmful use and dependence) (1.4%)).
• Note that a person may have had more than one mental disorder.
  • The components when added may therefore not add to the total shown.
  • Includes Severe Depressive Episode, Moderate Depressive Episode, and Mild Depressive Episode.
  • Includes Harmful Use and Dependence.

There were 3.2 million people who had a 12-month mental disorder. In total, 14.4% (2.3 million) of Australians aged 16-85 years had a 12-month Anxiety disorder, 6.2% (995,900) had a 12-month Affective disorder and 5.1% (819,800) had a 12-month Substance Use disorder.

Women experienced higher rates of 12-month mental disorders than men (22% compared with 18%). Women experienced higher rates than men of Anxiety (18% and 11% respectively) and Affective disorders (7.1% and 5.3% respectively). However, men had twice the rate of Substance Use disorders (7.0% compared with 3.3% for women).

The prevalence of 12-month mental disorders varies across age groups, with people in younger age groups experiencing higher rates of disorder. More than a quarter (26%) of people aged 16-24 years and a similar proportion (25%) of people aged 25-34 years had a 12-month mental disorder compared with 5.9% of those aged 75-85 years old.

You can read the full survey results here and a shorter analysis can be found here.