Australian Bureau of Statistics
Celebrating the International Year of Statistics 2013

APPENDIX 1 ICD–10 DIAGNOSES


OVERVIEW

This Appendix presents descriptions of the diagnostic algorithms devised for the World Mental Health Survey Initiative version of the World Health Organization's Composite International Diagnostic Interview, version 3.0 (WMH-CIDI 3.0). Diagnostic algorithms are specified in accordance with the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition (DSM-IV) and the WHO International Classification of Diseases, Tenth Revision (ICD-10) classification systems. As not all modules contained in the WMH-CIDI 3.0 were operationalised for the 2007 SMWHB, it was necessary to tailor the diagnostic algorithms to fit the Australian context.

Throughout this publication, mental disorder diagnosis is presented according to the ICD-10 criteria. Detailed information on the diagnosis of mental disorders according to the DSM-IV criteria will be available in the National Survey of Mental Health and Wellbeing, Users' Guide, 2007 (cat. no. 4327.0) planned for release on the ABS website <www.abs.gov.au> in late 2008 .


ASSESSMENT OF DIAGNOSTIC CRITERIA

Diagnostic criteria usually involve specification of the following:

• the nature, number and combination of symptoms required
• the level of distress or impairment required
• exclusion of a diagnosis due to symptoms being directly attributed to a general medical condition or substance use
• exclusion of a diagnosis where the criteria are met for a related disorder (eg Generalised Anxiety Disorder cannot be diagnosed where criteria are met for Obsessive-Compulsive Disorder).

HIERARCHY RULES

The classification system for some of the ICD-10 disorders contain diagnostic exclusion rules so that a person, despite having symptoms that meet diagnostic criteria, will not meet criteria for particular disorders because the symptoms are believed to be accounted for by the presence of another disorder. In these cases, one disorder takes precedence over another. These exclusion rules are built into the diagnostic algorithms.

The developers of WMH-CIDI 3.0 established two versions of the diagnoses in the algorithms for a number of the mental disorders: a 'with hierarchy' version and a 'without hierarchy' version. The 'with hierarchy' version specifies the full diagnostic criteria consistent with the ICD-10 classification system (ie the exclusion criteria are enforced). The 'without hierarchy' version applies all diagnostic criteria except the criterion specifying the hierarchical relationship with other disorders.

One example of a disorder specified with and without hierarchy is Alcohol Harmful Use. ICD-10 states that in order for diagnostic criteria for Harmful Use to be met, criteria cannot be met for Dependence on the same substance during the same time period. Therefore, the ‘with hierarchy’ version of Alcohol Harmful Use will exclude cases where Alcohol Dependence has been established for the same time period. The ‘without hierarchy’ version includes all cases of Alcohol Harmful Use regardless of coexisting Alcohol Dependence. Note that a person can meet criteria for Alcohol Dependence and the hierarchical version of Alcohol Harmful Use if there is no overlap in time between the two disorders.

Throughout this publication, the ICD-10 prevalence rates are presented with the hierarchy rules applied. The comorbidity data are presented without hierarchy, so as to provide a more complete picture of the combinations of symptoms and disorders experienced by individuals. The ICD-10 disorders specified with and without hierarchy are: Generalised Anxiety Disorder; Hypomania; Mild, Moderate and Severe Depressive Episode; Dysthymia; and the Harmful Use of Alcohol, Cannabis, Sedatives, Stimulants and Opioids.


MENTAL DISORDERS

ANXIETY DISORDERS

Anxiety disorders generally involve feelings of tension, distress or nervousness. A person may avoid, or endure with dread, situations which cause these types of feelings. The disorders within this group assessed in this survey are: Panic Disorder, Agoraphobia, Social Phobia, Generalised Anxiety Disorder (GAD), Obsessive-Compulsive Disorder (OCD) and Post-Traumatic Stress Disorder (PTSD).

Panic Disorder

A panic attack is a discrete episode of intense fear or discomfort that starts abruptly and reaches a peak within a few minutes and lasts at least some minutes. At least four symptoms must be present from the list below, one of which must be from the first four:

• pounding heart
• sweating
• trembling or shaking
• dry mouth
• difficulty breathing
• feeling of choking
• chest pain or discomfort
• nausea or abdominal distress
• dizziness or light-headed
• feelings of unreality or depersonalisation
• fear of passing out or losing control
• fear of dying,
• hot flushes or cold chills
• numbness or tingling sensations

The essential feature of Panic Disorder is recurrent attacks of severe anxiety (panic), which are not restricted to any particular situation or set of circumstances (ie do not occur in the presence of a phobia, or in situations of danger) and are therefore unpredictable.

Agoraphobia

Characterised by marked and consistently manifest fear in, or avoidance of, at least two of the following situations:

• crowds
• public places (ie using public transport; standing in a line in a public place; being in a department store, shopping centre, or supermarket; being in a movie theatre auditorium, lecture hall, or church; being in a restaurant or any other public place)
• travelling alone (ie travelling alone or being alone away from home)
• travelling away from home

At least two of the following anxiety symptoms must have been present together with the feared situation and one of these symptoms must be from the first four listed:

• pounding heart
• sweating
• trembling or shaking
• dry mouth
• difficulty breathing
• feeling of choking
• chest pain or discomfort
• nausea or abdominal distress
• feeling dizzy or light-headed
• feelings of unreality or depersonalisation
• fear of passing out, or losing control
• fear of dying,
• hot flushes or cold chills
• numbness or tingling sensations

The person also experiences significant emotional distress due to the avoidance or the anxiety symptoms and recognises that these are excessive or unreasonable.

Social Phobia

Characterised by fear and/or avoidance of one or more social or performance situations such as:

• meeting new people
• talking to people in authority
• speaking up in a meeting or class
• going to social gatherings
• performing in front of an audience
• taking an important exam
• working while someone watches
• entering a room when others are present
• talking with people who they don't know very well
• disagreeing with people
• writing or eating or drinking while someone watches
• using a public bathroom
• dating
• social or performance situation

The presence of Social Phobia is also characterised by:

• The fear of either being the focus of attention or of behaving in a way that will be embarrassing or humiliating; or the avoidance of either being the focus of attention, or of situations where there is fear of behaving in an embarrassing or humiliating way.
• At least two anxiety symptoms (from the list in Agoraphobia above) must be present in the feared situation at some time since the onset of the disorder, together with at least one of the following: blushing or shaking; nausea or fear of vomiting; or the urgency or fear of losing control of bowels or bladder.
• Significant distress caused by the symptoms or by the avoidance and the person recognises that these are excessive or unreasonable.

Generalised Anxiety Disorder

Characterised by a period of at least six months with tension, worry and apprehension about everyday events and problems. The disorder is not due to a physical disorder or substance use. At least four of the following symptoms must be present, with at least one of the first four:

• pounding heart
• sweating
• trembling or shaking
• dry mouth
• difficulty breathing
• feeling of choking
• chest pain
• nausea, stomach pain or discomfort
• dizziness
• feelings of unreality or depersonalisation
• fear of losing control or passing out
• fear of dying
• hot flushes or cold chills
• numbness or tingling sensations
• muscle tension or aches and pains
• restlessness
• feeling on edge
• a sensation of a lump in the throat
• exaggerated response to minor surprises
• difficulty concentrating
• irritability
• trouble in getting to sleep because of worry

Hierarchy rules have been applied to Generalised Anxiety Disorder. To meet criteria for the 'with hierarchy' version:

- the Generalised Anxiety Disorder does not occur exclusively within the duration of Panic Disorder; and
- the Generalised Anxiety Disorder is not exclusively associated with social and performance situations (ie Social Phobia); and
- the Generalised Anxiety Disorder does not occur exclusively within the duration of (and is not exclusively associated with) obsessions and compulsions (ie Obsessive-Compulsive Disorder).

The original exclusion rules from the ICD-10 also consider the presence of other phobic disorders and hypochondriacal disorder. As the 2007 SMHWB did not collect information for Specific Phobia or Hypochondriacal Disorder, the Generalised Anxiety Disorder prevalence may include some persons with these disorders.

Obsessive-Compulsive Disorder

Either obsessions or compulsions (or both) are present on most days for at least two weeks. Obsessions (thoughts, ideas or images) and compulsions (acts) share the following features, all of which must be present:

• repetitive and unpleasant, and at least one obsession or compulsion is acknowledged as excessive or unreasonable;
• the person tries to resist them, and at least one obsession or compulsion that is unsuccessfully resisted must be present; and
• the person derives no pleasure from the obsessive thought or compulsive act;
• the obsessions or compulsions cause distress or interfere with the person's social or individual functioning;
• the respondent considers that the obsessions and compulsions do not occur exclusively within episodes of depression (ie this is based on self report by the respondent, not according to diagnosis made by the CIDI).

Post-Traumatic Stress Disorder

Characterised by symptoms experienced within six months of exposure to an extremely traumatic event which would be likely to cause pervasive distress in almost anyone. In order to be assessed for this disorder, the respondent had to have reported experiencing at least one of the following traumatic events:

• direct combat experience in a war
• a war or ongoing terror as a peacekeeper
• a war as an unarmed civilian
• living in a place with ongoing terror
• ever being a refugee
• being kidnapped or held captive
• being exposed to a toxic substance
• a life-threatening car accident
• a life threatening accident
• a fire, flood or other natural disaster
• a man-made disaster or bomb explosion
• a life-threatening illness
• being beaten as a child
• being beaten by a spouse or partner
• being beaten by anyone else
• being held up or threatened with a weapon
• rape
• sexual molestation
• being stalked
• an unexpected death at a young age of someone very close
• a son or daughter with a life-threatening illness or injury
• traumatic experience (rape) of someone very close
• witness serious physical fights at home as a child
• someone being badly injured or killed, or unexpectedly seeing a dead body
• doing something that accidentally led to serious injury or death of another person
• seriously injure, torture or kill another person on purpose
• witnessing atrocities
• any other extremely traumatic or life-threatening events
• any other extremely traumatic or life-threatening events including events the respondent does not wish to describe

The respondent was asked to determine which event was their worst traumatic event. To meet the criteria for this disorder, the person must report all of the following reactions to their worst traumatic event:

• The traumatic event is persistently remembered or relived (eg flashbacks, dreams, or distress when reminded of the event), or the person experiences distress when exposed to circumstances resembling or associated with the event;
• The person exhibits an actual or preferred avoidance of circumstances resembling or associated with the event, which was not present before that event;
• The person exhibits either an inability to recall some or all aspects of the trauma or two or more symptoms of increased sensitivity and arousal (difficulty in falling or staying asleep; irritability; difficulty concentrating; hypervigilance; exaggerated startle response).

AFFECTIVE DISORDERS

Affective disorders involve mood disturbance, or change in affect. Most of these disorders tend to be recurrent and the onset of individual episodes can often be related to stressful events or situations. Disorders within this group include: Depressive Episode, Dysthymia and Bipolar Affective Disorder (of which Hypomania and Mania are components).

Hypomania

Hypomania is characterised by elevated or irritable mood to a degree that is abnormal for the individual concerned and sustained for at least four consecutive days. It leads to some interference with daily living but to a lesser degree than Mania. At least three of the following symptoms must be present:

• increased activity or restlessness
• increased talkativeness
• distractibility
• decreased need for sleep
• increased sexual energy
• overspending or other types of reckless or irresponsible behaviour
• over-familiarity or increased sociability

Hierarchy rules have been applied to Hypomania. To meet criteria for the 'with hierarchy' version, the person cannot have met criteria for an episode of Mania in their lifetime.

The original exclusion rules from the ICD-10 also consider the presence of any Depressive Episodes, Cyclothymia and Anorexia Nervosa. As the 2007 SMHWB did not collect information for Cyclothymia or Anorexia Nervosa (and the presence of Depressive Episodes was not operationalised by the diagnostic algorithm), Hypomania may include some persons with these disorders.

Mania

Mood is elevated, expansive or irritable and definitely abnormal for the person concerned. The episode lasts for at least seven days (unless the episode is severe enough to require hospitalisation), causes severe interference with personal functioning, is not directly caused by substance use or a physical condition, and is characterised by at least three of the following (four if the mood is merely irritable):

• increased activity or restlessness
• increased talkativeness
• flight of ideas or the feeling that thoughts are racing
• loss of normal social inhibitions
• decreased need for sleep
• inflated self-esteem or grandiosity
• distractibility
• reckless behaviour
• marked sexual energy or sexual indiscretions

Depressive Episode

A Depressive Episode lasts for at least two weeks and is characterised by the presence of a number of the following symptoms:

• depressed mood
• loss of interest in activities
• lack of energy or increased fatigue
• loss of confidence or self esteem
• feelings of self-reproach or excessive guilt
• thoughts of death or suicide, or suicide attempts
• diminished ability to concentrate, think or make decisions
• change in psychomotor activity; agitation or retardation
• sleep disturbance
• change in appetite

The survey collected information to differentiate between three different types of Depressive Episode, based on the number of symptoms the person experienced:

• Severe Depressive Episode - all of the first three symptoms from the above list and additional symptoms from the remainder of the list to give a total of at least eight.
• Moderate Depressive Episode - at least two of the first three symptoms from the above list and additional symptoms from the remainder of the list to give a total of at least six.
• Mild Depressive Episode - at least two of the first three symptoms from the above list and additional symptoms from the remainder of the list to give a total of at least four.

Hierarchy rules have been applied to all of the Depressive Episodes. To meet criteria for the 'with hierarchy' versions, the person cannot have met criteria for either Hypomanic or Manic episodes in their lifetime.

The three types of Depressive Episode collected by the 2007 SMHWB are also mutually exclusive. A person cannot be diagnosed with Moderate Depressive Episode if the criteria for a Severe Depressive Episode have already been met and a diagnosis of a Mild Depressive Episode is considered only when the other two types of depression have been excluded. This criteria is applied regardless of whether the 'with hierarchy' or 'without hierarchy' versions of the disorder is used.

Dysthymia

A disorder characterised by at least two years of constant (or constantly recurring) chronic depressed mood, where intervening periods of normal mood rarely last for longer than a few weeks.

During some of the periods of depression at least three of the following are present:

• reduced energy or activity
• insomnia
• loss of self-confidence or feeling inadequate
• difficulty in concentrating
• frequent tearfulness
• loss of interest in or enjoyment of sex and other pleasurable activities
• feeling of hopelessness or despair
• feeling unable to cope with everyday responsibilities
• pessimism about the future or brooding over the past
• social withdrawal
• reduced talkativeness

Hierarchy rules have been applied to Dysthymia. To meet criteria for the 'with hierarchy' version:

• the person must not have met criteria for either Hypomanic or Manic episodes in their lifetime; and
• there must be no episodes of Severe or Moderate Depression identified within the first two years of Dysthymia.

Bipolar Affective Disorder

Characterised by episodes of Mania or Hypomania either alone or in conjunction with Depressive Episodes. For this survey, a diagnosis of Bipolar Affective Disorder was given if the person met criteria for Mania or Hypomania and had experienced one episode of mood disturbance (Mania, Hypomania or Depression). The survey does not allow differentiation according to the type of the current episode.


SUBSTANCE USE DISORDERS

Substance Use Disorders involve the Harmful Use and/or Dependence on alcohol and/or drugs. The misuse of drugs, defined as the use of illicit substances and the misuse of prescribed medicines, included the following drug categories: opioids, cannabinoids, sedatives, and stimulants.


Alcohol Use Disorders

Detailed questions about alcohol use were only asked if the person had at least 12 alcoholic drinks in the 12 months prior to interview.

Alcohol Harmful Use

There is clear evidence that the use of alcohol was responsible for (or substantially contributed to) physical or psychological harm, including impaired judgement or dysfunctional behaviour which may lead to disability or have adverse consequences for interpersonal relationships.

The nature of the harm should be clearly identifiable by including at least one of the following:

• frequent interference with work or other responsibilities
• causing arguments or other serious problems with family, friends, neighbours or co-workers
• jeopardising safety because of alcohol use
• being arrested or stopped by police for drunk driving or drunk behaviour.

Hierarchy rules have been applied to Alcohol Harmful Use. To meet criteria for the 'with hierarchy' version, a person cannot have met a diagnosis of Alcohol Dependence during the same time period (ie the duration of the two disorders must not overlap).

Alcohol Dependence Syndrome

A maladaptive pattern of behaviour in which the use of alcohol takes on a much higher priority for a person than other behaviours that once had greater value. The central characteristic is the strong, sometimes overpowering, desire to consume alcohol despite significant alcohol-related problems. A diagnosis was achieved if three or more of the following occurred within the same year:

• strong desire or compulsion to consume alcohol
• difficulties in controlling alcohol consumption behaviour
• withdrawal symptoms (eg fatigue, headaches, diarrhoea, the shakes or emotional problems)
• tolerance to alcohol (eg needing to drink a larger amount for the same effect)
• neglect of alternative interests because of alcohol use
• continued use despite knowing it is causing significant problems.

Drug Use Disorders

Assessment for Harmful Use and Dependence was only conducted if use of an illicit drug or misuse of a prescription medication occurred more than five times in the respondents' lifetime. A general assessment was made for Harmful Use and Dependence of any drugs as well as separate assessments of Harmful Use and Dependence for four specific categories of drug categories: opioids (eg heroin, methadone, opium); cannabiniods (eg marijuana, hashish); sedatives (eg barbiturates, librium, serepax, sleeping pills, valium); and stimulants (eg amphetamines, dexedrine, speed).

Other Substance Harmful Use

This survey collected information on:

• Harmful Use - opioids
• Harmful Use - cannabinoids
• Harmful Use - sedatives
• Harmful Use - stimulants

There is clear evidence that the use of opioids/cannabinoids/sedatives/stimulants were responsible for (or substantially contributed to) physical or psychological harm, including impaired judgement or dysfunctional behaviour which may lead to disability or have adverse consequences for interpersonal relationships.

The nature of the harm should be clearly identifiable by including at least one of the following:

• frequent interference with work or other responsibilities
• causing arguments or other serious problems with family, friends, neighbours or co-workers
• jeopardising safety because of substance use
• being arrested or stopped by police for driving while intoxicated or other behaviour while intoxicated.

Hierarchy rules have been applied to Other Substance Harmful Use. To meet criteria for the 'with hierarchy' versions, a person cannot have met a diagnosis of Dependence on the same substance during the same time period (ie the duration of the two disorders must not overlap).

Other Substance Dependence Syndrome

This survey collected information on:

• Dependence Syndrome - opioids
• Dependence Syndrome - cannabinoids
• Dependence Syndrome - sedatives
• Dependence Syndrome - stimulants

Opioids/cannabinoids/sedatives/stimulants Dependence Syndrome is a maladaptive pattern of substance use in which the use of the substance takes on a much higher priority for a person than other behaviours that once had greater value. The central characteristic is the strong, sometimes overpowering, desire to take the substance despite significant substance-related problems. Diagnoses were achieved if three or more of the following occurred in the 12 months prior to interview:

• strong desire or compulsion to take the substance
• difficulties in controlling substance-taking behaviour
• withdrawal symptoms (eg fatigue, headaches, diarrhoea, the shakes or emotional problems)
• tolerance to the drug (eg needing to use a larger amount for the same effect)
• neglect of alternative interests because of substance use
• continued use despite knowing it is causing significant problems.