Appendix 1 - Definitions of mental health and mental illness

Appendix 1 - Definitions of mental health and mental illness

Mental health

1.1      The National Mental Health Plan 2003-2008 (the Plan) declares that 'mental health is not simply the absence of mental illness' and defines mental health as:

[A] state of emotional and social wellbeing in which the individual can cope with the normal stresses of life and achieve his or her potential'.[2008]

1.2      The World Health Organisation (WHO) defines mental health as:


Mental illness

1.3      The Plan defines mental illness as:

...[a] mental illness is a clinically diagnosable disorder that significantly interferes with an individual's cognitive, emotional or social abilities.[2010]

1.4      Diagnoses of mental illnesses conform to classifications listed in two professional publications: the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition (DSM-IVR); and the International Classification of Diseases, Tenth Edition (ICD-10).[2011] The DSM-IVR covers mental illnesses and the ICD-10 covers mental and physical illnesses.

International Classification of Diseases

1.5      The ICD-10 was endorsed by the Forty-third World Health Assembly in May 1990 and came into use in WHO Member States from 1994. It 'has become the international standard diagnostic classification for all general epidemiological and many health management purposes'.[2012]


1.7      The ICD-10 recognises the following mental illnesses:[2014]

The Diagnostic and Statistical Manual of Mental Disorders

1.8      The DSM-IVR uses a multiaxial or multidimensional approach to diagnosis because rarely do other factors in a person's life not impact their mental health. It describes five dimensions, or axes:[2015]

Axis I: Clinical Syndromes
Axis II: Developmental Disorders and Personality Disorders
Axis IV: Severity of Psychosocial Stressors
Axis V: Highest Level of Functioning

1.9      It is clear from the above that the DSM-IVR describes three main types of mental disorder, namely, clinical syndromes, development disorders and personality disorders. Other factors included in the axes, for example, physical conditions and psychosocial stressors, are not mental health disorders in themselves but are considered to have an important impact on the disorders described in Axis I and II.

1.10         The DSM-IVR describes the following disorders:[2016]

Adjustment Disorders

1.11         All of the disorders in this category relate to a significantly more difficult adjustment to a life situation than would normally be expected considering the circumstances. While it is common to need months, and perhaps even years, to feel normal again after the loss of a long-time spouse, for instance, when this adjustment causes significant problems for an abnormal length of time it may be considered an adjustment disorder.

Disorders in this Category
Anxiety Disorders

1.12         Anxiety Disorders categorise a large number of disorders where the primary feature is abnormal or inappropriate anxiety. Everybody has experienced anxiety. Chances are you experienced an increased heart rate, tensed muscles, and perhaps an acute sense of focus as you tried to determine the source of a noise. These are all symptoms of anxiety. They are also part of a normal process in our bodies called the 'flight or flight' phenomenon. These symptoms become a problem when they occur without any recognisable stimulus or when the stimulus does not warrant such a reaction.

Disorders in this Category
Dissociative Disorders

1.13         The main symptom cluster for dissociative disorders includes a disruption in consciousness, memory, identity, or perception. In other words, one of these areas is not working correctly and causing significant distress within the individual.

Disorders in this Category
Eating Disorders

1.14         Eating disorders are characterised by disturbances in eating behaviour. This can mean eating too much, not eating enough, or eating in an extremely unhealthy manner (such as binging or stuffing yourself over and over). Many people argue that simple overeating should be considered a disorder, but at this time it is not in this category.

Disorders in this Category
Impulse-Control Disorders

1.15         Disorders in this category include the failure or extreme difficulty in controlling impulses despite the negative consequences. This includes the failure to stop gambling even if you realise that losing would result in significant negative consequences. This failure to control impulses also refers to the impulse to engage in violent behaviour (e.g., road rage), sexual behaviour, fire starting, stealing, and self-abusive behaviours.

Disorders in this Category
Mood Disorders

1.16         The disorders in this category include those where the primary symptom is a disturbance in mood. In other words, inappropriate, exaggerated, or a limited range of feelings. Everybody gets down sometimes, and everybody experiences a sense of excitement and emotional pleasure. To be diagnosed with a mood disorder, your feelings must be in the extreme. In other words, crying, and/or feeling depressed or suicidal frequently. Or having excessive energy where sleep is not needed for days at a time, and decision making processes are significantly hindered.

Disorders in this Category
Sexual Disorders

1.17         Paraphilias all have in common distressing and repetitive sexual fantasies, urges, or behaviours. These fantasies, urges, or behaviours must occur for a significant period of time and must interfere with either satisfactory sexual relations or everyday functioning if the diagnosis is to be made. There is also a sense of distress within these individuals. In other words, they typically recognise the symptoms as negatively impacting their life but feel as if they are unable to control them.

Disorders in this Category
Sleep Disorders

1.18         Primary sleep disorders are divided into two subcategories: Dyssomnias are those disorders relating to the amount, quality, and timing of sleep. Parasomnias relate to abnormal behaviour or physiological events that occur during the process of sleep or sleep-wake transitions. The term 'primary' is used to differentiate these sleep disorders from other sleep disorders that are caused by outside factors, such as another mental disorder, medical disorder, or substance use. The primary sleep disorders are listed below:

Disorders in this Category
Psychotic Disorders

1.19         The major symptom of these disorders is psychosis, or delusions and hallucinations. Delusions are false beliefs that significantly hinder a person's ability to function. For example, believing that people are trying to hurt you when there is no evidence of this, or believing that you are somebody else, such as Jesus Christ or Cleopatra. Hallucinations are false perceptions. They can be visual (seeing things that aren't there), auditory (hearing), olfactory (smell), tactile (feeling sensations on your skin that aren't really there, such as insects crawling on you), or taste.

Disorders in this Category
Sexual Dysfunctions

1.20         The primary characteristic in this category is the impairment in normal sexual functioning. This can refer to an inability to perform or reach an orgasm, painful sexual intercourse, a strong repulsion of sexual activity, or an exaggerated sexual response cycle or sexual interest. A medical cause must be ruled out prior to making any sexual dysfunction diagnosis and the symptoms must be hindering the person's everyday functioning.

1.21         Gender Identity Disorder has also been placed in this category, although no outward dysfunction needs to be present for this disorder. Basically, it includes strong feelings of being the wrong gender, or feelings that your outward body is inconsistent with your internal sense of being either male or female.

Disorders in this Category
Somatoform Disorders

1.22         Disorders in this category include those where the symptoms suggest a medical condition but where no medical condition can be found by a physician. In other words, a person with a somatoform disorder might experience significant pain without a medical or biological cause, or they may constantly experience minor aches and pains without any reason for these pains to exist.

Disorders in this Category
Substance Disorders

1.23         The two disorders in this category refer to either the abuse of, or dependence on, a substance. A substance can be anything that is ingested in order to produce a high, alter one's senses, or otherwise affect functioning. The most common substance used is alcohol although other drugs, such as cocaine, marijuana, heroin, ecstasy, special-K, and crack, are included. The most abused substances, caffeine and nicotine, are also included although these are rarely thought of in this manner by the layman.

Disorders in this Category
Personality Disorders


1.25         To be diagnosed with a disorder in this category, a psychologist will look for the following criteria:

Disorders in this Category

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