Criteria that define a ‘mental disorder’
At what point does a ‘problem of daily living’, or a ‘characteristic human trait’ (which may lie along the spectrum or continuum of human behaviour) become a ‘diagnosable disorder’ or a ‘disease’? When it interferes with an individual’s quality of life and causes them distress? But can conditions that are referred to as ‘mental illnesses’ be truly considered to represent ‘diseases’ or ‘disorders’ in a physical sense with an underlying pathology that would qualify their classification as such? Or are they in fact personal, social and ethical problems associated with everyday living within societal and cultural contexts? Are they psychosocial constructs that reflect the complexity of human interactions, politics, poverty, unemployment, traumatic experiences, internal and external conflict, and the need to conform with societal ‘norms’ and socially acceptable behaviours?
Thomas Szasz, a psychiatrist and life-long critic of diagnostic classification systems wrote in his 1960 article on ‘The Myth of Mental Illness’:
The assumption is made that some neurological defect, perhaps a very subtle one, will ultimately be found for all the disorders of thinking and behavior… for those who regard mental symptoms as signs of brain disease, the concept of mental illness is unnecessary and misleading. For what they mean is that people so labeled suffer from diseases of the brain…
Fifty years on (in 2011), he wrote:
In due time, with refinements in medical technology, psychiatrists will be able to show that all mental illnesses are bodily diseases… This contingency does not falsify my contention that mental illness is a metaphor. It verifies it… Such a process of biological discovery has in fact, characterised some of the history of medicine, one form of ‘madness’ after another being identified as the manifestation of one or another somatic disease, such as beriberi or neurosyphilis. The result of such discoveries is that the illness ceases to be a form of psychopathology and is classified and treated as a form of neuropathology. If all the conditions now called mental illnesses proved to be brain diseases, there would be no need for the notion of mental illness and the term would become devoid of meaning.
Box 3 DSM-5 Criteria that define a condition as a mental disorder
(American Psychiatric Association, 2013)
A mental disorder is a syndrome characterized by clinically significant disturbance in an individual's cognition, emotion regulation, or behavior that reflects a dysfunction in the psychological, biological, or developmental processes underlying mental functioning.
Mental disorders are usually associated with significant distress or disability in social, occupational, or other important activities. An expectable or culturally approved response to a common stressor or loss, such as death of a loved one is not a mental disorder.
Socially deviant behavior (e.g. as political, religious or sexual) and conflicts that are primarily between the individual and society are not mental disorders unless the deviance or conflict results from a dysfunction within the individual, as described above.
The diagnosis of a mental disorder should have clinical utility. That is, it should:
help to determine prognosisa
help in the development of treatment plans
help to give an indication of potential treatment outcomes
A diagnosis of a mental disorder is not equivalent to a need for treatmenta
Need for treatment is a complex clinical decision that takes into consideration:
symptom salience (presence of relevant symptom; e.g. presence of suicidal ideation)
distress (mental pain) associated with the symptom(s)
disability related to the individual’s symptoms; risks and benefits of available treatment
other factors such as mental symptoms complicating other illness
Note [a] DSM-5 clarifies that the diagnosis of a mental disorder does not by itself indicate a need for treatment as outlined above.
For Sasz, the notion of mental illness and brain disease appear to be mutually exclusive. Others have argued that the concept of ‘disease’ can be understood in terms of suffering, functional impairment and incapacity, and ‘mental disorder’ conceptualised as transcending the mind-body dualism (Aftab, 2014). It is certainly not as clear-cut as this. Examples from medicine reinforce the point that the health of the body and of the mind are inextricably linked (Renoir et al., 2013), but with the emergence of biological psychiatry and modern advances in brain and behavioural sciences, most mental illnesses are increasingly presumed to have a neurobiological basis, even if that basis is, as yet, poorly understood. This does not address the issue that there is still no satisfactory definition for either ‘disease’ or ‘mental disorder’ which is universally accepted, and the term ‘mental disorder’ is misleading as it implies a distinction between a mental and a physical disorder. DSM-5 has attempted to define the criteria that should be met for a condition to be termed a ‘mental disorder’ (see Box 3).