2.2 Diagnostic criteria for autism
Profiles of characteristics necessary for a diagnosis of classic autism or an ASD are called diagnostic criteria . These criteria appear within general systems for the classification and diagnosis of psychological problems such as the Diagnostic and Statistical Manual prepared by the American Psychiatric Association (last revised in 2000 and known as DSM-IV-TR™), and the International Classification of Diseases, prepared by the World Health Organization (currently in its tenth edition and known as ICD-10).
We will first look at the diagnostic criteria for ‘classic’ autism. In Section 3 of this course we will highlight the way this ‘classic’ picture must be modified to take into account varying symptom patterns across the spectrum.
Box 1: Diagnostic criteria for classic autism according to DSM-IV-TR™
A A total of six (or more) items from (1), (2) and (3), with at least two from (1), and one each from (2) and (3):
Qualitative impairment in social interaction, as manifested by at least two of the following:
(a) Marked impairment in the use of multiple nonverbal behaviours such as eye-to-eye gaze, facial expression, body postures, and gestures to regulate social interaction.
(b) Failure to develop peer relationships appropriate to developmental level.
(c) A lack of spontaneous seeking to share enjoyment, interests, or achievements with other people (e.g. by a lack of showing, bringing or pointing out objects of interest).
(d) Lack of social or emotional reciprocity.
Qualitative impairments in communication as manifested by at least one of the following:
(a) Delay in, or total lack of, the development of spoken language (not accompanied by an attempt to compensate through alternative modes of communication such as gesture or mime).
(b) In individuals with adequate speech, marked impairment in the ability to initiate or sustain a conversation with others.
(c) Stereotyped and repetitive use of language or idiosyncratic language.
(d) Lack of varied, spontaneous make-believe play or social imitative play appropriate to developmental level.
Restricted repetitive and stereotyped patterns of behaviour, interests, and activities, as manifested by at least one of the following:
(a) Encompassing preoccupation with one or more stereotyped and restricted patterns of interest that is abnormal either in intensity or focus.
(b) Apparently inflexible adherence to specific, non-functional routines or rituals.
(c) Stereotyped and repetitive motor mannerisms (e.g. hand or finger flapping or twisting, or complex whole-body movements).
(d) Persistent preoccupation with parts of objects.
B Delays or abnormal functioning in at least one of the following areas, with onset prior to age 3 years: (a) social interaction, (b) language as used in social communication, (c) symbolic or imaginative play.
C The disturbance is not better accounted for by Rett's Disorder or Childhood Disintegrative Disorder.*
* Rett's Disorder and Childhood Disintegrative Disorder are syndromes with some symptoms overlapping with autism. Discussion is beyond the scope of this course.
Diagnostic criteria : A formally agreed profile of symptoms and characteristics, typifying a syndrome or disorder, used in diagnosis.
Reflect on the four accounts of autism at the beginning of this course in light of the diagnostic criteria. Make a list of those diagnostic criteria represented in the different accounts, and compare your list to the discussion below.
Christopher: lack of eye contact and loss of language indicating qualitative impairments in communication (Area 2) and possibly a lack of social reciprocity (Area 1). Symptoms developed below 36 months.
Alison: ‘living in own world’ suggesting qualitative impairments in both social interaction (Area 1, particularly not sharing interests, lack of social reciprocity) and communication (Area 2, apparently she does not speak). Rocking indicates repetitive activities, and musical interests could reflect a preoccupation (Area 3).
Gunilla: her rather idiosyncratic understanding and use of language could reflect a subtle communication impairment (Area 2). However her difficulties, which are not well captured by the diagnostic criteria, probably reflect a less severe spectrum disorder – see Section 3 .
Tito: fascination with calendars suggests a preoccupation (Area 3). However, his command of language to describe this obsession seems at odds with several criteria in Area 2. Tito also has areas of outstanding talent – especially poetry, which fits with the descriptions of ‘savant’ skills in Sections 2.3 and 3.3 . He is almost certainly in the small minority of individuals whose autism goes together with ‘savant syndrome’.