Autistic Spectrum Disorders
Rajeshree Singhania MD, PhD, Med (Autism)
Autism has attracted a remarkable degree of interest and concern from clinicians and researchers alike, more so in recent times. It is a complex neurodevelopmental disorder that is behaviourally defined and is usually apparent from early childhood (Tuchman R, 2003, Volkmar, Sher & Cohen 1985). It is characterised by profound deficits in communication and social understanding and by ritualistic and obsessional behaviours (Howlin 1998). Wing (1996) postulated that people with autism are alike in that they share the triad of impairments that underlie the condition. The triad emphasises the fundamentally social nature of the disorder. There is a co-occurrence of impairments in social interaction, social communication and social imagination, flexible thinking and imaginative play.
A wide clinical spectrum:
The syndrome of autism can occur in individuals of all levels of ability and a tremendous range exists in the expression of the disorder. These diverse expressions within and across individuals present particular challenges for assessment and treatment.
Family studies point to a range of deficits, in first-degree relatives of autistic children in the following three areas – social dysfunction, communication impairment and stereotyped behaviour (Fombonne et al 1997). They identified lesser variants of the disorder or broad phenotypes of autism in first-degree relatives. The mild variant of the broad phenotype included abnormality in only one area – communication or social interaction or stereotyped behaviour. A severe variant included abnormalities in at least two of these three areas.
Wing (1981) used the term’ Autistic Continuum’ and later (Wing 1996) the Autistic Spectrum allowing for a broader definition of autism encountered in the disorder. The use of these terms (continuum and spectrum) emphasised the wide range of social difficulties. The solitary withdrawn child with little emotional expression is at one end. The passive child who does not resist social interaction lies in the middle of the continuum. At the other extreme end of the continuum is the child who interacts actively but in an odd way without relating to the needs or concerns of the persons approached.
The degree of social dysfunction is further complicated by developmental changes within the child. From a withdrawn and isolated toddler, the individual may end up as an ‘ active but odd’ teenager. However, the underlying problem still exists and impacts various aspects of social and learning skills. (Jordan, R. Unit 2, Social & Emotional Needs, 2000).
Different levels of cognitive, communication and language abilities further complicate the varying clinical pictures of ASD. The verbal, bright but socially inept child in mainstream school contrasts markedly to a non-verbal, withdrawn and isolated child who is in a special centre. Although an association between cognitive ability and severity of autism has been indicated (Shah & Wing, 1983), social impairment has been seen to occur in ASD individuals with normal or superior intellectual functioning. It is from the highly able autistic individuals that we have learnt more about the disorder (Grandin T, Williams, D.) Atypical Autism, Pervasive Developmental Disorder, PDD NOS, Aspergers Syndrome, Semantic Pragmatic Disorders are the various labels given to the differing pictures of autism spectrum disorders (Wing 1997).
Epidemiology and Prevalence:
Recent studies have yielded prevalence estimates that are much higher than those reported earlier (Bryson 1997, Wing 1993). From 4 to 5 per 10,000 persons (Lotter 1966), the prevalence seems to have increased to 1 per 1000 (Bryson, Clark and Smith 1988, Sugiyama &Abe 1989) to 1 in 131 in Granite bay California, and 1 in 138 in Kingston UK and 1 in 151 in Brick Township New Jersey USA (Shattock et al 2002). Broader criteria used for inclusion, an increasing awareness of its expression in both cognitively impaired and cognitively capable individuals and exhaustive screening of geographically defined populations maybe the reasons that have yielded higher prevalence rates (Bryson S.E. 1997). However, there are a number of recent studies, most with small samples, and several reports from school systems that found even higher rates of autism (Shattock et al 2002 )
Higher prevalence rates are seen among the male gender compared to female gender (Lotter 1966, Wing and Gould 1979) and among first-generation immigrants (Gillberg et al 1987, Wing 1980). Wing and Gould (1979) also noted hat 30 percent of the disabled population suffered from autism.
