Column jspn_200 206..

209

Defining Autism Spectrum Disorders

Supapak Phetrasuwan, Margaret Shandor Miles, and Gary B. Mesibov

Column Editor: Cordelia Robinson

A utism Spectrum Disorders (ASD) are a group of five

closely-related neurobiological disorders, including Autistic
The most recent edition of the DSM-IV-TR (APA, 2000)
includes five related disorders on the autism spectrum under
Disorder, Asperger’s Disorder, Pervasive Developmental the Pervasive Developmental Disorder (PDD) umbrella: (i)
Disorder Not Otherwise Specified (PDD-NOS), Childhood Autistic Disorder, (ii) Asperger’s Disorder, (iii) Pervasive
Disintegrative Disorder, and Rett’s Disorder. ASD is among Developmental Disorder Not Otherwise Specified (PDD-
the most disabling and mystifying of all childhood develop- NOS), sometimes called atypical autistic disorder, (iv) Child-
mental disorders because these individuals have an atypical hood Disintegrative Disorder, and (v) Rett’s Disorder (APA,
pattern of development that affects multiple areas of func- 2000). More recently, many prefer the umbrella term ASD
tioning (Hilt & Metz, 2008; World Health Organization, and use that term instead of PDD because it more clearly
2006). presents these conditions as a spectrum of related disorders
The definitions and boundaries of ASD have evolved over rather than a specific set of diagnostic labels (Strock, 2007;
decades, leaving a confusing array of terminology for clini- Hilt & Metz, 2008). The boundaries between these disorders
cians. Autistic Disorder is generally referred to as autism and, are unclear, although they share a triad of neurological
less frequently, as childhood autism, or infantile autism. impairments including social and communication difficulties
Rett’s Disorder sometimes appears as Rett Disorder or syn- along with narrow, perseverative, and repetitive behaviors.
drome. Asperger’s Disorder is also referred to as a syndrome The major diagnosis under the ASD umbrella term is
or referred to as high functioning autism. PDD-NOS may Autistic Disorder. There are three key areas of developmen-
simply be labeled as Pervasive Developmental Disorders tal problems in children diagnosed with Autistic Disorder: (i)
(PDD). The umbrella term, ASD, is sometimes labeled Autis- impairment in social interaction (such as impaired nonverbal
tic Spectrum Disorder (Freitag, 2007; Strock, 2007). behaviors, poor peer relationships, difficulty sharing enjoy-
The purpose of this paper is to summarize the historical ment and interests with others) and a lack of social or emo-
evolution of the definitions for ASD and present the most tional reciprocity; (ii) severe delays or lack of language
current classifications, along with a brief overview of some of communication skills, impaired ability to initiate or sustain
the key behavioral and developmental problems related to conversation with others, repetitive use of language, and lack
each disorder. The role of pediatric nurses in a variety of of appropriate social imitative play; and (iii) repetitive and
settings in surveillance and early assessment are identified. stereotyped patterns of behavior, interest, and activities
including preoccupation and intense focus in restricted areas
Definitions of interest, inflexible adherence to routines or rituals, stereo-
typed and repetitive motor mannerisms, and persistent pre-
Two Austrian psychiatrists described two subtypes of occupation with parts of objects (APA, 2000; Filipek et al.,
ASD in the 1940s. Kanner in 1943 reported an unusual con- 2000; Hilt & Metz, 2008; Strock, 2007; Volkmar, Klin, Paul, &
dition characterized by social aloofness, impaired social Cohen, 2005).
interactions, disturbances in language development, and The differences between Autistic Disorder and the other
rigidity and problems with change, which he labeled “classic diagnoses along the autism spectrum are not well delineated
autism or Kannerian autism.” In the ensuing years, many (APA, 2000; Filipek et al., 2000; Hilt & Metz, 2008; Kuschner,
terms were used to stand for this disorder, such as infantile Bennetto, & Yost, 2007; Strock, 2007; Volkmar et al., 2005).
autism, pervasive developmental disorder-residual type, Individuals with Asperger’s Disorder show more subtle
childhood schizophrenia, and autism psychoses among impairments in language, no delay in early language devel-
others (Filipek et al., 1999). The first official clinical definition opment, and have IQs no lower than 70. PDD-NOS is used
for autism in the United States was published in 1980 by the when clinically significant autistic symptoms are present but
American Psychiatric Association (APA) in the Diagnostic and there are not enough of them for a diagnosis of autistic dis-
Statistical Manual of Mental Disorders (DSM). Asperger in order. Children with Childhood Disintegrative Disorder
1944 described a syndrome from four children in his care differ from other ASD diagnoses in that they show a distinc-
who had serious difficulty in social interactions. He labeled tive pattern of developmental regression following a normal
the syndrome “autistic psychopathy” and defined it as course of development for the first 2 years of life or some-
marked social isolation. times longer. They experience loss of previously acquired

206 © (2009), The Authors

Journal Compilation © (2009), Wiley Periodicals, Inc.
Table 1. Autism Spectrum Disorders Diagnoses, Developmental and Behavioral Manifestations, and Age of Symptom
Appearance

Age when symptoms

Diagnostic category Developmental and behavioral manifestations manifested

Autistic Disorder • Impaired social interaction Infancy to early

• Impaired language and communication preschool
• Restricted repetitive and stereotyped patterns of behavior, interests, and
activities
Asperger’s Disorder • Less severe autistic behaviors Infancy to early
• Less impairment in cognitive function (IQ not less than 70) preschool and
• No significant delay in language sometimes later
• Language remains fixed on particular topics
Pervasive • Social impairment most noted symptom, but fewer than needed for Infancy to early
Developmental autistic disorder diagnosis preschool
Disorder Not • Either communication difficulties or stereotyped behaviors or interests
Otherwise Specified
(PDD-NOS)
Childhood • Loss of previously acquired skills after 2 years of age After 2 years
Disintegrative • Abnormal communication
Disorder • Abnormal social interaction
• Repetitive, stereotyped behavior
Rett’s Disorder • Abnormal sleep in infancy Between 7 and 18
• Rapid deterioration of behavior and mental status after 7–18 months of months of age
age (except for
• Deceleration of normal head growth abnormal sleep)
• Loss of hand skills
• Loss of social skills
• Poorly coordinated gait and trunk movements
• Severe language impairment
• Psychomotor retardation

skills in language, social skills, bowel or bladder control or wide population studies suggested that prevalence of ASD
play, and motor skills, as well as the three autistic symptoms was 0.4 or 0.5 children per 1,000 (Lotter, 1966). More recently,
of abnormal communication, social interaction, and repeti- the Centers for Disease Control and Prevention (CDC) indi-
tive, stereotyped behavior. Rett’s Disorder appears mainly in cated that the 2000 and 2002 prevalence was 6.6 to 6.7 per
girls and is a degenerative disorder. After experiencing 1,000 children (Rice, 2007). Thus, approximately 1 in 150 chil-
apparently normal early development with the exception of dren in the United States have ASD, and the numbers are
sleep problems, affected children experience a progressive increasing internationally as well (Belfer, 2008; World Health
regression in development between 7 and 18 months of age. Organization, 2006). In addition, many people with ASD may
This pattern includes declines in cognition, behavior, social still remain unidentified (Filipek et al., 1999; Fisher, 2005;
skills, and motor development including slowing of normal Wing & Potter, 2002). It is important to note that ASD crosses
head growth, deterioration of hand skills, and social engage- all racial, ethnic, and social boundaries, and it occurs four
ment, poor coordination, and, over time, severe impairment times more often in boys than in girls (Belfer, 2008; Filipek
of language and psychomotor retardation (APA, 2000; Hilt & et al., 2000; Sugiyama & Abe, 1989).
Metz, 2008). Table 1 provides a brief summary of the devel-
opmental and behavioral manifestations of each diagnosis. Summary
The broadening of the diagnostic criteria and the
expanded clinical recognition and diagnosis of conditions on A consensus has emerged that autistic disorder and
the autism spectrum has likely influenced the reports of related disorders are now thought of as a spectrum disorder,
increased incidence worldwide (Bryson, 1996; Fombonne, labeled as ASD. While all children with diagnoses under the
1996; Gillberg, Steffenburg, & Schaumann, 1991; Rice, 2007; ASD umbrella demonstrate the same core deficits, these
Rutter, 2005; Sugiyama & Abe, 1989). Prior to 1985, world- symptoms are manifested in a wide variety of ways, ranging

JSPN Vol. 14, No. 3, July 2009 207

Column

from those who are very severely affected with many char- Observation Schedule-Generic (Lord et al., 2000). These tools
acteristics to those who show only mild effects with fewer are complex, time consuming to administer, and require
characteristics or who remain nearly normal (Fisher, 2005). extensive training.
For example, the level of intellectual function can range from Nurses have an important role in helping parents of
profound mental retardation through the superior range on newly diagnosed children understand the particular disor-
conventional IQ tests, although about 40% of children have der as well as the full spectrum of ASD. Confusing labels
some level of retardation. This concept of ASD and the dis- for the same disorder may upset parents who need help in
abilities under this umbrella as a spectrum disorder has clarifying the various terms used to discuss the same dis-
been useful in facilitating the diagnosis of younger and order. Parents also need help in understanding their chil-
younger children and in providing appropriate educational dren’s atypical behavior and in finding appropriate
approaches and parental interventions geared to the indi- resources and interventions that can maximize their chil-
vidual behavioral and developmental manifestations seen in dren’s potential (Inglese, 2009; Schuntermann, 2002;
the individual child (Rutter, 2005; Wing & Potter, 2002). Tomanik, 2004). These children and their parents often need
The CDC (2007), in partnership with the American special interventions to help them cope with healthcare
Academy of Pediatrics (AAP) and the Autism Society have encounters, particularly hospitalizations. Parents of children
organized the Learn the Signs, Act Early campaign to assist with ASD experience many challenges and stress in parent-
parents and providers. Developmental charts and videos are ing their children. They need interventions to reduce their
available on the Web site at http://www.cdc.gov/ncbddd/ stress and help them learn how to manage their children’s
autism/screening.htm. Nurses who work with children in a behaviors and other problems (Diggie, McConachie, &
variety of settings have a unique opportunity to meet this Randle, 2003; Tomanik, 2004; Phetrasuwan & Miles, 2009).
mandate. Nurse practitioners and pediatric office nurses, in Two organizations of importance to parents are the Autism
particular, need to place importance on assessing and iden- Society of America (www.autism-society.org) and Autism
tifying behaviors that may indicate symptoms of one of the Speaks (www.autismspeaks.org).
ASD diagnoses (Inglese, 2009). Attention to this issue in the
primary care setting is especially important as symptoms of Supapak Phetrasuwan, RN, PhD
many of the ASD diagnoses appear in infancy and early Instructor
childhood but many children are not diagnosed for months Faculty of Nursing, Srinakharinwirot University
or years after the symptoms have been noted by parents Thailand
(Dawson et al., 2002; Inglese, 2009; Filipek et al., 2000;
Volkmar et al., 2005). Delays result in loss of opportunities Margaret Shandor Miles, RN, PhD, FAAN
for early developmental and parenting interventions that can Professor Emeritus
maximize the well-being of the child.
School of Nursing, The University of North Carolina
Assessing children for symptoms of ASD is complex as
there are no definitive biologic tests (CDC, 2007). The CDC
Chapel Hill, North Carolina, USA
recommends developmental screening and surveillance of
all children during well-child visits at 9 months, 18 months,
Gary B. Mesibov, PhD
and 24 or 30 months of age. Likewise, the AAP has a detailed Professor and Director of TEACCH
algorithm regarding assessment and referral of children sus- Department of Psychiatry, School of Medicine, The
pected of having ASD (2006). It is strongly recommended that University of North Carolina
every pediatric and public health practice have this algo- Chapel Hill, North Carolina, USA
rithm posted in their practice. There are a growing number of
tools targeted to assess and diagnose ASD more specifically. Cordelia Robinson
However, not all of them have sufficient psychometric Column Editor
testing to show evidence of accuracy and reliability in pre-
dicting or diagnosing ASD. The Modified Checklist for Author contact: mmiles@email.unc.edu, with a copy to the
Autism in Toddlers (M-CHAT; Robins, Fein, Barton, & Green, Editor: roxie.foster@UCDenver.edu
2001) is a 23-item parent-report checklist designed to screen
children ages 16–30 months old and may be more appropri- Search terms: Autism Spectrum Disorder, definitions
ate for primary care screening. For a complete listing of tools,
see the AAP article (2006) and the CDC Web site. References
At the present time, the “gold standard” for diagnosis
of ASD is the Autism Diagnosis Interview-Revised (Lord, American Academy of Pediatrics. (2006). Identifying infants and
Rutter, & LeCouteur, 1994) and the Autism Diagnostic young children with developmental disorders in the medical

208 JSPN Vol. 14, No. 3, July 2009

 home: An algorithm for developmental surveillance and screen- Kuschner, E. S., Bennetto, L., & Yost, K. (2007). Patterns of nonverbal
ing. Pediatrics, 118, 405–420. cognitive functioning in young children with Autism Spectrum
American Psychiatric Association. (1980). Diagnosis and statistical Disorders. Journal of Autism and Developmental Disorders, 37, 795–
manual of mental disorders. Washington, DC: Author. 807.
American Psychiatric Association. (2000). Diagnosis and statistical Lord, C., Rutter, M., & LeCouteur, A. (1994). Autism Diagnostic
manual of mental disorders (4th ed., Text Revision). Washington, Interview—Revised: A revised version of a diagnostic interview
DC: Author. for caregivers of individuals with possible pervasive develop-
Asperger, H. (1944, 1991). “Autistic psychopathy” in childhood. In mental disorders. Journal of Autism and Developmental Disorders,
U. Frith (Ed.), Autism and Asperger syndrome (pp. 37–92). Cam- 24, 659–685.
bridge, UK: Cambridge University Press. Lord, C., Risi, S., Lambrecht, L., Cook, E. H., Leventhal, B. L., DiLa-
Belfer, M. L. (2008). Child and adolescent mental disorders: The vore, P. C., et al. (2000). The Autism Diagnostic Observation
magnitude of the problem across the globe. Journal of Child Psy- Schedule—Generic: A standard measure of social and communi-
chology and Psychiatry, 49, 226–236. cation deficits associated with the spectrum of autism. Journal of
Bryson, S. E. (1996). Brief report—Epidemiology of autism. Journal of Autism and Developmental Disorders, 30, 205–223.
Autism and Developmental Disorders, 26, 165–167. Lotter, V. (1966). Epidemiology of autistic conditions in young chil-
Centers for Disease Control and Prevention. (2007). Autism Informa- dren. I. Prevalence. Social Psychiatry, 1, 124–137.
tion Center. Retrieved February 7, 2009, from www.cdc.gov/ Phetrasuwan, S., & Miles, M. S. (2009). Parenting stress in mothers of
NCBDDD/autism/screening.htm children with Autism Spectrum Disorder. Journal for Specialists in
Dawson, G., Munson, J., Estes, A., Osterling, J., McPartland, J., Toth, Pediatric Nursing, 14(3).
K., et al. (2002). Neurocognitive function and joint attention Rice, C. (2007). Prevalence of autism spectrum disorders—Autism
ability in young children with autism spectrum disorder versus and Developmental Disabilities Monitoring Network, six sites,
developmental delay. Child Development, 73, 345–358. United States, 2000. CDC Mortality and Morbidity Weekly Report, 56
Diggie, T., McConachie, H. R., & Randle, V. R. L. (2003). (SS01), 1–11.
Parent-mediated early intervention for young children with Robins, D. L., Fein, D., Barton, M. L., & Green, J. A. (2001). The
autism spectrum disorder. The Cochrane Database of Systematic Modified Checklist for Autism in Toddlers: An initial study inves-
Reviews, Issue 1. Art. No.: CD003496. D01: 10.1002/14651858. tigating the early detection of autism and pervasive developmen-
CD003496. tal disorders. Journal of Autism and Developmental Disorders, 31,
Filipek, P. A., Accardo, P. J., Ashwal, S., Baranek, G. T., Cook, E. H., 131–144.
Dawson, G., et al. (2000). Practice parameter: Screening and diag- Rutter, M. (2005). Incidence of autism spectrum disorders: Changes
nosis of autism: Report of the Quality Standards Subcommittee of over time and their meaning. Acta Paediatrica, 94, 2–15.
the American Academy of Neurology and the Child Neurology Schuntermann, P. (2002). Pervasive developmental disorder and
Society. Neurology, 55, 468–479. parental adaptation: Previewing and reviewing atypical develop-
Filipek, P. A., Accardo, P.J., Baranek, G. T., Cook, E. H., Dawson, G. I., ment with parents in child psychiatric consultation. Harvard
& Gordon, B., et al. (1999). The screening and diagnosis of autistic Review of Psychiatry, 10, 16–27.
spectrum disorders. Journal of Autism and Developmental Disorders, Strock, M. (2007). Autism spectrum disorders (Pervasive development
29, 439–484. disorders) with addendum. Retrieved October 8, 2008, from
Fisher, F. (2005). Incidence of autism. Archives of Pediatric and Adoles- http://www.nimh.nih.gov/health/publications/autism/
cent Medicine, 159, 691–702. nimhautismspectrum.pdf
Fombonne, E. (1996). Is the prevalence of autism increasing? Journal Sugiyama, T., & Abe, T. (1989). The prevalence of autism in Nagoya,
of Autism and Developmental Disorders, 26, 673–676. Japan: A total population study. Journal of Autism and Developmen-
Freitag, C. M. (2007). The genetics of autistic disorders and its clinical tal Disorders, 19, 87–96.
relevance: A review of the literature. Molecular Psychiatry, 12(1), Tomanik, S. (2004). The relationship between behavior exhibited by
2–22. children with autism and maternal stress. Journal of Intellectual
Gillberg, C., Steffenburg, S., & Schaumann, H. (1991). Is autism more and Developmental Disabilities, 29, 16–27.
common now than ten years ago? British Journal of Psychiatry, 158, Volkmar, F., Klin, A., Paul, R., & Cohen, J. D. (2005). Handbook of
403–409. autism (3rd ed.). New York: Wiley.
Hilt, R. J., & Metz, W. P. (2008). Autistic spectrum disorders. eMedi- Wing, L., & Potter, D. (2002). The epidemiology of autism spectrum
cine. Retrieved February 7, 2009, from www.emedicine.com/ disorders: Is the prevalence rising? Mental Retardation and Devel-
med/TOPIC3202.HTM opmental Disabilities Research Review, 8, 151–161.
Inglese, M. D. (2009). Caring for children with autism spectrum World Health Organization. (2006). Pervasive developmental disor-
disorder, Part II: Screening, diagnosis, and management. Journal ders. International Statistical Classification of Diseases and Related
of Pediatric Nursing, 24, 49–59. Health Problems (10th ed.; ICD 10). Retrieved October 8, 2008, from
Kanner, L. (1943). Autistic disturbances of affective contact. Nervous http://www.who.int/classifications/apps/icd/icd10online/?gf
Child, 2, 217–250. 80.htm+f840

JSPN Vol. 14, No. 3, July 2009 209