ASD: Autism Spectrum Disorder

Autism Spectrum Disorder (ASD) includes a range of complex neurodevelopmental disorders characterized by repetitive behaviors and impairments in social development and communication (American Psychological Association, 1994, World Health Organization, 1994, National Institute of Neurological Disorders and Strokes-NIH, 2012).

Currently, the ASD category includes Autism, Asperger Syndrome, Nonverbal Learning Disability, and Pervasive Developmental Disorder Not Otherwise Specified (PDD-NOS).

Experts estimate that 1 out of every 68 children age 8 have an ASD (Centers for Disease Control and Prevention: Autism Spectrum Disorders: Data & Statistics). Although in recent years there has been a dramatic increase in the number of individuals identified as having ASD, the reasons are unclear. Some of this increase may result from better education about the symptoms of ASD or from more accurate diagnoses of ASD. While some researchers are examining genes and environmental factors, other researchers are looking at possible neurological factors that may be involved.

Additional information about the signs and symptoms of ASD can be found at:
Autism Overview (from the National Institute of Child Health and Human Development) 

Individuals with ASD often possess extraordinary gifts in areas such as music, technology or specific subject areas in which they have taken an interest. However, abstract reasoning, sensory integration, understanding social pragmatics and interpreting social cues are typically challenging for these individuals (Filipek et al., 2000).

In general, the average age of diagnosis is around three years old, although a number of the behavioral symptoms of autism are observable by 18 months of age, including: problems with eye contact, not responding to one’s name, joint attention problems, underdeveloped skills in pretend play and imitation and problems with nonverbal communication and language (Lord, 1995; Stone, 1999; Charman, 1997).

Understanding ASD

  • ASD is diagnosed according to guidelines listed in the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5). If initial screening instruments indicate the possibility of an ASD, a more comprehensive evaluation consisting of neurological assessments and in-depth cognitive and language testing is usually conducted by a multidisciplinary team.
  • The hallmark feature of ASD is impaired social interactions. The main signs and symptoms of autism involve difficulties in the following areas:
    • Communication: both verbal (spoken) and nonverbal (unspoken, such as pointing, eye contact, and smiling)
    • Social: such as sharing emotions, understanding how others think and feel, and holding a conversation
    • Routines or repetitive behaviors (also called stereotyped behaviors): such as repeating words or actions, obsessively following routines or schedules, and working in repetitive ways
  • No two individuals with ASD are exactly alike. The term “spectrum” refers to the wide range of symptoms, skills and levels of impairment that individuals with ASD can have. The severity of ASD symptoms varies tremendously from person to person. Some individuals are mildly impaired by their symptoms while others are severely disabled.
  • Males, siblings of those with ASD, and individuals with other developmental disorders, such as Fragile X, are at higher-than-normal risk for ASD. Males are five times more likely to have an ASD than females (Centers for Disease Control and Prevention: Autism Spectrum Disorders: Data & Statistics). Knowledge of ASD is always growing as research examines more and different sides of the disorder; however, studying this kind of co-occurrence helps researchers who are trying to pinpoint the genetic and environmental factors involved in ASD. 
  • Individuals with ASD have many cognitive strengths, and about 46 percent of this population have average to above average intellectual abilities (Centers for Disease Control and Prevention: Autism Spectrum Disorders: Data & Statistics).
  • ASD is a lifelong condition. There is no cure for autism, nor is there one single treatment for ASD. There are ways to help minimize the symptoms of ASD and to maximize learning: visit Landmark College Institute for Research and Training (LCIRT) for more information.

Resources on ASD


ASD Definition

  • CDC Centers of Disease Control and Prevention. (2014). Autism Spectrum Disorder.
  • American Psychiatric Association. (2013). Diagnostic and statistical manual of mental disorders (5th ed.): DSM-5. Washington, DC: Author.

Understanding ASD Diagnosis

Johnson, C.P. & Myers, S.M. (2007). Identification and evaluation of children with autism spectrum disorders. Pediatrics, 20 (5), 1183-1215. Copyright: American Academy of Pediatrics.

Semrud-Clikeman, M., Walkowiak, J., Wilkinson, A. & Butcher, B. (2010). Executive functioning in children with Asperger syndrome, ADHD-combined type, ADHD predominantly inattentive type, and controls. Journal of Autism and Developmental Disorders, 40, 1017-1027.

For scholarly publications, grants, and research on LD, ADHD and ASD, visit
Landmark College Institute for Research & Training (LCIRT)

For books and general information on LD, ADHD and ASD, visit
Landmark College Library LD, ADHD & ASD Research Collection

Learn more about the progressive and innovative services for students with ASD at Landmark College.

For additional information:

Landmark College Institute
for Research and Training
19 River Road South
Putney, VT 05346