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Learn about Autism > Diagnosis

There are no medical tests for diagnosing autism. An accurate diagnosis must be based on observation of the individual’s communication, behavior, and developmental levels. However, because many of the behaviors associated with autism are shared with other disorders, various medical tests may rule out or identify other possible causes of the symptoms being exhibited.

Diagnostic Criteria (DSM-5, 2013)

In May of 2013, the American Psychiatric Association (APA) released a new version of the Diagnostic and Statistical Manual of Mental Disorders, the DSM-5.  This manual is the standard reference that healthcare providers use to diagnose mental and behavioral conditions.  The DSM-5 includes a new diagnosis for autism spectrum disorder (ASD), which replaces the previous diagnoses (autism, PDD-NOS, Asperger Syndrome, Rett’s Disorder, and Childhood Integrative Disorder).

In addition to the new ASD diagnosis, there are two related diagnoses, Social Communication Disorder (SCD) and Disruptive Mood Dysregulation Disorder (DMDD).  For further information about the new diagnoses of ASD, SCD, or DMDD, visit http://www.dsm5.org.

Importance of Early Identification

Research indicates that early diagnosis is associated with dramatically better outcomes for individuals with autism. The earlier a child is diagnosed, the earlier he can begin benefiting from one of many specialized interventions.

Diagnostic and Screening Tools

  • Autism Diagnostic Interview - Revised (ADI-R; Rutter, LeCouteur, & Lord, 2003)
  • Autism Diagnostic Observation Schedule - Generic (ADOS-G; Lord, Rutter, DiLavore, & Risi, 2001)
  • Childhood Autism Rating Scale (CARS; Schopler, Reichler, & Renner, 1988)
  • Autism Spectrum Quotient (AQ-Adol; Baron-Cohen, Hoekstra, Knickmeyer, & Wheelwright, 2006; AQ-Child; Auyeung, Baron-Cohen, Wheelwright. & Allison, 2008)
  • Early Screening of Autistic Traits (ESAT; Swinkels et al., 2006)
  • Modified Checklist for Autism in Toddlers (MCHAT; Robbins, Fiein, Barton, & Green, 2001)
  • Screening Tool for Autism in Two-Year-Olds (STAT; Stone, Coonrod, & Ousley, 2000)

Red Flags

The Centers for Disease Control and Prevention (CDC) provide early indicators of ASD. For example, an individual with an ASD may:

  • not play ”pretend” games (e.g., pretend to “feed” a doll)
  • not point at objects to show interest (point at an airplane flying over)
  • not look at objects when another person points at them
  • have trouble relating to others or not be interested in other people at all
  • avoid eye contact and want to be alone
  • have trouble understanding other people’s feelings or talking about own feelings
  • prefer not to be held or cuddled or cuddle only when he or she wants to
  • appear to be unaware when other people talk to him but respond to sounds
  • be very interested in people but not know how to talk, play, or relate to them
  • repeat or echo words or phrases, or repeat words or phrases instead of normal language (echolalia)
  • have trouble expressing needs using typical words or motions
  • repeat actions over and over
  • have trouble adapting when a routine changes
  • exhibit unusual reactions to the way things smell, taste, look, feel, or sound
  • lose skills once demonstrated (e.g., stop saying words she had been using)

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Prevalence of ASD

The prevalence of autism spectrum disorder (ASD) is increasing. On March 28, 2014 the CDC released a new report on the prevalence of ASD. The overall prevalence is now one in 68 children (aged 8 years) based upon 2010 data published in 2014. Based upon the current report, the ASD prevalence estimates one in 42 boys and one in 189 girls. Autism knows no racial, ethnic, or social boundries, and family income, lifestyle, and educational levels do not affect the chance of the occurrence of autism.