How to Diagnose Autism?

The Childhood Autism Rating Scale (CARS) is a behavior rating scale intended to help identify children 2 years and older children with Autism, specifically, distinguishing them from developmentally handicapped children who are not Autistic. In addition, it distinguishes between mid-to-moderate and severe Autism. Since its original publication, the CARS has become one of the most widely used and empirically validated autism assessment techniques. It has proven effective in discriminating between children with autism and those with severe cognitive deficits, and in distinguishing mild-to-moderate from severe autism.

The Childhood Autism Rating Scale (CARS) is a 15 item behavioral rating scale developed to identify children with autism and to categorize these behaviors from mild to moderate to severe. Each item covers a particular characteristic, ability of behavior. The total CARS score may range from a low of 15 (obtained when the child’s behavior is rated as falling within normal limits on all 15 scales) to a high of 60 (obtained when the child’s behavior is rated as severely abnormal on all 15 scales). The score represents placement on a continuum: the lower the score, the fewer autistic behaviors the child exhibits; the higher the score, the more autistic behaviors the child exhibits.

The scores are given as follows:

Relating to People                                                               XX

Emotional Response                                                           XX

Imitation                                                                               XX

Body Use                                                                              XX

Object Use                                                                            XX

Adaptation to Change                                                        XX

Listening Response                                                             XX

Taste, Smell, Touch                                                            XX

Visual Response                                                                  XX

Fear or Nervous                                                                   XX

Verbal Communication                                                     XX

Activity Level                                                                       XX

Nonverbal Communication                                              XX

Level & Consistency of Intellectual Response              XX

General Impression                                                             XX


Total Score                                                                          XX

CARS evaluation is done by your primary healthcare provider by rating the child’s behaviors from 1 to 4. 1 being normal for your child’s age, 2 for mildly abnormal, 3 for moderately abnormal and 4 as severely abnormal. Scores range form 15 to 60 with 30 being the cutoff rate for a diagnosis of mild autism. Scores 30-37 indicate mild to moderate autism, while scores between 38 and 60 are characterized as severe autism.

Childhood Autism Rating Scale, Second Edition (CARS-2)

Covering the entire Autism Spectrum including Asperger’s Syndrome, the Childhood Autism Rating Scale, Second Edition (CARS-2) helps you to identify children with autism and determine symptom severity through quantifiable ratings based on direct observation.

Widely used and empirically validated, the CARS-2 has proven to be especially effective in:

  • Discriminating between children with autism and those with severe cognitive deficits
  • Distinguishing mild-to-moderate from severe autism

The CARS 2 addresses the following functional areas, among others:

  • Relating to People
  • Body Use
  • Visual Response
  • Listening Response
  • Taste, Smell, and Touch Response and Use
  • Verbal Communication
  • Nonverbal Communication
  • Level and Consistency of Intellectual Response

The CARS2 includes three forms:
1) Standard Version Rating Booklet (ST)
Equivalent to the original CARS; for use with individuals younger than 6 years of age and those with communication difficulties or below-average estimated IQs

2) High-Functioning Version Rating Booklet (HF)
An alternative for assessing verbally fluent individuals, 6 years of age and older, with IQ scores above 80

3) Questionnaire for Parents or Caregivers (QPC)
An unscored scale that gathers information for use in making ST and HF ratings

1 & 2) The Standard and High-Functioning Forms
The Standard and High Functioning Forms each include 15 items addressing the following functional areas:

  • Relating to People
  • Imitation (ST); Social-Emotional Understanding (HF)
  • Emotional Response (ST); Emotional Expression and Regulation of Emotions (HF)
  • Body Use
  • Object Use (ST); Object Use in Play (HF)
  • Adaptation to Change (ST); Adaptation to Change/Restricted Interests (HF)
  • Visual Response
  • Listening Response
  • Taste, Smell, and Touch Response and Use
  • Fear or Nervousness (ST); Fear or Anxiety (HF)
  • Verbal Communication
  • Nonverbal Communication
  • Activity Level (ST); Thinking/Cognitive Integration Skills (HF)
  • Level and Consistency of Intellectual Response
  • General Impressions

Items on the Standard Form duplicate those on the original CARS, while items on the HF form have been modified to reflect current research on the characteristics of people with high functioning autism or Asperger’s Syndrome.

The clinician rates the individual on each item, using a 4-point response scale. Ratings are based not only on frequency of the behavior in question, but also on its intensity, peculiarity, and duration. While this more nuanced approach gives you greater flexibility in integrating diagnostic information, it still yields quantitative results.