Neurodevelopmental Disorders


Learn more about the symptoms of Autism Spectrum Disorder, Intellectual Disabilities, and Communication Disorders.

Autism Spectrum Disorder 

  • Persistent deficits in social communication and social interaction as evidenced by:
    • Deficits in social-emotional reciprocity.  Some examples include abnormal social approach and failure of normal back-and-forth conversation; reduced sharing of interests, emotions, or affect; and failure to initiate or respond to social interactions.
    • Deficits in nonverbal communication used for social interaction. Some examples include abnormal eye contact and body language or deficits in understanding and use of gestures; to a total lack of facial expressions and nonverbal communication.
    • Deficits in developing, maintaining, and understanding relationships.  Some examples include difficulties adjusting behavior to fit different social situations; difficulties sharing imaginative play or in making friends; and lack of interest in peers.
  • Restricted, repetitive patterns of behavior, interests, or activities, as evidenced by at least two of the following:
    • Stereotyped or repetitive motor movements, use of objects or speech (such as simple motor stereotypies, flipping objects or lining up toys, repeating other’s words, and inappropriate word usage).
    • Inflexible adherence to routines, insistence on sameness, or ritualized patterns of verbal or nonverbal behavior (such as extreme distress at small changes, difficulties with transitions, greeting rituals, rigid thinking patterns, and the need to take the same route or eat the same food every day).
    • Highly restricted, fixated interests that are abnormal in intensity or focus (strong attachment to or preoccupation with unusual objects, excessively circumscribed or perseverative interests).
    • Hyperreactivity or hyporeactivity to sensory input or unusual interest in sensory aspects of the environment (such as apparent indifference to pain/temperature, adverse response to specific sounds or textures, excessive smelling or touching of objects, and visual fascination with lights or movement).
  • Symptoms must be present in the early developmental period.
  • Symptoms cause clinically significant impairment in social, work, or other important areas of functioning.
  • These disturbances are not better explained by intellectual disability or global developmental delay.

Intellectual Disabilities

Intellectual Disability (Intellectual Developmental Disorder) 

Intellectual Disability is a disorder with onset during the developmental period that includes intellectual and adaptive functioning deficits in social, conceptual and practical domains.  The following three criteria must be met:

  • Deficits in intellectual functions, such as problem solving, reasoning, planning, abstract thinking, academic learning, judgement, and learning from experience, confirmed by both clinical assessment and standardized intelligence testing.
  • Deficits in adaptive functioning that result in failure to meet developmental and sociocultural standards for social responsibility and personal independence.  Without continued support, the adaptive deficits limit functioning in one or more activities of daily life, such as social participation, communication and independent living.
  • The intellectual and adaptive deficits occur during the developmental period.

*The degree of intellectual disability is specified by mild, moderate, severe or profound.

Global Developmental Delay

This diagnosis is for children under that age of five years that fail to meet expected developmental milestones in several areas of intellectual functioning and are unable to undergo systematic assessments of intellectual functioning, including children who are too young to participate in standardized testing.  This category requires reassessment after a period of time.

Unspecified Intellectual Disability

This diagnosis is for individuals over the age of five years when assessment of the degree of intellectual disability by means of locally available procedures is difficult or impossible because of sensory or physical impairments, such as blindness or pre-lingual deafness; locomotor disability; or the presence of severe problem behaviors or co-occurring mental disorder.  This category requires reassessment after a period of time and should only be used in exceptional circumstances.

Communication Disorders

Language Disorder 

  • Persistent difficulties in the learning and use of language across modalities (such as spoken, written, or sign language) due to deficits in comprehension or production that include:
    • Reduced word knowledge and use (vocabulary).
    • Limited sentence structure (ability to put words and word endings together to form sentences based on the rules of grammar).
    • Impairments in the ability to use vocabulary and connect sentences to explain or describe a topic or series of events or have a conversation.
  • Language abilities are substantially and quantifiably below those expected for age, resulting in functional limitations in effective communication, academic achievement, social participation, and/or occupational performance.
  • The onset of symptoms is in the early developmental period.
  • The difficulties are not attributable to hearing or other sensory impairment, motor dysfunction, or another medical or neurological condition, or intellectual disability or global developmental delay.

Speech Sound Disorder 

  • Persistent difficulty with speech sound production that interferes with speech intelligibility or prevents verbal communication.
  • The disturbance causes limitations in communication that interfere with academic achievement, social participation, and/or work performance.
  • The onset of symptoms is in the early developmental period.
  • The difficulties are not attributable to congenital or acquired conditions, such as cerebral palsy, cleft palate, hearing loss or deafness, traumatic brain injury, or other medical or neurological conditions.

Childhood-Onset Fluency Disorder (Stuttering) 

  • Disturbances in the normal fluency and time patterning of speech that are inappropriate for the individual’s age and language skills, and are characterized by one or more of the following:
    • Sound and syllable repetitions.
    • Sound prolongations of consonants and vowels.
    • Broken words.
    • Audible or silent pauses in speech.
    • Circumlocutions (word substitutions to avoid difficult words).
    • Words produced with an excess of physical tension.
    • Monosyllabic whole-word repetitions (such as “I-I-I-I want that”).
  • Disturbance causes anxiety about speaking or limitations in effective communication, social participation, or academic or work performance.
  • The onset of symptoms is in the early developmental period.
  • The disturbance is not attributable to a speech, motor or sensory deficit; dysfluency associated with a neurological condition; or other medical or mental condition.

Social (Pragmatic) Communication Disorder 

  • Persistent difficulties in the social use of verbal and nonverbal communication as manifested by all of the following:
    • Deficits in using communication for social purposes, such as greeting and sharing information.
    • Impairment of the ability to change communication to match context or the needs of the listener, such as talking differently to a child than to an adult, and avoiding use of overly formal language.
    • Difficulties following rules for conversations and storytelling, such as taking turns in conversation and knowing how to use verbal and nonverbal signals.
    • Difficulties understanding what is not explicitly stated and non-literal meanings of language (such as humor, metaphors, idioms).
  • The deficits result in functional limitations in effective communication, social relationships, social participation, academic achievement, or work performance.
  • The onset of symptoms are not attributable to another medical or neurological conditions, intellectual disability, global developmental delay or other mental disorder.

The above criteria are adapted from the Diagnostic and Statistical Manual of Mental Disorders (DSM-5).