105 Pervasive Developmental Disorder Not Otherwise Specified or PDD-NOS (299.80)

Children diagnosed with PDD-NOS fall into at least one of two categories, if not both:

  • They do not meet the criteria of symptoms utilized by clinicians to diagnose any of the four previously mentioned types of PDD
  • They do not have the degree of impairments outlined in the four types of PDD (Tsai, 1998).

This category should be utilized when there is a severe and pervasive impairment in the development of social interaction or verbal and nonverbal communication skills, or when stereotyped behavior, interests, and activities are present, but the criteria are not met for a specific Pervasive Developmental Disorder, Schizophrenia, Schizotypical Personality Disorder, or Avoidant Personality Disorder” (Tsai, 1998).

  • For example, this category includes “atypical autism”– presentations that do not meet the criteria for Autistic Disorder because of late age of onset, atypical symptomatology, or sub-threshold symptomatology, or all of these.
  • PDDNOS is the result of a neurological abnormality; however there is no explanation for its cause(s) (Tsai, 1998).
    • The components used to define this disorder could be the culprit of the failed causal relationships, because PDDNOS includes behavioral symptoms rather than genetic testing.

Children generally reach age 3-4 years old before they portray enough symptoms to cause a parent or caregiver to worry about a diagnosis (Tsai, 1998).

Symptoms for PDDNOS lie on a continuum and vary per child in the degree and intensity of impairments:

  • Social behaviors (Tsai, 1998)
    • Infants may avoid eye contact and exhibit little, if any interest, in human voices.
    • Infants do not usually raise their arms to indicate wanting to be picked up, as normal children do.
    • Young children do not develop typical attachment behaviors and do not exhibit separation or stranger anxiety.
    • Young children lack interest in playing with other children, to the point of actively avoiding others.
    • Middle aged children may show greater attachments towards family members, friends, and peers; however, they still have social impairments.
    • These children lack correct responses towards others’ interests and emotions and may lack the comprehension of humor.
  • Nonverbal communication (Tsai, 1998)
    • Even if children exhibit the normal pulling of adults’ hands toward a desired object, they may do so without exhibiting the proper facial expressions.
    • Children with PDDNOS do not seem to participate in imaginative games and are less likely to imitate their parents’ activities.
      • Some children to participate in imaginative play; however, they tend to exhibit repetitive behaviors.
    • Individuals in middle to late childhood tend not to utilize gerstures.
    • Children with PDDNOS do know how to exhibit emotion.
      • The emotions exhibited are extremes. They do not ordinarily portray subtle facial expressions.
  • Speech (Tsai, 1998).
    • Infants tend not to babble. If they do, the babbling halts within the first year.
    • Echolalia may be the only type of speech acquired.
      • Even if echolalic speech is accurately produced, comprehension may be limited.
      • Echolalia serves several functions
        • self stimulation
        • the step between being nonverbal and verbal
        • sufficient communication
    • Some develop efficient phrase usage; however, is accompanied by pronoun reversal.
    • Impairments in speech production are evident, to include monotonous, flat, robotic sounds that lack pitch change, emphasis, or emotion.
    • Odd speech characteristcs exhibited by children with PDDNOS include singsong speech, question-like statements, odd breathing rhythms, etc.
    • Abnormal grammar in verbal children results in:
      • distorted phrases
      • muddled sounding synonyms or similar sounding words
      • labeling objects by their use
      • inventing new words
      • incorrect usage of prepositions, conjunctions, and pronouns.
    • Speech lacks imagination, abstraction, or subtle emotion
    • Children have difficulties discussing things outside of immediate contexts and ordinary “to-and-fro” conversations.
  • Behavioral Patterns (Tsai, 1998)
    • Children with PDDNOS are resistant to change.
      • They exhibit frustration when their line of toys are disrupted
      • New activities are resisted
    • They exhibit ritualistic/compulsive behaviors.
      • Can involve rigid routines, repetitions, or preoccupations
    • Attachments and behaviors are abnormal.
      • Exhibit intense attachments to odd objects
      • Preoccupation with select features of objects
    • Unsual responses to sensory experiences
      • Under or overresponsive to certain stimuli
      • Some avoid tender contact and enjoy rough play
  • Movement (Tsai, 1998)
    • Motor skills can be delayed; however, lie within the normal range.
    • If they are overactive as young children, they tend to be less so in adolescence.
    • The following behaviors may be continuous or sparatic: grimacing, hand flapping, toe walking, jumping, pacing, swaying, head banging, etc.
  • Cognitive Impairments (Tsai, 1998)
    • Children do well on tests involving manipulative and visual skills or immediate memory, while scores are inadequate when asked to implement logic and abstract thought.
    • Development is impaired in regards to imitation, comprehension, inventiveness, applying rules, and utilizing information.
    • Development excells in rote memory and skills in music, math, and reading.
    • Children diagnosed with PDDNOS who also have a low IQ score tend to lack social skills and exhibit inappropriate social responses (i.e. touching or smelling people).

Testing for PDDNOS (Tsai, 1998)

  • Currently no objective biological assessments to confirm diagnosis
    • Diagnosis reflects clinician’s “best guess”
    • To gain an accurate diagnosis requires a thorough assessment by a trained professional
      • child psychiatrist
      • developmental pediatrician
      • pediatric neurologist
      • child psychologist
      • developmental psychologist
      • neuropsychologist

Assessments, conducted by local public school or private practitioner, are implemented to gather information to determine an accurate diagnosis and to provide information to aid in the appropriate intervention for the child and family.

Medical Assessment

  • Thorough birth, development, medical, and family history
  • Full physical and neurological exam
  • Laboratory tests and/or brain scans (at the physician’s

Genetic and Family Studies

  • Indicates the relationship between PDD-NOS and autism exists by noting the possibility of diagnosis of either genetic disorder in siblings of the diagnosed person (Hoffman, 2009).
  • Immediate relatives of an individual with PDD-NOS may be in a group called the “broader autism phenotype.” This group may exhibit features of PDD-NOS but do not portray enabaling features to carry the diagnosis of PDD-NOS (Hoffman, 2009).


  • Child him/herself
  • Parent
  • Teacher
  • Child may behave differently per setting/situation
  • Rate Behavior
  • Direct Behavioral Observations
  • Psychological assessment
    • Utilize standard instruments to evaluate the following areas
      • Cognitive
      • Social
      • Emotional
      • Behavior
      • Adaptive Function

Educational Assessment

  • Formal and informal tests to evaluate:
    • Preacademic skills
    • Academic skills
    • Daily living skills
    • Learning style and problem solving approaches

Communication assessment

  • Formal testing
  • Observation
  • Parental/Caregiver interviews
  • Assess range of communication skills:
    • Personal interest in communication
    • Purpose for communication
    • Content and context
    • Nonverbal communication
    • Comprehension of communication

Occupational assessment

  • Determine nature of sensory function
  • Assess fine and gross motor skills

Evaluation Summary

  • Utilize all information gathered to determine diagnosis

Treatment for PDDNOS (Tsai, 1998)

  • Behavioral Issues
    • Keep environment organized with clear, concise, and consistent rules.
      • Structure and predictability are essential.
      • Problem behaviors could be a form of communication.
    • Remember in positive behavioral support strategies:
      • Programs are individually based
      • Children with PDDNOS have trouble generalizing from one environment to the next
      • Implementing home-community based approaches can maximize results
      • Adapting to classroom environments can be difficult, therefore:
        • Knowledgeable teachers are essential;
        • Structure, consistency, and predictability should be utilized;
        • Information should be presented visually and verbally;
        • Interaction with nondisabled peers is vital for appropriate language, social, and behavioral skills;
        • Communication devices aid in improving communication skills;
        • Reduced class size and appropriate seating arrangements help to eliminate distractions;
        • Curriculum should be modified depending on the child’s strengths and weaknesses;
        • Combining positive behavioral supports with educational interventions provide better results;
        • Continuous and regular communication between teachers, parents, and primary care physicians is a must.
  • Medical Treatment
    • Medical treatment is to ensure good physical and psychological health.
    • Regular checkups to monitor growth, vision, hearing, blood pressure, dental, diet, and hygiene allow for preventative measures.
    • There is not one specified medication for all children with PDDNOS.
      • Levels of medication require experimentation to determine the optimal dosage
      • Medication regimens are individualistic and are a last resort.
      • If medications are prescribed, they should be taken in conjunctions with other therapies and thoroughly monitored.
  • Psychological treatment
    • Counseling is beneficial in assisting adjustment for the family.
    • Psychologists provide ongoing assessment, school consultation, case management, and behavioral training.
    • Family teamwork eases the burden on the primary caregiver.
  • Additional Options
    • Facilitated Communication encourages individuals with communication impairments to express themselves by utilizing a facilitator to assist in spelling words on a keyboard, typewriter, or computer.
    • Auditory Integration Therapy (AIT) sends randomly selected frequencies from a CD player to the child with PDDNOS, resulting in
      • diminished sensitivity to sounds
      • spontaneous speech
      • development of complex language
      • answering questions
      • increased interaction with peers
      • appropriate social behavior
    • Sensory Integration Therapy sets out to improve how a child’s senses process stimulation and work together to respond efficiently.
    • The Lavaas Method is considered an Applied Behavior Analysis and intended for preschool aged children with autism.
      • Behaviors are molded by rewarding desired behaviors and ignoring undesired behaviors in 4-6 hours per day of one on one training between 5-7 days per week.
    • Vitamin therapy adds B6 and magnesium to the child’s diet to help form malfunctioning neurotransmitters.
    • Dietary intervention may be necessary for some children with PDDNOS because of food sensitivities or allergies.
    • Anti-yeast therapy is assumed by some to reduce negative behaviors.
      • Antibiotics provided to toddlers for ear infections can cause “yeast overgrowth,” which may or may not be a coincidence of the existence of higher yeast levels in children diagnosed with autism and PDDNOS.

DSM-5 is proposing that this disorder be subsumed into the existing Autistic Disorder.

The following video gives insight to an everyday outing with a child with Autism.


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