Autism Spectrum Disorders Chapter 6

Outline: Autism Spectrum Disorder Defining features Associated characteristics Prevalence & Course Causes Treatment

Defining Features of ASD Difficulties in the following areas, with onset in early life (< age 3) Social interaction & communication Restricted, repetitive patterns of behavior, interests, or activities Autism Spectrum Disorder Neurodevelopmental disorder Differences in those with ASD contributing to the “spectrum” Level of intellectual ability From profound disability to above-average intelligence Severity of language problems Some with ASD are mute; others are able to speak well Behavior changes with age Some make little progress; others develop speech, become more outgoing Those who make progress are typically those with higher intelligence and earlier speech

Social Interaction Impairments Impairment in understanding & expressing non verbal behaviors (e.g., eye contact, facial expressions, body postures, gestures) Failure to develop peer relationships appropriately Lack of spontaneously sharing with others (joint attention) – lack of showing, pointing out objects of interest Early sign of language impairment Protoimperative gestures = gestures or vocalizations used to express needs Protodeclarative gestures = gestures or vocalizations directing someone’s attention to something of mutual interest Children with ASD use protoimperative gestures (e.g., pointing to a toy child wants), but NOT protodeclarative gestures (methods to engage other people in the interaction) However, children with ASD are more responsive to parents than unfamiliar adults

Communication Impairments Delay in spoken language (50% do not develop language) OR Impairment in ability to initiate / sustain conversation Atypical early vocalizations = early indicator of ASD in infants Unusual rhythm & intonation of speech Lack of make-believe play

Communication Impairments cont. Lack of social chatter – fail to use language for social communication Language is silly, nonsensical, incoherent, & irrelevant Pronoun reversal = child repeats personal pronoun exactly as heard, without changing pronoun to suit the situation Parent: “What’s your name?” Child (Tim): “Your name is Tim” Echolalia – parrot-like repetition of words or word combinations Parent: “Do you want a cookie?” Child: “Do you want a cookie?” Common element = failure to understand that language can be used to inform & influence other people

Restricted & Repetitive Behaviors & Interests Stereotyped, repetitive body movements or movements of objects (e.g., hand flapping, rocking, spinning) = self-stimulatory behaviors Children crave stimulation; self-stimulation serves to excites the nervous system OR Environment is too stimulating & these behaviors block out, control unwanted stimulation Inflexible adherence to routines / rituals, insistence on sameness Restricted, fixated interests that are abnormal in intensity or focus (e.g., preoccupation with objects) Hyper- or hyporeactivity to sensory input or unusual interest in sensory aspects of environment (e.g., indifference to pain/temp, adverse response to sounds or textures)

Theory of Mind ToM = ability to attribute mental states to oneself & others, understanding that others have beliefs, desires, & intentions different from one’s own Typically developing 4-year-olds have developed ToM They understand that someone can have a false belief about a situation Children with ASD get this puzzle wrong

Prevalence & Course 1-2% worldwide Dramatic increase in diagnosed cases Unsubstantiated proposed causes (e.g., vaccines, diet, allergies) Rise in prevalence likely due to: Greater awareness Greater recognition of milder forms of ASD Broadening of concept and definition Changes in diagnostic criteria & categories Diagnostic substitutions Is there a rise in prevalence rate due to some unidentified cause?

Prevalence & Course 4-5x more common in boys Sex difference most apparent among children average/above intelligence Among children with ASD & profound intellectual disability, numbers similar across sex Rates of ASD similar across racial & ethnic groups Higher prevalence among Caucasian children than African American & Hispanic children Cultures vary in view of ASD

Prevalence & Course Age of Onset Diagnosis usually made in preschool or later Most parents become concerned 1+ yrs before diagnosis Usually < 2nd birthday First concerns: Lack of progress in language, imaginative play, social relations Early indicators: Using few gestures to express social interest Not responding when name is called Lack of eye contact Limited babbling Odd or repetitive ways of moving hands/fingers AAP recommends all children be screened for ASD at 18-24 mo

Course 70% with ASD show poor outcomes long term and are unable to live independently Those with higher intellectual functioning have better prognosis

Causes Genetic Influences: Family & Twin Studies 15-20% of siblings of those with ASD also have the disorder Family members of children with ASD display higher rates of social & language deficits, unusual personality features Concordance rates for ASD Identical twins = 70-90% Fraternal twins = nearly 0% Heritability of an underlying liability may be as high as 90% However, greater role for environmental factors than previously thought

Causes Problems in Early Development Health problems during pregnancy, at birth, or immediately following birth Prenatal & neonatal complications preterm birth bleeding during pregnancy Toxemia viral infection Very preterm birth (<26 wks) Other risk factors affecting prenatal environment Parental age IVF Maternal use of drugs Toxic chemicals in the environment during pregnancy Maternal illness during pregnancy SSRI exposure during first trimester

Associated Characteristics Intellectual Deficits & Strengths 70% have intellectual impairment 40% severe to profound impairments, IQs < 50 30% mild to moderate impairments, IQ = 50-70 30% average to above-average intelligence Average or above average intelligence predicts independent living status as adults 25% develop splinter skills or islets of ability – special talent in spelling, drawing, memorization, music Above average for general population & well above own level of intellect 5% of children with ASD develop an isolated & remarkable talent = autistic savants

Treatment: Overview Best treatments developmentally oriented early behavioral interventions involving parents used along with special education These treatments associated with gains in Language Communication Measured IQ Modest reduction in severity of core symptoms Antipsychotic meds can help in decreasing interfering & challenging symptoms Meds have side effects; pros vs. cons should be weighed

Key Components of Behavioral Treatments for ASD (e.g., ABA) Early: Interventions should begin as soon a ASD diagnosis is seriously considered Intensive: Active engagement of child at least 25 hrs/week, 12 mo a year Low Student-Teacher Ratio: One-on-one time is important to meet individualized goals High Structure: Predictable routines, visual activity schedules, clear physical boundaries Family Inclusion: Include family component with parent training Peer Interactions: Promote opportunities for interactions with typically developing peers