Autism spectrum disorder

Autism spectrum disorder, previously called autistic disorder, Asperger syndrome, or pervasive developmental disorder not otherwise specified, now all given diagnosis of ASD, leading to a very heterogenous population (Lord, Baird, and Veenstra-Vanderweele, 2018)

- Core features include:

1) social communication deficits and

2) repetitive / unusual sensory-motor behaviors

DSM-5 Diagnostic criteria - signs and symptoms of ASD as described in DSM-5 (must be present in early developmental period, must lead to clinically significant impairment in social, occupational, or other areas of functioning)52

1) Persistent deficits in social communication and social interaction across multiple contexts, as manifested by (MUST HAVE ALL 3 SUBDOMAINS):

a. Deficits in social-emotional reciprocity

i. e.g., abnormal social approach and failure of normal back-and-forth conversation,

ii. or reduced sharing of interests, emotions, or affect

b. Deficits in non-verbal communicative behaviors

i. e.g., poorly integrated verbal and nonverbal communication,

ii. abnormalities in eye contact and body language,

iii. or deficits in understanding and use of gestures

c. Deficits in developing, maintaining, and understanding relationships

i. e.g., difficulties adjusting behavior to suit various social contexts;

ii. or difficulties in sharing imaginative play or making friends

2) Restricted, repetitive patterns of behavior, interests, or activites, as manifested by (MUST HAVE AT LEAST 2 SUBDOMAINS):

a. Stereotyped or repetitive motor movements, use of objects, or speech

i. e.g., simple motor stereotypies

ii. lining up toys

iii. flipping objects

b. Insistence on sameness, inflexible adherence to routines, or ritualized patterns of verbal and nonverbal behavior

i. e.g., extreme distress at small changes,

ii. difficulties with transitions,

iii. or rigid thinking patterns

c. Highly restricted, fixated interests that are abnormal in intensity or focus

i. e.g., strong attachment to or preoccupation with unusual objects

d. Hyperreactivity or hyporeactivity to sensory input, or unusual interests in sensory aspects of the environment

i. e.g., apparent indifference to pain or temperature,

ii. or adverse responses to specific sounds or textures

- Several self-report screeners for ASD in adults are available, but their validity is questionable due to low specificity (Lord, Baird, and Veenstra-Vanderweele, 2018)

Treatment

- in children, early intensive behavioral intervention (such as applied behavior analysis, or ABA); alternatively there are naturalistic developmental behavioral interventions (NDBI) that has similarities to ABA but emphasizes play, social interaction, communicative initiation on the part of the child, and natural consequences as opposed to rewards such as food (Lord, Baird, and Veenstra-Vanderweele, 2018)

- be aware of comorbidities when treating ASD: (Lord, Baird, and Veenstra-Vanderweele, 2018)

• ADHD is common (28%)
• Anxiety, especially social anxiety and separation anxiety, is common.
• 15 – 65% have IQ < 70.
• Speech and language delays exist in about 87% in 3 year olds with ASD.
• Epilepsy has prevalence of 8.6%.

- Pharmacologic trials have only FDA approval in children and adolescents only, they include: (Lord, Baird, and Veenstra-Vanderweele, 2018)

• risperidone
  • target symptoms: agitation or irritability in ASD
  • effect size: 0.94
  • common adverse effects: increased appetite, sedation, weight gain
• aripiprazole
  • target symptoms: agitation or irritability in ASD
  • effect size: 0.87
  • common adverse effects: nausea, weight gain
• atomoxetine
  • target symptoms: typically for ADHD symptoms
  • effect size: 0.68 - 0.84
  • common adverse effects: decreased appetite, nausea, irritability
• methylphenidate
  • target symptoms: ADHD
  • effect size: 0.78
  • common adverse effects: sleep disruption, decreased appetite
• guanfacine
  • target symptoms: ADHD
  • effect size: 1.67
  • common adverse effects: fatigue, sedation, decrease HR and BP

References

American Psychiatric Association. Diagnostic and statistical manual of mental disorders: DSM-5 (5th ed.). (American Psychiatric Association).

Lord, C., Elsabbagh, M., Baird, G. & Veenstra-Vanderweele, J. Autism spectrum disorder. The Lancet 392, 508–520 (2018). https://pubmed.ncbi.nlm.nih.gov/30078460/