Autism Spectrum Disorder

Autism Spectrum Disorder (ASD) is a common neurodevelopmental disorder characterized by deficits in social communication and by repetitive behaviors.  

ASD occurs in approximately 1 in 59 children.  

The behavioral characteristics of ASD present variably based on the age, cognitive abilities and language skills of the child.

The DSM-5 Criteria for ASD include:

A.  Persistent deficits in social communication and social interaction across multiple contexts all 3 of the following areas:

  • Social-emotional reciprocity (back-and-forth communication, sharing of interests, initiation of or response to interactions with others)
  • Nonverbal communicative behaviors used for social interaction (eye contact, body language, gestures, facial expressions)
  • Developing, maintaining and understanding relationships (interest in peers, adjusting behavior depending on social context, imaginative play)

B.  Restriced, repetitive patterns of behavior, interests, or activities in at least 2 of the following ways:

  • Stereotyped or repetitive movements, speech, or use of objects (lining up toys, echolalia)
  • Insistence on sameness, ritualized behavior patterns, or inflexible adherence to routines (difficulties with transitions, distress with small changes in routine, rigid thinking patterns)
  • Highly restricted, fixated interests (circumscribed or perseverative interest in unusual topics or objects)
  • Hyperreactivity or hyporeactivity to sensory stimuli or unusual interest in sensory environment (distress with specific sounds or textures, excessive smelling or touching objects)

The severity of ASD symptoms is defined in terms of 3 levels of required support.  These are Level 1, "Requiring support", Level 2, "Requiring substantial support", and Level 3, "Requiring very substantial support."

As deficits in social communication skills become more severe, individuals with ASD have less capacity to independently engage in the social interactions required to get basice needs met. 

Restricted and repetitive behaviors may become so consuming that they preclude other aspects of functioning, and inflexibility of behavior, difficulty coping with change, and extreme behavioral responses to interruptions in repetitive behaviors or changes in plan occur at higher levels of symptom severity.  

Screening & Evaluation

The AAP Clinical Report cited at the end of this page provides extensive guidance on the rationale and methods for screening, diagnosis, and work-up of children with ASD.   

The screening process is an extension of developmental surveillance at all well child visits and includes formal screening at ages 18 and 24 months.  Early screening should lead to early diagnosis and early implementation of therapeutic strategies that improve outcomes.  

The standard of care in most communities is to refer children who screen positive for ASD symptoms to a multidisciplinary clinic where formal diagnostic evaluations can be carried out.  Access to multidisciplinary formal diagnostic evaluations may be limited by geography, insurance, or waitlists for assessment that may be months or years long.  

In cases where a child clearly meets the criteria for an ASD diagnosis, it may be in the child's best interest for the pediatric clinician to give the diagnosis and write letters of recommendation for school-based supports and other services based on the ASD diagnosis.  

Psychiatric Symptoms & Comorbidities

Autism is a heterogenous condition.  Many individuals with autism are able to live independently and thrive professionally, particularly if they are surrounded by a culture of understanding, acceptance and support, and they have learned to negotiate social interactions.

Many children with ASD will require therapeutic interventions to help manage challenging behaviors and enhance social and communication skills.

Up to 70-90% of children with ASD will have a co-occuring psychiatric disorder, including ADHD, an anxiety disorder, OCD, or a mood disorder.  Screening for mental health disorders in children and adolescents with ASD should occur as for neurotypical children.  

There may be overlap betwen core ASD symptoms and those of another psychiatric disorder.  Diagnostic patterns in ASD have changed over time.  Prior to DSM-5, ADHD could not be diagnosed in an individual with ASD.  DSM-5 allows for the comorbid diagnoses of ASD and ADHD.

The first step in partnering with children with ASD and their families to address challenging behaviors is "detective work" - figuring out possible causes of the behavior.  

The differential diagnosis for new-onset or chronic behavioral symptoms in children with ASD includes:

  • Medical problems such as otitis media, constipation, GERD, dental pain, menstrual pain or distress, or injuries 
  • Communication: being unable to communicate verbally or through augmented communication can be frustrating.  Children with ASD may lash out behaviorally when they cannot make their needs or preferences known.  
  • Behavioral reinforcement: Behaviors that persist tend to be self-reinforcing.  Children with ASD may have decreased problem-solving skills.  Behaviors will be reinforced if they:
    • Are positively reinforced – they result in attention, access to preferred items, activities or people
    • Are negatively reinforced – they result in escape from or avoidance of unwanted experiences
    • Are internally reinforced – they are self-stimulating, or reduce pain, or provide comfort
  • Medication side effects: Stimulants, antiepileptics, muscle relaxants, centrally acting antiemetics and other medications can have behavioral side effects.
  • Cognitive and sensory factors:  A mismatch between academic or performance expectations and a child’s cognitive or adaptive abilities can be stressful and present as behavioral disturbance.  Individuals with ASD may have sensory sensitivities and can be overwhelmed in environments with excessive noise, light, or other stimuli.  
  • Environmental and psychosocial factors: Children and adolescents with ASD will generally do best in predictable environments where they can be expected to function at their developmental level.  Many individuals with ASD are sensitive to changes in environment or routine and will exhibit behavioral symptoms if these occur.  
  • Children and adolescents with ASD are at high risk for bullying, trauma and abuse


Interventions and Therapies

Many children with ASD receive the majority of their therapeutic interventions in the school system. These may include speech and occupational therapies and assited communications.

Developmental models for ASD intervention are focused on teaching adults to engage in nondirective interactive strategies to foster interaction and  communication in the context of play. One such approach is known as DIRFloortime (The Developmental, Individual Differences, and Relationship-Based model).

Applied Behavioral Analysis is an intensive therapy that examines the antecedents and reinforcers of problematic behaviors and works with patients and caregivers in reducing these with behavioral strategies.

Pharmacologic Treatments

While there is no medication that treats all core symptoms of ASD, essentially every class of psychotropic medication has been studied in ASD populations.  The following is a summary of the evidence for pharmacologic strategies targeting specific symptom clusters in children and adolescents with ASD.

Target: Irritability, Aggression, and Self-Injury

Atypical Antipsychotics: Risperidone and aripiprazole have both been found effective in randomized controlled trials for the treatment of irritability, aggression and self-injury in school-aged children with ASD.

Smaller studies have shown risperidone to be less effective in reducing irritability and aggression and to have a higher side effect burden in preschool-aged children with ASD.

Based on these studies, risperidone was approved by the FDA for treatment of aggressive behavior in children aged 5 years and up with pervasive developmental disorders in 2005. Aripiprazole was granted FDA approval for the treatment of irritability and aggression in patients aged 6 years and up 2009.

Other antipsychotic medications have been found ineffective or not been studied adequately to support their use in targeting aggression and irritability in ASD.

Atypical antipyschotic medications are associated with weight gain, adverse metabolic and endocrine effects, and dystonic reactions.  Children treated with atypical antipsychotics for aggression may develop food seeking behaviors that are as problematic as the aggressive behavior the medication was meant to target.   

Antipsychotic medications should be used in conjunction with behavioral therapies.  Antipsychotic medications should not be used indefinitely.

Target: Hyperactivity and Impulsivity

Stimulants: The only randomized controlled trial of stimulants was conducted by the Research Units in Pediatric Psychopharmacology group, or RUPP, in 2005. Overall, methylphenidate was less effective, and effective in a smaller percentage of patients in this trial than in trials of stimulants in neurotypical children. Additionally, 18% of patients had increased irritability with methylphenidate.

Atomoxetine: A randomized controlled trial of atomoxetine, or Strattera, in 97 children and adolescents with ASD resulted in minimal to moderate improvement in hyperactivity symptoms (Harfterkamp 2012).

The alpha-agonists appeared to be effective in a few small studies of immediate-release clonidine and guanfacine. A randomized controlled trial of  compared 31 children on guanfacine extended-release with 31 children on placebo for 8 weeks. The modal dose was 3 mg. Children on guanfacine extended release showed a 44% decrease in hyperactivity symptoms as compared to 13% on placebo. The most common side effects were drowsiness and fatigue (Politte 2018). 

Overall, the evidence most strongly supports alpha-agonists for the management of hyperactivity and inattention in children with ASD.

Target: Sleep Onset and Sleep Duration

In terms of pharmacotherapy, melatonin is the only well-studied pharmacologic treatment for sleep disturbance in children and adolescents with ASD. Immediate-release melatonin is safe and effective in improving sleep latency, and to a lesser extent, total sleep time (Gringas 2012, Malow 2012). Doses in trials were 1-3 mg nightly.

Target: Repetitive Behaviors

Randomized controlled trials of selective serotonin reuptake inhibitors (SSRIs) in children and adolescents with ASD have shown only modest improvement in repetitive behaviors (Hollander 2012; King 2009). Behavioral activation with SSRIs was a concern in 2 of the studies.

Target: Social relatedness

Pharmacologic strategies to improve social relatedness in ASD have generally been unsuccessful and studies have been of poor quality and no significant improvement has been observed. Trials have included naltrexone, lamotrigine, amantadine and d-cycloserine.

Oxytocin showed initial promise in randomized controlled trials measuring social relatedness but negative studies followed, and a recent meta-analysis showed no difference from placebo. (Ooi 2017; Bernaerts 2020)


Resources for Families

Autism Speaks - includes behavioral health guides and videos for families 

Autism Navigator - A virtual community for families

AAP Autism Resources

AACAP Autism Resources

Resources for Clinicians

Psychopharmacology in Children with Autism Spectrum Disorder
in Primary Care (RAMP resource)  Watch & Listen | Download & Read

International Society for Autism Research


Identification, Evaluation and Management of Children with Autism Spectrum Disorder (pdf) AAP Clinical Report/Guidance for the Clinician in Rendering Pediatric Care

Arnold, L. E., Aman, M. G., Li, X., Butter, E., Humphries, K., Scahill, L., Lecavalier, L., McDougle, C. J., Swiezy, N. B., Handen, B., Wilson, K., & Stigler, K. A. (2012). Research Units of Pediatric Psychopharmacology (RUPP) autism network randomized clinical trial of parent training and medication: One-year follow-up. Journal of the American Academy of Child and Adolescent Psychiatry, 51(11), 1173–1184.

Bernaerts, S., Boets, B., Bosmans, G., Steyaert, J., & Alaerts, K. (2020). Behavioral effects of multiple-dose oxytocin treatment in autism: A randomized, placebo-controlled trial with long-term follow-up. Molecular Autism, 11(1), 6.

Gringras, P., Nir, T., Breddy, J., Frydman-Marom, A., & Findling, R. L. (2017). Efficacy and Safety of Pediatric Prolonged-Release Melatonin for Insomnia in Children With Autism Spectrum Disorder. In J Am Acad Child Adolesc Psychiatry (Vol. 56, Issue 11, pp. 948-957.e4).

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Hollander, E., Soorya, L., Chaplin, W., Anagnostou, E., Taylor, B. P., Ferretti, C. J., Wasserman, S., Swanson, E., & Settipani, C. (2012). A Double-Blind Placebo-Controlled Trial of Fluoxetine for Repetitive Behaviors and Global Severity in Adult Autism Spectrum Disorders. American Journal of Psychiatry, 169(3), 292–299.

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Ooi, Y. P., Weng, S.-J., Kossowsky, J., Gerger, H., & Sung, M. (2017). Oxytocin and Autism Spectrum Disorders: A Systematic Review and Meta-Analysis of Randomized Controlled Trials. Pharmacopsychiatry, 50(1), 5–13.

Politte, L. C., Scahill, L., Figueroa, J., McCracken, J. T., King, B., & McDougle, C. J. (2018). A randomized, placebo-controlled trial of extended-release guanfacine in children with autism spectrum disorder and ADHD symptoms: An analysis of secondary outcome measures. In Neuropsychopharmacology (Vol. 43, Issue 8, pp. 1772–1778).

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Zhou, M. S., Nasir, M., Farhat, L. C., Kook, M., Artukoglu, B. B., & Bloch, M. H. (2021). Meta-analysis: Pharmacologic Treatment of Restricted and Repetitive Behaviors in Autism Spectrum Disorders. In J Am Acad Child Adolesc Psychiatry (Vol. 60, Issue 1, pp. 35–45).