What are the levels of Autism Spectrum Disorder (ASD) and how is it managed?

Autism Spectrum Disorder Severity Levels and Management

ASD Severity Classification

The American Academy of Child and Adolescent Psychiatry defines three distinct severity levels for Autism Spectrum Disorder based on the amount of support required across two core domains: social communication/interaction and restricted, repetitive behaviors. 1

Level 3: Requiring Very Substantial Support

• Severe deficits in verbal and nonverbal social communication skills 1
• Inflexibility of behavior that markedly interferes with functioning in all spheres 1
• Represents the most severe presentation requiring intensive, continuous support 1

Level 2: Requiring Substantial Support

• Marked deficits in verbal and nonverbal social communication skills 1
• Inflexibility of behavior that interferes with functioning in a variety of contexts 1
• Requires consistent, substantial intervention across multiple settings 1

Level 1: Requiring Support

• Deficits in social communication that cause noticeable impairments 1
• Inflexibility of behavior that causes significant interference with functioning in one or more contexts 1
• Represents the mildest presentation but still requires targeted support 1

Critical Assessment Considerations

• Each domain (social communication and restricted/repetitive behaviors) is rated separately, allowing for different severity levels across the two domains 1
• The severity specifier must account for both current presentation and response to intervention, considering historical symptoms that may not be currently present due to intervention or development 1

Management Approach by Severity Level

First-Line Treatment: Behavioral Interventions (All Levels)

Structured behavioral and educational interventions are the first-line treatments for all severity levels of ASD, with pharmacotherapy reserved for specific target symptoms when behavioral approaches are insufficient. 2

Applied Behavioral Analysis (ABA) - Well-Established Evidence

• Individual, comprehensive ABA is classified as well-established treatment 3
• Teacher-implemented, focused ABA combined with developmental social-pragmatic approaches is well-established 3
• Early Intensive Behavioral Intervention based on ABA principles has shown effectiveness for young children with ASD and can address motivational deficits through structured reinforcement 2
• Functional analysis of target behaviors should be performed to identify patterns of reinforcement and develop appropriate behavioral techniques 2

Developmental Social-Pragmatic Approaches

• Focused developmental social-pragmatic parent training is classified as probably efficacious 3
• Individual, focused ABA combined with developmental social-pragmatic approaches is probably efficacious 3
• The Early Start Denver Model demonstrates small to medium effect sizes for improvement in language, play, and social communication in children 5 years or younger 4

Educational Interventions (All Levels)

Structured educational programs must involve planned, intensive, individualized intervention with an experienced, interdisciplinary team and family involvement to ensure generalization of skills. 2

• Programs should use explicit teaching methods tailored to the individual's cognitive profile 2
• The educational plan must reflect an accurate assessment of the individual's strengths and vulnerabilities, with explicit description of services, goals, and monitoring procedures 2
• Two structured educational models with demonstrated efficacy are the Early Start Denver Model and the Treatment and Education of Autism and related Communication handicapped Children (TEACCH) program 2

Communication Interventions (Particularly Levels 2-3)

For individuals who do not yet use words or have limited verbal communication, alternative communication modalities should be implemented immediately. 2

• Evidence supports the use of Picture Exchange Communication System, sign language, activity schedules, and voice output communication aids 2
• Speech/language therapy is essential for individuals with significant language and communication challenges 2
• For individuals with fluent speech but impaired pragmatic language skills, explicit teaching of social reciprocity and pragmatic language skills is recommended 2
• Augmentative/alternative communication devices should be considered for individuals with substantial functional communication needs 2

Pharmacological Management (Adjunctive for All Levels)

Pharmacotherapy is indicated for co-occurring psychiatric conditions such as emotion dysregulation or attention-deficit/hyperactivity disorder, not for core ASD symptoms. 4

For Irritability and Aggression

• Risperidone and aripiprazole can improve irritability and aggression with a standardized mean difference of 1.1 (large effect size) compared with placebo 4
• These medications are associated with adverse effects including changes in appetite, weight, and sleep 4

For Co-occurring ADHD

• Psychostimulants are effective for attention-deficit/hyperactivity disorder with a standardized mean difference of 0.6 (moderate effect size) compared with placebo 4
• Attentional difficulties are frequent in autism and may reflect cognitive, language, and social problems 2

For Depression and Anxiety

• Evaluate for comorbid conditions that may include depression and anxiety, particularly in adolescents with higher-functioning ASD 2
• Compared with people without ASD, individuals with ASD have higher rates of depression (20% vs 7%) and anxiety (11% vs 5%) 4

Multidisciplinary Assessment Requirements (All Levels)

Psychological assessment, including measurements of cognitive ability and adaptive skills, should be conducted to frame social-communication difficulties and guide treatment planning. 2

• Occupational and physical therapy evaluations are needed to address sensory and motor difficulties 2
• For individuals with significant cognitive, functional, and social difficulties, initial cognitive and functional evaluations should be done to optimize therapy targets 2
• Assessment tools such as the Verbal Behavior Milestones Assessment and Placement Program (VB-MAPP) or the Assessment of Basic Language and Learning Skills-Revised (ABLL-R) can enhance target selection 2

Common Pitfalls to Avoid

Be aware of diagnostic overshadowing—the tendency to fail to diagnose comorbid conditions when a more noticeable condition (like ASD) is present. 2

• Nearly 75% of ASD patients suffer from comorbid psychiatric illnesses or conditions, which may include ADHD, anxiety, bipolar disorder, depression, and Tourette syndrome 5
• Individuals with ASD have higher rates of sleep difficulties (13% vs 5%) and epilepsy (21% with co-occurring intellectual disability vs 0.8%) compared with those without ASD 4
• Recognize that apparent behavioral symptoms may be manifestations of communication difficulties rather than primary symptoms, particularly in nonverbal or minimally verbal individuals 2