Assessment section of the Autism Spectrum Disorders Evidence Map for pertinent scientific evidence, expert opinion, and client/caregiver perspective.
Interdisciplinary collaboration and family involvement are essential in assessing and diagnosing ASD. The SLP is a key member of an interdisciplinary team that includes the child's pediatrician, a pediatric neurologist, and a developmental pediatrician. There are a number of available algorithms and tools to help physicians develop a strategy for early identification of children with ASD (Plauché Johnson & Myers, 2007).
Consistent with the World Health Organization's (WHO) International Classification of Functioning, Disability, and Health framework (ASHA, 2016a; WHO, 2001), assessment is conducted to identify and describe
- impairments in body structure and function, including underlying strengths and weaknesses related to ASD that affect communication performance;
- co-morbid deficits or conditions, such as developmental disability, genetic syndromes, or hearing loss;
- limitations in activity and participation, including functional communication in everyday communication contexts;
- contextual (environmental and personal) factors that serve as barriers to or facilitators of successful communication and life participation; and
- the impact of communication impairments on the individual's quality of life.
See ASHA's resource on the
International Classification of Functioning, Disability and Health (ICF) for examples of ICF handouts specific to selected disorders.
An early, accurate diagnosis of ASD can (a) help families and caregivers access appropriate services, (b) provide a common language across interdisciplinary teams, and (c) establish a framework to help families and caregivers understand the child's difficulties. Any diagnosis of ASD—particularly of young children—is periodically reviewed by members of the interdisciplinary team because diagnostic categories and conclusions may change as the child develops.
The identification of early behavioral indicators can help families and caregivers obtain appropriate diagnostic referrals and access early intervention services, even before a definitive diagnosis is made (Woods & Wetherby, 2003). Furthermore, early intervention can improve long-term outcomes for many children (Dawson & Osterling, 1997; Dawson et al., 2010; Harris & Handleman, 2000; Landa & Kalb, 2012). A number of researchers have been reporting the benefits of providing intervention to at-risk infants that targets pre-linguistic communication (Bradshaw et al., 2015; Koegel et al., 2014).
Awareness of individual and cultural differences is essential for accurate diagnosis. For example, direct eye contact with an authority figure may be considered disrespectful in some cultures, and silence may be valued as a sign of respect. In a U.S. school system, these behaviors could easily be misinterpreted as socially inappropriate.
The core characteristics of ASD may be viewed through a cultural lens leading to under-, over-, or misdiagnosis (Taylor Dyches et al., 2001; Tek & Landa, 2012). Signs and symptoms that are clearly "red flags" in the U.S. health care or educational system may not be viewed in the same way by someone from a culture that does not formally define the disorder.
Cultural and linguistic variables may contribute to the disparity in the diagnosis of ASD among some racial/ethnic groups (Begeer et al., 2009; Taylor Dyches, 2011). For example, Begeer et al. (2009) found that Dutch pediatricians might be inclined to attribute social and communication problems of non-European minority groups to their ethnic origin, while attributing these same characteristics to autistic disorders in children from majority groups.
Cultural and linguistic factors can affect the family's reaction to an ASD diagnosis and their decisions regarding services (Wilder et al., 2004). For example, some cultures view disability in a negative light and feel that it needs to be hidden from others; this, in turn, may influence the type of care that the family seeks. See ASHA's Practice Portal page on
Cultural Competence. See also Taylor Dyches (2011) for a discussion of diverse perspectives on symptoms of autism.
The goal of screening is to detect developmental delays that might signal ASD in high-risk populations, such as children referred to the early intervention system or younger siblings of children with autism. See ASHA's Practice Portal page on
Screening tools for early identification are available, including one that can be used to identify pre-linguistic behavioral vulnerabilities in infants from 6 to 18 months of age (Bryson et al., 2008) and a broadband screener to identify communication delays (including ASD) in children from 9 to 24 months of age (Pierce et al., 2011; Wetherby et al., 2008). Questionnaire-based tools to screen children at risk for ASD as early as 12 months of age are also available (Turner-Brown et al., 2012). Any screening tool should be culturally and linguistically appropriate and have strong psychometric features to support its accuracy.
Screening typically includes
- norm-referenced parent and teacher report measures,
- competency-based tools, such as interviews and observations, and
- hearing screening to rule out hearing loss as a contributing factor to communication and behavior difficulties.
Screening procedures evaluate the main characteristics that differentiate ASD from other developmental disorders, including difficulties in
- eye gaze,
- orienting to one's name,
- pointing to or showing objects of interest,
- pretend play,
- nonverbal communication, and
- language development.
Social communication norms vary across cultures. When screening is conducted for nonlinguistic aspects of communication, it is important to recognize when differences are related to cultural variances rather than to a communication disorder. See ASHA's Practice Portal page on
Loss of language or social skills at any age should be considered grounds for screening. In cases where children are being raised in a bilingual environment, consider whether language loss is attributable to language attrition. See ASHA's Practice Portal page on
Bilingual Service Delivery.
Because children with ASD are often initially suspected of having a hearing problem, audiologists play a critical role in recognizing possible signs of ASD in children whose hearing they test and making appropriate referrals for screening.
Individuals suspected of having ASD on the basis of screening results are referred to an SLP and other professionals, as needed, for a comprehensive assessment. Assessment should be functional and sensitive to the wide range of acceptable social norms within and across communities and cultures. It should involve the collaborative efforts of families, caregivers, classroom teachers, SLPs, special educators, and psychologists, as needed.
The SLP incorporates the family's perspective into the assessment and effectively elicits information about their beliefs and concerns. It is important to convey information to families clearly and empathetically, as the assessment and diagnosis process is likely to be stressful and emotional (Marcus et al., 2005).
The comprehensive assessment for individuals suspected of having ASD typically includes the following:
- Relevant case history, including information related to the child's health, developmental and behavioral history, and current medical status.
- Medical and mental health history of the family, including history of siblings with ASD.
- Medical evaluations, including general physical and neurodevelopmental examination and vision testing.
- Formal and informal assessments by an SLP, including
- language assessment
- speech assessment, including assessment of motor speech abilities,
- feeding and swallowing assessment, as needed, and
- AAC assessment (as needed) to determine the potential benefits for improving functional communication.
- Audiologic assessment by an audiologist.
The comprehensive assessment may also include
- genetic testing—particularly if there is a family history of intellectual disability or genetic conditions associated with ASD (e.g., fragile X, tuberous sclerosis) or if the child exhibits physical features that suggest a possible genetic syndrome; and
- metabolic testing—if the child exhibits symptoms such as lethargy, cyclic vomiting, pica, or seizures.
The comprehensive assessment may result in
- a diagnosis of ASD;
- a description of the characteristics and severity of communication-related symptoms;
- recommendations for intervention, goals, and supports;
- a referral for AAC assessment, if not completed as part of the comprehensive assessment; and/or
- referral to other professionals for additional data to confirm a diagnosis of ASD or for further testing if other disorders/conditions are suspected.
Whenever a diagnosis of ASD is given, it is essential that this be done with the utmost sensitivity. See ASHA's Practice Portal page on
Counseling for Professional Service Delivery.
The SLP can use both formal and informal assessment approaches. Formal testing may be required if a diagnosis or eligibility for services has yet to be determined. Informal testing may be most useful in determining whether specific communication milestones have been met or for assessing communication skills in everyday settings. See ASHA's resource on
assessment tools, techniques, and data sources that may be used in a comprehensive communication assessment.
Dynamic assessment may be used to identify nonsymbolic and symbolic communication behaviors and to evaluate individual learning potential (Pea, 1996; Snell, 2002).
A comprehensive speech-language assessment includes testing of skills in language, speech, feeding and swallowing, and augmentative and alternative communication (AAC).
Language. Depending on the individual's age and abilities, the SLP assesses the following language skills:
- Spoken language—this includes language expression and language comprehension (see ASHA's Practice Portal page on
Spoken Language Disorders). All means of expressive language—verbal (including echolalia) and nonverbal (including gestures)—should be assessed for communicative function and intent (see, e.g., Stiegler, 2007). See ASHA's resource on
echolalia and its role in gestalt language acquisition.
- Written language—this includes reading decoding, reading comprehension, written expression, and writing for varied audiences (see ASHA's Practice Portal page on
Written Language Disorders).
- Social Communication—this includes
- use of gaze;
- joint attention;
- sharing affect;
- initiation of communication;
- social reciprocity and the range of communicative functions;
- play behaviors;
- understanding and use of facial expressions;
- use of gestures;
- speech prosody (using stress and intonation to effectively convey meaning); and
- conversational skills, including
- topic management (initiating, maintaining, and terminating relevant, shared topics);
- turn-taking; and
- providing appropriate amounts of information in conversational contexts.
(See ASHA's Practice Portal page on
Social Communication Disorders and ASHA's resource on
social communication benchmarks [PDF].)
Speech. A speech assessment is important for determining the presence or absence of a speech sound disorder (including a motor speech disorder). See ASHA's Practice Portal pages on
Speech Sound Disorders: Articulation and Phonology and
Childhood Apraxia of Speech.
A speech sound disorder can result in a person having significant difficulty producing speech—or, possibly, an inability to speak. Without an accurate diagnosis, significant speech difficulties might be attributed mistakenly to language and communication problems associated with ASD. For example, when a speech sound disorder results in lack of speech or highly unintelligible speech, someone might assume that the individual is nonverbal—when, in fact, they have average to above-average language and communication abilities (see, e.g., Tierney et al., 2015). Therefore, it is important to accurately diagnose and address co-morbid speech sound disorders, in addition to addressing the language and communication difficulties associated with ASD.
Feeding and swallowing. See ASHA's Practice Portal page on
Pediatric Feeding and Swallowing.
Augmentative and alternative communication (AAC). See ASHA's Practice Portal page on
Augmentative and Alternative Communication.
Following a diagnosis of ASD, ongoing assessment is conducted to
- determine an individual's current profile of social communication skills,
- identify high-priority learning objectives within natural communication contexts, and
- examine the influence of the communication partner and the environment on communication competence.
As part of the ongoing assessment process, clinicians can use
dynamic assessment procedures to identify skills that an individual has achieved, those that may be emerging, and the contextual supports that enhance communication skills (e.g., AAC or modeling). See ASHA's resource on
intervention goals associated with core challenges in ASD [PDF].
Individuals with hearing loss may present with symptoms similar to those of ASD, particularly in the areas of communication and socialization. For example, in the case of children with significant hearing loss or deafness,
- the inability to hear may limit social interaction with peers and may lead to the kinds of social skills deficits often seen in children with ASD, and
- when compared to peers with normal hearing, the speech of children with hearing loss or deafness may be different, and they may rely more heavily on gestures (Worley et al., 2011).
It is also possible for an individual to have both ASD and hearing impairment (Easterbrooks & Handley, 2005; Malandraki & Okalidou, 2007; Szymanski & Brice, 2008). The potential similarities in symptoms between hearing impairment and ASD, and the possibility that both might be present, can make diagnosis challenging.
Also, some characteristic behaviors associated with ASD can make it challenging to obtain valid and reliable hearing assessment results. These include (a) comfort with sameness and aversion to novel situations; (b) hypersensitivity and negative responses to sensory input; and (c) communication differences, such as receptive language deficits and unreliable pointing gestures (Davis & Stiegler, 2005; Stiegler & Davis, 2010).
Suggestions for assessing hearing in individuals with these and other challenging behaviors include
- minimizing distractions in the test suite;
- using visual schedules to support audiological testing sequence;
- partnering with parents and the managing SLP, all of whom are more familiar with the individual's behaviors, interests, and needs;
- using the individual's primary/preferred language form (e.g., spoken language, sign, AAC devices, or picture symbols);
- increasing the individual's familiarity with assessment procedures prior to testing, such as through the use of social stories (Gray et al., 2002), a visual schedule, and/or practicing with a favorite doll or stuffed animal;
- allowing the individual to touch and explore earphones that will be used during testing to help them overcome tactile sensitivity and related anxiety;
- incorporating flexibility in the assessment situation (e.g., testing order or earphone type);
- practicing appropriate motor movements in response to test stimuli;
- knowing what is reinforcing to the individual (e.g., food, clips from favorite videos, playing with a favorite toy) and using these reinforcers to reward appropriate behavioral responses to test stimuli;
- considering the use of multiple sessions to obtain complete results;
- being aware of the individual's signs of distress and terminating testing before the situation escalates (Brueggeman, 2012; Davis & Stiegler & Davis, 2010);
- considering the use of alternative behavioral stimuli, such as the child's favorite sounds (e.g., unwrapping a candy wrapper outside of the child's vision); and
- considering the need for auditory brainstem response (ABR) testing when behavioral audiometry is not possible.
Scope of Practice in Audiology (ASHA, 2018c).
Considerations in the School Setting
Within a public school setting, eligibility for services under the disability category of autism is based on the definition provided in the Individuals with Disabilities Education Improvement Act of 2004 (IDEA, 2004):
Autism means a developmental disability significantly affecting verbal and nonverbal communication and social interaction, generally evident before age 3, which adversely affects a child's educational performance. Other characteristics often associated with autism are engagement in repetitive activities and stereotyped movements, resistance to environmental change or change in daily routines, and unusual responses to sensory experiences. The term does not apply if a child's educational performance is adversely affected primarily because the child has an emotional disturbance as defined by IDEA criteria.
A child who manifests the characteristics of "autism" after age 3 could be diagnosed as having "autism" if the criteria in the preceding paragraph are met.
34 C.F.R. ß 300.7(c)(1)
Social communication challenges affect participation and progress in the general education curriculum. The pervasive nature of these challenges in individuals with ASD supports the criteria for eligibility for services in the schools (IDEA, 2004).
Individuals diagnosed with ASD using other sources of clinical criteria, such as the DSM-5 (APA, 2013), are likely to be eligible for special education services under the autism category, as defined above, due to deficits in social communication functioning across severity levels.
Inappropriate Exclusion of Services
IDEA (2004) mandates that "a priori" criteria should be avoided when making decisions about eligibility for services. These criteria are listed below, with reference to ASD as relevant.
Cognitive referencing. This practice of comparing IQ scores and language scores to determine eligibility for speech-language intervention assumes that language functioning cannot surpass cognitive levels. Consequently, if language functioning is commensurate or consistent with cognitive skills, no further gains can be made through intervention. Research had demonstrated that children with disabilities whose language and cognitive levels were commensurate nonetheless benefit from language intervention (Cole et al., 1990).
Chronological age. This argument suggests that individuals with disabilities are either "too young" or "too old" to benefit from communication services. However, research shows that infants, toddlers, and preschoolers with ASD do benefit from communication services and supports (Garfinkle & Schwartz, 2002; Koegel et al., 2014; Lawton & Kasari, 2012; Pierce et al., 2011). In addition, individuals with ASD can continue to develop communication abilities across their lifespan (Hamilton & Snell, 1993; Pickett et al., 2009; Watanabe & Sturmey, 2003).
Diagnostic label. The term "severe disability" is used to describe a variety of diagnostic labels that result in significant communication impairment. However, research shows that individuals with severe disabilities—regardless of the underlying diagnosis—can learn to communicate effectively. In the case of ASD, social communication impairment is a core feature (Baron-Cohen et al., 1992; DiLavore et al., 1995; Lord & Corsello, 2005). Therefore, a diagnosis of ASD indicates the inclusion of communication services. Research has indeed demonstrated the benefits of instruction and support for individuals with ASD (Hamilton & Snell, 1993; Mirenda et al., 2000; Wetherby et al., 2000).
Absence of cognitive or other prerequisite skills. This practice posits that certain skills and performance criteria are necessary to benefit from communication services and supports, based on an interpretation of some research findings (Miller & Chapman, 1980; Shane & Bashir, 1980). However, subsequent research shows that individuals (including those with ASD) who do not demonstrate supposed prerequisites can benefit from appropriate communication services and supports (Amato et al., 1999; Bondy & Frost, 1998; Moes & Frea, 2002).
Failure to benefit from previous communication services. Lack of progress in therapy is often attributed to a lack of "potential" to benefit from services. But lack of progress can be tied to other factors, including inappropriate goals, unsuitable intervention methods, failure to incorporate assistive technology, or insufficient methods in measuring outcomes (National Joint Committee for the Communication Needs of Persons with Severe Disabilities, 2003). Access to communication services and supports should not be denied because of failure to progress as a function of these other factors. Rather, previously unsuccessful therapy experiences should be examined to help determine ways in which communication services and supports can better be tailored to meet the individual's unique communication needs.
Lack of funding or adequately trained personnel. Lack of funding and expertise often fuels exclusionary practices. If trained personnel are not available, then there is an obligation either to find trained personnel or to train existing personnel (Timothy W. v. Rochester, New Hampshire School District, 1989). Similarly, lack of funding does not constitute a reason for exclusion from communication services and supports. IDEA (2004) mandates that identified needs must be met.
High-functioning individuals with ASD pose particular challenges—both for identification and for determining eligibility for services. These individuals often have either verbal or nonverbal intelligence within or above the average range and appear to succeed in some or most academic subjects, particularly in early school years. As a result, many are not diagnosed until later school age, adolescence, or even adulthood.
Long-term outcomes for these individuals show that challenges with social engagement and social communication can significantly affect their ability to adjust to social demands in later academic and community settings and in the workplace (Gilchrist et al., 2001; Mueller et al., 2003; Tsatsanis et al., 2004). These findings suggest the importance of providing intervention to address the gap between cognitive potential and social adaptive functioning.
Determining eligibility for educational services requires using a variety of strategies for gathering information, including
- standardized measures of social adaptive functioning,
- naturalistic observation across a range of settings, and
- caregiver/teacher interviews or questionnaires.
Regardless of the assessment measures or tools used, the clinician needs to be aware of any subtle signs and symptoms consistent with a diagnosis of ASD.
Some adults are diagnosed with ASD as children. Others have lived with undiagnosed ASD and seek services only when they start experiencing challenges at work, in social relationships, or in academic settings (Brugha et al., 2011). Some individuals may find a diagnosis of ASD in adulthood a relief. But for many, it can come as a surprise and may be difficult to accept, even if it helps explain some of the challenges they have been experiencing. Therefore, it is essential to give the diagnosis with the utmost sensitivity. See ASHA's Practice Portal page on
Counseling for Professional Service Delivery.
Adult diagnosis is complicated by the fact that there is limited information about how the core characteristics of ASD manifest in adults, and there are no standard screening and diagnostic tools for ASD in adults (IACC, 2017). The importance of involving professionals from multiple disciplines cannot be overstated, especially because many adults receiving an ASD diagnosis for the first time can have other related concerns (e.g., mental health; Geurts & Jansen, 2012). SLPs with expertise in assessing social communication, higher-level language, conversation, and discourse are integral members of this team.
For a comprehensive discussion of individuals with ASD as they transition into and through adulthood, see