Autism diagnosis in a complex systemic and cultural landscape: A clinical perspective

Clinical and systemic context

Referrals to autism diagnostic services are increasingly for individuals ¹ with non-specific emotional, behavioural, academic or other functioning concerns, posing a challenge for specialist diagnostic teams already encountering high volumes of referrals for individuals presenting with signature autism traits.

This trend may reflect, in part, limitations in current diagnostic taxonomies. The diagnostic criteria for neurodevelopmental disorders are vague and there is large within-condition heterogeneity, significant symptom co-occurrence, and overlap amongst neurodevelopmental disorders. The success of awareness efforts around autism in the community, including social, healthcare and educational sectors, has not been achieved to the same positive extent with respect to other neurodevelopmental conditions, enhancing the risk of misattribution of shared features to autism.

Health, disability and education systems, within which eligibility for support is based on categorical diagnosis rather than functioning, create systemic pressures towards an autism diagnosis. An autism diagnosis may be associated with supports that may not be available to those with common (e.g. borderline IQ/intellectual disability); or lesser-known (e.g. developmental language disorder or neurodevelopmental disorder associated with prenatal substance exposure) neurodevelopmental conditions; or to those with ‘subthreshold’ symptoms or challenges in multiple areas of neurodevelopment that do not ‘add up’ to any one diagnosis but are nonetheless associated with functional impairment.^3,4

These issues are exacerbated by other systemic factors that can interfere with delivery of best diagnostic practice. There are shortages of, and inadequate resourcing for expert diagnostic teams in public services, so waitlists for autism assessments are unacceptably long. ⁵ Individuals and families struggle to access co-ordinated multidisciplinary team assessments in the private sector and when they do, the cost can be prohibitive. In addition, most clinical pathways and clinical guidelines focus explicitly on the diagnostic process for one condition, and assessments are often conducted for one neurodevelopmental condition independent of another. ⁴ This is problematic for individuals with complex neurodevelopmental or psychiatric presentations, who may undergo several assessments from different specialist teams, and teams with expert skills and knowledge in one condition may not be attuned to salient features of another. ⁴ Finally, comparatively few diagnostic teams have the expertise in navigating the process of differentiating complex co-occurring concerns in the areas of neurodevelopment, disability and psychiatry simultaneously. This is especially important in the assessment of adolescents and adults where the presence of mental health concerns is the norm rather than the exception, and there is particular need to carefully consider both co-occurring and differential diagnoses ⁶ . Findings derived from different assessments conducted by sole clinicians working outside of a team environment familiar with these complexities risk resulting in multiple diagnostic labels rather than diagnostic parsimony or an integrated biopsychosocial formulation.

The National Guideline for the assessment and diagnosis of autism in Australia (the Guideline; 8) was developed to address inconsistent diagnostic practices between individual clinicians and across Australian states. ⁷ However, uptake of the Guideline in health, education and disability systems has varied, and there are systemic differences in the requirement for diagnostic rigour. Variable adherence to diagnostic guidelines and practices has the potential to create confusion for families, particularly if an autism diagnosis conducted by one clinician is accepted in one system (e.g. the National Disability Insurance Scheme) but not another (e.g. education) or in the event of receiving contradictory diagnostic opinions, such as non-consensus between an allied health clinician and treating medical specialist.

The Guideline provides a set of clear recommendations and good practice points for health professionals, some of which relate to the qualifications, training and supervision required to conduct autism diagnostic assessments. ⁸ In practice, the Guideline is often being applied by single allied health clinicians who vary widely in assessment experience. There are also no clear, consistent, or operationalised processes for maintaining high-level supervision and support for health professionals working in increasingly complex clinical circumstances and facing high service demand. Training in autism assessment is readily available, so many health professionals without previous experience in autism pursue upskilling via a brief course or training on an autism diagnostic tool. While this is a helpful start, without ongoing supervision, health professionals inexperienced in neurodevelopmental conditions may not be adequately supported to develop their clinical observational skills or consider the strengths and limitations of the available measures of autistic traits, especially when the assessment is complex and requires careful differential diagnosis.

In addition, there can be an over-reliance on the scores obtained from autism screening or diagnostic tools often without appreciating either that scores are inflated in the presence of other neurodevelopmental conditions and/or emotional or behavioural problems^9–11 or that autism diagnostic instruments are only one component of a best practice diagnostic process. ¹² Focusing only on autism screening or diagnostic tools can inadvertently reduce the emphasis placed on other key components of an autism assessment, such as a robust developmental history and consideration of collateral information from multiple perspectives, sources and contexts. Without a comprehensive approach, the diagnostic criteria may be applied as a checklist without considering the specificity of observed or described difficulties to autism, or the history, age of onset, pervasiveness or functional impact of the symptoms.

Societal and cultural context

All forms of neurodivergence, including autism, have become highly popularised in online forums. ¹³ The expansion of discourse about autism online has contributed to greater public awareness of autism and may have played a role in reducing stigma.^14,15 Access to online forums offers many potential benefits for the autistic community, such as fostering social connection and increasing opportunities for advocacy, advice and practical support. Participation in online communities also helps people gain insight into their personal experiences, which contributes to the development of a strong autistic identity built upon a culture of difference rather than deficit. ¹⁵ However, individuals and families seeking information about autism or autism diagnosis are presented with a great deal of content that is either inaccurate or overgeneralised.^13,16,17 Personal narratives are often accompanied by non-standardised lists of ‘autism traits’ or online screening tools that contain descriptions of non-specific behaviours or common human experiences as indicators of autism. Some adolescents and individuals with complex mental health histories are self-identifying as autistic based on this information because they resonate with autism concepts that have gained traction in popular discourse but lack empirical validation. In addition, high scores on online autism checklists that do not have adequate psychometric properties may be seen as definitive evidence of autism.

There are many reasons for which people may self-identify as autistic.^18–21 Individuals may derive a sense of meaning and affirmation of their subjective experiences, and may experience the self-diagnosis as a positive influence on their identity and self-understanding.^18,20 However, there is little substantive evidence supporting the validity of autism self-diagnosis, particularly when adopted by young people with complex mental health presentations. While there is emerging evidence showing similar levels of self-reported autistic traits amongst self-identified and formally diagnosed autistic adults^19,22 the groups differ on other important variables like general wellbeing and psychiatric profiles ²³ . The measurement of autistic traits in these studies is confounded by the use of tools that may not distinguish autistic features from mental health symptoms. ²⁴

Future directions

Systemic change in clinical practice is required so that individuals suspected of being autistic have timely access to high-quality diagnostic assessments. Supporting individuals who are presenting for autism diagnostic assessment requires thoughtful referral and assessment practices. When autism is suspected, it is still helpful to consider that many individuals who present with social communication difficulties, repetitive behaviours, sensory sensitivities, or difficulties managing emotions are not autistic. Before referring for an autism assessment it is important to try to understand a person holistically and parse out the non-specific difficulties shared amongst neurodevelopmental and mental health conditions from any unique characteristics of autism that may be present. It is also recommended that at the point of referral, increased attention is paid to developmental features of autism rather than focusing solely on features being described or observed exclusively in adolescence or adulthood. In addition, it is important not to prematurely foreclose on an autism diagnosis when situations are complex because this may place individuals on a pathway to inadequate or misaligned supports rather than tailored services. Diagnostic uncertainty pending further expert assessment may be an important part of widening the focus of care for the whole individual, and particularly for children and adolescents allows acknowledgement of the fluidity and flux inherent to developmental processes.

Autism diagnosis is most reliable when conducted by clinicians experienced with the full spectrum of autistic people, knowledgeable about neurotypical and neurodivergent development across the lifespan, ⁸ and familiar with common diagnostic masquerades (i.e. different presenting conditions that superficially resemble autism). Accurate autism diagnosis requires clinical acumen, the consideration of multiple possible perspectives, and an unbiased approach that is agnostic to the diagnostic outcome. Rigorous diagnostic assessments must minimally include a thorough developmental and medical history and a direct, in-person observation of the individual’s social interactions. It is best practice for gold-standard observational instruments to be used, while also recognising the limitations of these instruments and the depth and breadth of clinical experience required to accurately interpret the qualitative observations arising from these instruments, thus warranting ongoing high standards of clinical supervision. Information from multiple sources should be incorporated, the results of standardised diagnostic instruments used to inform not replace clinical judgement, and all possible differential diagnoses considered before reaching a diagnostic conclusion. A quality autism assessment should capture a person’s strengths, difficulties, functioning across developmental and life domains and support needs, and provide individualised recommendations for ongoing care.^5,8,12 Finally, systems should be configured to ensure that individuals can access timely and tailored supports regardless of their diagnostic status.