Series
Autism 4
Evidence-based support for autistic people across the
lifespan: maximising potential, minimising barriers, and
optimising the person–environment fit
Meng-Chuan Lai, Evdokia Anagnostou, Max Wiznitzer, Carrie Allison, Simon Baron-Cohen
Lancet Neurol 2020; 19: 434–51 Autism is both a medical condition that gives rise to disability and an example of human variation that is characterised
Published Online by neurological and cognitive differences. The goal of evidence-based intervention and support is to alleviate distress,
March 3, 2020 improve adaptation, and promote wellbeing. Support should be collaborative, with autistic individuals, families, and
https://doi.org/10.1016/
service providers taking a shared decision-making approach to maximise the individual’s potential, minimise barriers,
S1474-4422(20)30034-X
and optimise the person–environment fit. Comprehensive, naturalistic early intervention with active caregiver
See Comment page 374
involvement can facilitate early social communication, adaptive functioning, and cognitive development; targeted
This is the fourth in a Series of
four papers about autism
intervention can help to enhance social skills and aspects of cognition. Augmentative and alternative communication
interventions show preliminary evidence of benefit in minimising communication barriers. Co-occurring health
Margaret and Wallace McCain
Centre for Child, Youth & issues, such as epilepsy and other neurodevelopmental disorders, sleep problems, and mental health challenges,
Family Mental Health, Azrieli should be treated in a timely fashion. The creation of autism-friendly contexts is best achieved by supporting families,
Adult Neurodevelopmental reducing stigma, enhancing peer understanding, promoting inclusion in education, the community, and at work, and
Centre, and Campbell Family
Mental Health Research
through advocacy.
Institute, Centre for Addiction
and Mental Health, Toronto, Introduction of autism—encompassing both disabilities (resulting from
ON, Canada (M-C Lai MD); Autism spectrum disorder (ASD) or autism spectrum atypical neurobiology) and differences (a neurodivergent
Centre for Brain and Mental
Health and Department of
conditions (ASC)1,2—referred to here as autism—are early- profile of strengths and weaknesses)—is key to support-
Psychiatry, The Hospital for emerging neurodevelopmental conditions with strong ing autistic people (appendix p 3). In addition to the
Sick Children, Toronto, ON, genetic aetiologies,3 shaped by gene–environment inter- core characteristics of autism, many co-occurring health
Canada (M-C Lai); Department play.4 Changing diagnostic criteria,5 improved recognition conditions—such as other neurodevelopmental disorders,
of Psychiatry, Faculty
of Medicine, University of
of autism and its heterogeneous nature,6 and increased epilepsy, sleep problems, and mental health challenges—
Toronto, Toronto, ON, Canada awareness in society7 mean that autism—formerly are prevalent in autistic individuals.1,2 Care should be
(M-C Lai); Department of regarded as rare—is now deemed to be a relatively com- multidisciplinary and collaborative, with shared decision
Psychiatry, National Taiwan mon condition. Globally, approximately 1% of the popula- making and action planning,13 based on an in-depth
University Hospital and College
of Medicine, Taipei, Taiwan
tion has a formal diagnosis.8 In high-income countries, the understanding of the autistic individual’s and the family’s
(M-C Lai); Autism Research prevalence is close to 1·5%,9 with a male-to-female ratio lived experiences.
Centre, Department of of about 3:1.10 Characteristics associated with autism In this Series paper, we aim to bring to the attention
Psychiatry, University fall along a spectrum in the general population across of health professionals from a variety of disciplines—
of Cambridge, Cambridge, UK
(M-C Lai, C Allison PhD,
dimensions of social communication, repetitive and including general practice, psychiatry, psychology, develop-
Prof S Baron-Cohen PhD); stereotyped behaviours, sensory sensitivity, and other non- mental paediatrics, and neurology—the best available
Bloorview Research Institute, clinical and cognitive features (eg, attention to detail).5 evidence on existing interventions and support, and to
Holland Bloorview Kids
Autistic traits are particularly common in first-degree and highlight opportunities for progress in improving the
Rehabilitation Hospital,
Toronto, ON, Canada second-degree relatives of people with an autism diagnosis, health and wellbeing of autistic people. Despite decades of
(Prof E Anagnostou MD); reflecting shared genetic background.11 Both clinical empirical research, evidence for treatment efficacy—even
Department of Paediatrics, autism and dimensional traits are associated with the for some commonly used interventions14—is often weak or
Faculty of Medicine, University
additive effect of common and de novo rare genetic vari- scarce. Nevertheless, the evidence base is improving,
of Toronto, Toronto, ON,
Canada (Prof E Anagnostou); ations,3,12 although the exact causal roles of associated owing to more regular use of randomised controlled trial
Division of Pediatric variants remain unclear. (RCT) designs, increasing focus on effectiveness and
Neurology, Rainbow Babies Autism affects an individual’s development and ability to implementation,14–16 and the incorporation of participatory
and Children’s Hospital,
adapt across the lifespan (appendix p 1). Autistic people, research.17 We propose a framework, based on current
Cleveland, OH, USA
(Prof M Wiznitzer MD); School even those who are diagnosed early in life, have variable interventions, that comprises three pillars of evidence-
of Medicine, Case Western long-term outcomes.1 Many face everyday challenges in based care and support across the lifespan: (1) maximising
Reserve University, adaptive functioning throughout childhood, adolescence, the potential of the individual by facilitating development
Cleveland, OH, USA
and adulthood, including difficulties with independent and building skills; (2) minimising barriers that impede
(Prof M Wiznitzer);
and Cambridgeshire and living, education, employment, sexual and romantic rela- the individual’s development and adaptation; and (3) opti-
Peterborough National Health tionships, community involvement, health, and quality of mising the person–environment fit by making reason-
Service Foundation Trust, life.1,2 An approach that acknowledges the dual nature able environmental adjustments to enhance adaptation
434 www.thelancet.com/neurology Vol 19 May 2020
, Series
Cambridge, UK
Maximising potential Minimising barriers Optimising the person–environment fit (Prof S Baron-Cohen)
Correspondence to:
Aim Aim Aim
To select interventions appropriate for the age and To identify and minimise barriers that impede the To address socio-ecological factors and make Dr Meng-Chuan Lai, Centre for
developmental level of the individual and the individual’s development and adaptation reasonable environmental adjustments to create Addiction and Mental Health,
socio-ecological context to facilitate development autism-friendly contexts and enhance adaptation 80 Workman Way,
and build skills Approaches Toronto, ON M6J 1H4, Canada
• Augmentative and alternative communication Approaches mengchuan.lai@utoronto.ca
Approaches systems (eg, PECS and assistive technology) to • Adjustments to enhance environmental
See Online for appendix
• Early intervention involving caregivers (eg, NDBI or reduce communication difficulties predictability and the autistic individual’s sense of
EIBI in early childhood) to improve social • Intervention to address sensory issues and control, while allowing for the uncertainty and
communication, developmental outcomes, and unwanted RRBI (eg, specific sensory-focused flexibility necessary in educational, work, and
adaptive behaviour interventions and modified CBT) community environments
• Targeted intervention (eg, social skills training) to • Regular screening, assessment, and timely • Support for caregivers and family to improve
improve a pivotal set of adaptive skills environmental adjustment alongside psychosocial, problem-solving and stress coping, and to reduce
• Individualised educational support based on the behavioural, and medical intervention to treat misunderstanding and enhance communication
person’s strengths and needs to develop knowledge co-occurring physical and mental health and relationships within the family
and skills through school experience conditions, coordinated by primary care physicians • Education and awareness building to increase
• Pharmacological intervention (candidates currently and supported by multidisciplinary specialists understanding of autism, reduce stigma, and
in development but not yet approved by regulatory improve autistic individuals’ wellbeing in the peer
jurisdictions) to improve social-communication context, community, and society
adaptive functioning • Vocational support
Figure 1: A framework for the care and support of autistic people across the lifespan
The proposed framework comprises three pillars based on available evidence-based interventions and promising new approaches to intervention and support.
The overall goals are to enhance autistic people’s adaptation and wellbeing and to reduce distress and disability. The framework could be adapted as novel
evidence-based interventions become available. Complementary and alternative treatments with an acceptable safety profile (panel 4) could be incorporated on the
basis of individual needs as the evidence base grows. CBT=cognitive behavioural therapy. EIBI=early intensive behavioural intervention. NDBI=naturalistic
developmental behavioural intervention. PECS=Picture Exchange Communication System. RRBI=restricted, repetitive behaviour and interests.
(figure 1). Finally, we identify knowledge gaps and outline Polarising the medical and neurodiversity views, as if they
future directions for research. Although this Series paper were mutually exclusive, will hold back progress both
focuses on autism, we hope that it provides a frame- scientifically and clinically. The duality view (appendix p 3)
work for the support of people with other developmental creates a common ground for medical, psychological,
disabilities. social, and environmental intervention and support
for autistic people, with the aim of alleviating distress
Meeting the needs of autistic people and their and improving adaptive functioning and quality of life
families (panel 1).19–23
The dimensional nature of autistic traits makes it chal- Respecting the autistic individual’s right to dignity
lenging to draw a clear diagnostic line, and this is likely to and self-determination, while acknowledging disabilities,
remain true even when other diagnostic biomarkers are requires that as a society we create autism-friendly envir-
available.5 From a clinical perspective, a diagnosis is made onments (similar to expectations for other developmental
on the basis of the intensity of autistic characteristics and and physical disabilities). Support should be dynamic
the extent to which these characteristics cause impairment across the lifespan, as adaptation issues differ in childhood
of adaptive functioning. This means that two people with (eg, educational) versus adulthood (eg, residential and
the same level of autistic traits or the same underlying occupational). Transition to adulthood can be challenging
biomarkers can have different needs: one might benefit and evidence-based support is insufficient at present.24
from a diagnosis because the traits affect their adaptive Moreover, obtaining services and support for autistic
functioning, whereas the other might find that autistic adults, with or without communication or intellectual
traits do not impede their daily functioning and a diag- disabilities, has been particularly difficult owing to the
nosis is not warranted. From a developmental perspective,18 structure of healthcare service systems and insufficient
adaptation is the product of the transaction between an funding,25 signalling a pressing need for systems-level
individual and their environmental contexts; a clinical improvement. Shared decision making among autistic
diagnosis of autism is required only if there is a poor individuals, families, and service providers should be at
person–environment fit that results in impaired adaptive the heart of multidisciplinary, collaborative care (figure 2),13
functioning.2,4 whether addressing the core disabilities of autism or co-
On the one hand, autism is a condition that entails occurring conditions. The lived experiences of autistic
disability, which requires treatment or intervention (the individuals and their families are central to understand-
medical view). On the other hand, autism is a form ing support needs, as shown by recent priority-setting
of human variation, with a profile of strengths, differ- initiatives (appendix p 5).26–28
ences, weaknesses, and disabilities that results in a lived International standards of evidence within medicine and
experience that might fit comfortably or uncomfortably health care have not been applied sufficiently, despite
with a particular environment (the neurodiversity view). decades of empirical research on intervention and support
www.thelancet.com/neurology Vol 19 May 2020 435
, Series
could be adapted as understanding of the biological
Panel 1: Principles for intervention and support in current substrates of autism and co-occurring conditions pro-
clinical guidelines and recommendations gresses and new evidence-based interventions emerge
Current clinical practice guidelines and recommendations (figure 1). Early diagnosis is the starting point for high-
developed by governmental or professional organisations quality care and support (panel 2),5 and key to successful
rely on systematic reviews and expert panel discussions.19–22 outcomes for some interventions, but the proposed
They commonly take a holistic approach and emphasise that framework applies to autistic people across the lifespan.
service providers should do the following: (1) receive training The characteristics and disabilities of people diagnosed
in autism awareness and management, and ensure that the later in life might seem to be subtle on the surface, but
autistic individual and their family have access to health and these autistic individuals still experience substantial
social care services; (2) support the individual and family challenges in adaptive functioning and threats to well-
to obtain behavioural, educational, and psychosocial being that need to be addressed (panel 3).2 A summary
interventions (for children and adolescents) or vocational of current evidence for complementary and alternative
support (for adults), adjusted to the person’s developmental treatments is provided in panel 4.34–53
level and individual needs to improve life skills, while
acknowledging the level of evidence to date; (3) consider Maximising potential
psychosocial, behavioural, and pharmacological treatment Early intervention
for co-existing challenges such as anxiety, irritability, Early intervention generally refers to therapy for children
hyperactivity-inattention, or sleep disturbances, based on aged 6 years or younger. Early intensive behavioural inter-
knowledge derived from the autistic population when vention (EIBI) has been widely used since the 1960s. The
available, or from the non-autistic population; (4) facilitate approach is based on applied behaviour analysis (ABA)
adjustment of the social and physical environment and principles and characterised by intensive (20–40 h per
process of care to meet individual needs; (5) support families week) and long-term (1–4 years) intervention, use of
and carers; (6) maintain an active role in long-term support, discrete trial training, one-to-one delivery of teaching
including life transition issues (eg, transition to adult services); by an adult therapist, and comprehensive targets for
and (7) improve the involvement of autistic individuals and improvements in skills and changes in behaviour. The
their families in planning of their own support. However, latest Cochrane review,54 based on a small number of
guidelines also vary in their recommendations regarding how trials—one RCT and four non-randomised controlled
social factors affect the diagnostic process, contexts of trials (a total of 219 children)—with a low quality of
assessment, and interpretation of needs; further work is evidence, suggests that EIBI can improve autistic
needed to improve clarity and consistency.23 children’s adaptive behaviour (mean differences [MD] on
the Vineland Adaptive Behaviour Scale [VABS] composite,
9·58) and developmental outcomes, including intelli-
for autism, as demonstrated by the latest rigorously gence quotient (MD 15·44), expressive language (stand-
conducted reviews.14,29,30 The efficacy research literature ardised mean differences [SMD] 0·51), and receptive
is composed of more single-case designs than group language (SMD 0·55); however, there was no significant
designs of RCTs or quasi-experimental trials.31 Most inter- effect of EIBI on core autism characteristics.
vention trials are small in size—with a median sample size A US Agency for Healthcare Research and Quality
of 36, according to a 2018 survey32—and have a selec- (AHRQ) report55 showed that models are moving away
tion bias towards including a disproportionately small from structured (traditional EIBI) towards naturalistic
percentage of individuals with intellectual disability.33 Few approaches, under the umbrella term of naturalistic dev-
trials are able to show long-term benefits or generalisation elopmental behavioural intervention (NDBI).56 Stimula-
of effects to wider contexts.14 The result is generally weak ted by research in developmental science and the
or insufficient evidence for treatment efficacy, even for cognitive science of autism, the development of NDBI
some commonly used early interventions and social skills models aims to reduce the discrepancy between highly
groups.14 It is troubling that many commercial inter- structured ABA approaches and principles of child
ventions (ranging from behavioural to medical approaches) development (appendix p 8). However, NDBI is a broad
are widely advertised, actively promoted, and used by category and not all models have been tested by rigorous
autistic people across the globe, but not supported RCTs or have equal levels of evidence, so positive findings
by rigorous evidence. The evidence base for intervention from one NDBI model cannot be taken as evidence
and support in autism should not be exempt from the supporting another.
standards widely accepted in other fields of medicine. Evolving models recognise the importance of involv-
An urgent need exists to improve the overall quality of ing and training caregivers (panel 2). Parents act as
evidence across all intervention and support approaches. co-therapists in several EIBI models, and caregiver
We propose a framework for care and support, based on involvement is core to NDBI given the emphasis on
the evidence available for existing psychosocial, behavi- naturalistic social interaction and ecological validity (ie,
oural, biological, and environmental interventions, that representative of or generalisable to real-life situations).
436 www.thelancet.com/neurology Vol 19 May 2020
