Definition

Autism spectrum disorder (ASD) is a neuro-developmental diasbility with multi-systemic impacts. Cognitve, socio-emotional, educational and occupational functioning are often negatively affected with notable qualitative impairments in communication, reciprocal social interaction and behaviour. Specifically, the area of ASD without intellectual impairment warrants increased attention in adult mental health literature, particularly in the context of late diagnosis, that is diagnosis after childhood. Therefore, we have limited our discussion in this article to adults with ASD without intellectual impairment.

Classification

Autism was provided with an independent diagnostic category only in 1980 when the DSM-III introduced the condition ‘infantile autism’ (O’Rourke, Reference O’Rourke2016). Sets of diagnostic indicators were outlined by Gillberg & Gillberg (Reference Gillberg and Gillberg1989). However, a final cconsensus on the diagnostic criteria for Aspergers Syndrome took more than a decade later when the DSM-IV classified it as one of the pervasive developmental disorders (PDD) (American Psychiatric Association, 1994). The ICD-10 defines Aspergers as one of the ASDs or PDD, a spectrum of psychological conditions that are characterized by abnormalities of social interaction and communication causing impaired psychosocial functioning, along with restricted and repetitive interests and behaviour. In the DSM-V published in May 2013, Aspergers as a separate diagnosis was eliminated and is now classified under the umbrella term ASD.

Epidemioloigy

The Centers for Disease Control and Prevention (CDC) in America estimate that one in 68 eight-year-olds have been identified with ASD, with almost half of children identified with ASD in the average to above average intellectual ability range (Baio et al. Reference Baio, Wiggins, Christensen, Maenner, Daniels, Warren, Kurzius-Spencer, Zahorodny, Robinson, White, Durkin, Imm, Nikolaou, Yeargin-Allsopp, Lee, Harrington, Lopez, Fitzgerald, Hewitt, Pettygrove, Constantino, Vehorn, Shenouda, Hall-Lande, Van Naarden Braun and Dowling2018). Recent studies suggest that there is a much higher rate of ASD among Irish school students than previously thought. A major new report in Ireland found that 14,000 students in Irish schools have an ASD diagnosis – which equates to one in every 65 students or 1.5% of the school population (National Council Special Education, 2016). These statistics are perhaps conservative considering the increase in late diagnosis cases of ASD in adolescence and adult mental health services. Some studies suggest that the majority of ASD cases diagnosed after childhood fulfil criteria for Asperger Syndrome (Lehnhardt et al. Reference Lehnhardt, Gawronski, Volpert, Schilbach, Tepest and Vogeley2012). The earliest paper identified in current scientific literature identifies a prevalence rate of 1.9% (190 per 10 000) of ASD without intellectual impairment (White et al. Reference White, Ollendick and Bray2011). Specifically, published articles identifying the ratio of male to female prevalence rates for ASD have shown varying results such as the ratio of 15:1 (Wing & Gould, Reference Wing and Gould1979) to much lower ratios of 2.7:1 (Kočovská et al. Reference Kočovská, Biskupstø, Carina Gillberg, Ellefsen, Kampmann, Stórá, Billstedt and Gillberg2012). These lower ratios may be a sign of more improved detection rates in females in recent times.

Diagnosis after childhood

Until recently, the first time diagnosis of ASD after passing childhood and adolescence was considered rare. However, in recent years an increasing demand for diagnostic clarifications with suspected ASD in adolescence and adulthood in mental health settings is beginning to significantly challenge this view. The early identification of ASD can mitigate some of the risks associated with late diagnosis and improve the quality of life by identifying the needs and developmentally appropriate interventions, increasing access to psychosocial supports, reducing self-criticism and helping to foster a positive sense of identity (Wong et al. Reference Wong, Odom, Hume, Cox, Fettig, Kucharczyk, Brock, Plavnick, Fleury and Schultz2015).

Clinical indicators

The clinical diagnostic boundaries between ASD core symptoms and co-morbid psychiatric symptoms are often difficult to assess and to differentiate from other psychiatric conditions. In one study of 84 adolescents and young adults with ASD, a co-morbid mental health disorder was reported in 42% of the sample, a rate of up to four times that found among typically developing peers, highlighting the likelihood of overlapping disorders in this area (Moseley et al. Reference Moseley, Tonge, Brereton and Einfeld2011). For example, in adult mental health settings, there is often a significant overlap of symptoms in the area of affect, language, levels of apathy, social engagement and theory of mind (Fitzgerald, Reference Fitzgerald2012). In relation to adults, there are few studies that have been undertaken that can identify the specific psychosocial indicators of ASD in adolescence and/or adulthood on a more nuanced level. For example, using step-wise discriminant analysis, Kiyoharu & Tsuyoshi (Reference Kiyoharu and Tsuyoshi2014) identified specific psychosocial factors such as interpersonal friction, bullied experience, psychotic-like experiences, age under 32 years, school non-attendance and university educational level as clinically significant indicators of ASD. There are often factors identified that are generally associated with ASD but not clinically correlated in the context of published quantitative research using regression analysis studies/discriminate analysis studies. To date, most of the clinical focus of previous research in this area has been on younger children. However, despite a substantial amount of research still outstanding in order to clarify the above difficulty, there are a cluster of psychosocial indicators that when observed should alert the clinician to a possible case of ASD upon presenting to adult mental health services.

Using expert opinion, The National Institute for Health and Care Excellence (National Institute for Health and Clinical Excellence (NICE), 2012) guidelines suggest that the presence of at least one of the following signs or symptoms should prompt further ASD assessment in adults:

• ∙ persistent difficulty in social interaction,

• ∙ persistent difficulty in social communication and

• ∙ stereotypic (rigid and repetitive) behaviours, resistance to change (in, e.g. diet, routine or environment) or restricted interests.

  Specifically, NICE (2012) suggests there are a number of factors associated with the presence of ASD:

• ∙ problems with staying in education or finding and sustaining employment,

• ∙ difficulty in initiating or sustaining social relationships,

• ∙ history of a neurodevelopmental condition (including intellectual disability and attention deficit hyperactivity disorders (ADHD)) or a mental disorder and

• ∙ diagnosis of an eating disorder.

Assessment and diagnosis

The diagnosis of ASD is based on the most current criteria in the DSM-V or ICD-10. Ideally, diagnosis should occur within a multi-disciplinary team model assessing multiple domains across the person’s life. However, in reality ASD is a clinical diagnosis made by psychiatrists/psychologists with knowledge and experience in the area ASD (i.e. child or adult). Specifically, the following components are noted in the literature as representing international best practice in the assessment and diagnosis of individuals with a query of ASD (Department of Education and Science, 2001; British Columbia Ministry of Health Planning, 2003; National Autistic Society, 2003; Scottish Intercollegiate Guidelines Network (SIGN) Guidelines, 2016):

• ∙ review of records/history,

• ∙ medical evaluation,

• ∙ family member interview,

• ∙ clinical interview,

• ∙ direct observation,

• ∙ psychological evaluation (involving evidence-based psychometrics),

• ∙ cognitive assessment,

• ∙ adaptive functioning assessment,

• ∙ mental health assessment,

• ∙ communication assessment (speech and language),

• ∙ evaluation of social competence and functioning,

• ∙ evaluation of restrictive behaviours, interests and activities,

• ∙ assessment of family functioning,

• ∙ assessment of secondary components and

• ∙ differential diagnosis.

Co-morbidity

Adults with ASD without intellectual impairment are often particularly vulnerable to mental health problems such as anxiety disorders including social phobia and generalised anxiety disorder, depressive disorders and psychosis (Tantam & Prestwood, Reference Tantam and Prestwood1999; Russell, Reference Russell2016). There are also emerging studies identifying significantly raised prevalence rates of ASD (13 studies identified; only seven studies had IQ information – average to above average range) in eating disorder populations compared with those in healthy control participants (Bishop-Fitzpatrick et al. Reference Bishop-Fitzpatrick, Minshew and Eack2013). Adults with ASD without intellectual impairment suffer higher rates of physical and psychiatric morbidity, display a poorer ability to engage with treatment and have a lower chance of recovery compared with the general population (O’Rourke, Reference O’Rourke2016). The difficulties communicating feelings of distress can result in difficult to treat co-morbid mental health conditions particularly if clinicians and services generally have infrequent exposure to the developmental nuances of the clinical presentation.

ASD – a primary or secondary diagnosis?

Whether ASD without intellectual impairment should be designated as a ‘primary’ or ‘secondary’ diagnosis is a topic of interest in adult mental health settings. In this paper, we propose that it is important to consider ASD as a primary diagnosis when developing initial goals around psychosocial skills development, which are considered more clinically appropriate as a first line treatment as opposed to targeting the co-morbid mental health conditions (NICE, 2012). Improving a person’s functioning for example in areas such as education, employment, emotional literacy and adaptive/life skills are clinically relevant places to begin treatment and can improve the quality of life and reduce the levels of psychological distress (NICE, 2012; Taylor et al. Reference Taylor, McPheeters, Sathe, Dove, Veenstra-Vanderweele and Warren2012). In addition, a primary diagnosis of ASD can often contextualise co-morbidly high levels of social anxiety for example, which may be an appropriate response to difficulties around social engagement. Often more tailored psychosocial interventions around developing alternative ways to adapt to various different developmental life stages and the corresponding psychosocial life stressors of same are needed (e.g. managing school/college experiences, engaging in employment, relationships and independent living), as opposed to attempting to treat and rehabilitate the condition of social anxiety only. Second, addressing ASD as a primary diagnosis has meaning in terms of long-term prognosis and outcome. Not considering ASD during assessment and intervention may negatively impact treatment outcome as research continues to discover that people with ASD find it more difficult to engage with treatment and additional flexibility should be applied when a diagnosis of ASD is confirmed. It is also important to treat co-morbid mental health conditions also and adaptations to evidence-based psychological interventions are needed in this regard.

Advancing interventions and support

Current NICE guidance (2012) recommends that for people with ASD without intellectual impairment, psychosocial interventions are most appropriate for the core features of autism such as:

• ∙ social skills groups;

• ∙ life skills programmes; and

• ∙ supports for developing emotional literacy and distress tolerance.

  However, while the evidence base is limited, these approaches all have good face validity and seem to make good intuitive sense. For adults with autism and coexisting mental disorders, NICE (2012) guidelines propose offering psychosocial interventions informed by existing NICE guidance for the specific mental health disorder. A number of adaptations are suggested such as:

• ∙ increased number of sessions,

• ∙ behavioural focus,

• ∙ incorporating special interests where appropriate,

• ∙ concrete and structured approach,

• ∙ making rules clear and

• ∙ involving family members if appropriate.

  There is clearly a need for further rigorous development and evaluation of psychosocial treatments for adults with ASD. There is some evidence for Cognitive Behavioural Therapy effectiveness for common mental health conditions in adults with ASD (Binnie & Blainey, Reference Binnie and Blainey2013; Walters et al. Reference Walters, Loades and Russell2016). However, a number of areas need to be further explored in order to make specific CBT interventions more appropriate to the specific needs and abilities of individuals with ASD.

  Mental health services are now being delivered in a way that supports the recovery of mental health service-users, in line with the emergence of recovery-oriented practices. The term ‘recovery’ as used in the recovery model has been described as a process and a guiding principle which ‘... does not refer purely to the remission of clinical symptoms but is a wider concept which incorporates the person’s total adjustment to life’ (Vision For Change, 2006, p9), providing people with opportunities in the areas of personal development, building self esteem and finding meaningful roles in society. The Report of the Expert Group in Mental Health Policy makes specific recommendations regarding children with ASD and also devotes a chapter as to how mental health needs of adults with intellectual disability should be met. However, the report does not refer specifically to adults with ASD.

  It is widely acknowledged that adults with suspected ASD and co-morbid mental health problems are often not best supported through traditional mental health services and often require more tailored supports. Quite often arrangements and referrals to private healthcare facilities are made with substantial financial implications for health services. The external purchasing of specialist ASD services also limits the exposure of mental health teams to ASD, and the learning that comes from this. This creates a dearth of learning and obvious gaps in knoweldge are then further perpetuated.

  Of particular relevance to this article, the National Autism Services Review Group (2012) in Ireland noted:

• ∙ a lack of day service options for people with Asperger syndrome;

• ∙ that people transitioning to adult services often find it very difficult due to lack of formal structures in place and the lack of continuity between children and adult services;

• ∙ the importance of arranging appropriate assessment in the case of ASD in order to identify the needs and suitable interventions; and

• ∙ the lack of understanding by professionals and the public in relation to people with an ASD.

There is clearly a need for future research to examine the benefit of having a team of specialist staff within community mental health services who have received ASD training and who are supported to work with the ‘core difficulties’ of ASD. Increased awareness and a high degree of assessment and diagnostic skill to identify those with ASD should be promoted among mental health professionals. A specialist team could form a ‘hub’ for the development of expertise and specialism in ASD without intellectual impairment which could service a full community healthcare organisation, offering consultancy to other adult mental health teams on service development and training. This could be organised as a stand alone team, or integrated into generic services.

The ASD ‘hub’ would be in a position to co-ordinate the patient’s mental health recovery, psychosocial supports such as future life/career planning, further education and independent living skills through the development of care packages which would be person-centred and outcome orientated. This ‘ASD Hub’ would have named core clinical staff assigned to it from within the existing pool of MDT clinical resources (i.e. psychiatry, nursing staff, social work, occupational therapy and psychology) and would consult/engage with non-core clinical staff as clinical needs arise. The model consists of a planned route from the assessment of needs, to allocation to either group or individual intervention, with the same staff involved in the assessment, intervention and follow-up phases of treatment. The design of the ‘ASD Hub’ should fully engage clients from assessment phase right through to follow up as outlined in Fig. 1 below.

Fig. 1 Proposed process flow upon referral.

The initial clinical intake assessment is conducted in line with the adult mental health service policy and procedure. Should there be a query around ASD diagnosis or an existing diagnosis of ASD confirmed, the case is discussed at the weekly MDTM. A decision is then made to refer the case to the ASD hub. If there is no existing ASD diagnosis in place, an initial screening by the ASD Hub is undertaken which should provide a clinical rationale for conducting a full diagnostic assessment for ASD at ‘Phase 2 – Diagnosis’. This is a decision discussed at the MDTM. After diagnostic clarification, a decision is made to refer to ‘Phase 3 –Aftercare Management’ if appropriate. A case can be directly referred to ‘Phase 3 –Aftercare Management’ if there is a confirmed ASD diagnosis already in place. An assessment of need takes place which attempts to identify the most appropriate intervention for that person at that time. With this pilot model, a protocol can be followed by various team members taking into account that not all team members will have the same skills/expertise in the area of ASD. However, currently there is no evidence-based standardised approach to an ASD assessment in adults, only recommendations from a number of international bodies in the area. Therefore, a flexible team-working approach is warranted throughout the assessment process.

It is proposed that considering the significant co-morbidity of mental health disorders experienced by people with ASD, a more integrated assessment and fluid diagnostic and intervention process should be put in place in general adult mental health services. This may help patients better understand and come to terms with their own distress and would make more efficient use of scant clinical resources. Dysfunctional ASD-specific aspects of presentation should be considered and understood and more tailored intervention around these difficulties should be implemented with a view to improving the quality of life and mental health, ideally coordinated by a ‘hub’ of trained clinical staff that would have an overarching role across a number of different adult mental service teams in the region.

Financial Support

This research received no specific grant from any funding agency, commercial or not-for-profit sectors.

Ethical Standards

The authors assert that all procedures contributing to this work comply with the ethical standards of the relevant national and institutional committee on human experimentation with the Helsinki Declaration of 1975, as revised in 2008. The authors assert that ethical approval for publication of this perspective piece was not required by their local Ethics Committee.