Identifying the Lost Generation of Adults with Autism Spectrum Conditions
Meng-Chuan Lai, and Simon Baron-Cohen (2015)
The Lancet Psychiatry 2

Introduction

Autism spectrum conditions comprise a set of neurodevelopmental syndromes. They are characterized by early-onset difficulties in social communication and usually restricted repetitive behaviour and narrow interests.

Early diagnosis tend to be made more readily in individuals with severe symptoms and current developmental difficulties. Autism spectrum conditions in people with obvious developmental delay and with more subtle difficulties tend to be recognized later. It might not be recognized until adulthood.

Challenges in making diagnosis in adults

Characteristics of autism spectrum disorder have to be present in early childhood. Interviewing informants who can provide reliable and valid information about the patient’s developmental history is essential to confirm a diagnosis. The quality of such a recall in adulthood might be inaccurate or not detailed enough. Generation effects should be taken into account.

Where informants who were present in childhood are not available, clinicians must rely on current clinical assessments, self-reported history by the patient, school or employment reports, and the observations of an information who has known the patient in adulthood.

Developmental changes complicate recognition of symptoms in adults. Developmental trajectories and outcomes of social communication are far more varied in adolescence and adulthood than in childhood. In adults, judging impairments might be arbitrary, and cultural factors and the fit of the person in his or her environment have important roles.

Under long-term social pressure to fit in, adults with autism spectrum conditions might have developed coping or camouflaging strategies.

Individuals with autism spectrum conditions have high rates of co-occurring psychiatric disorders in childhood, adolescence and adulthood. They also tend to have high rates of co-occurring medical disorders.

Diagnostic procedures

Assessment should be considered if an adult shows possible autistic features. This is at least one of the following: 1) difficulty in obtaining or sustaining employment or education 2) difficulty in initiating or sustaining social relationships 3) previous or current contact with mental health or learning disability services 4) a history of a neurodevelopmental or mental health disorder.

Diagnosis is also about how something affects a person’s life. Formal assessment should only be recommended if there is also a clinical indication.

Careful understanding of the individual’s difficulties as perceived by the patient and informants, and a clear delineation of coping strategies that have developed over time, are important to make an accurate diagnosis. Previous symptoms should be taken into account.  

Comprehensive assessment of characteristics over the lifespan is crucial to accurately identify autism spectrum conditions.

Cognitive assessments to identify individual strengths and weakness are helpful.

Lifespan developmental issues should be investigated.

Comorbid, overlapping, and differential diagnoses

Common psychiatric diagnosis include: depressive disorders, anxiety disorders, obsessive-compulsive disorder, attention deficit hyperactivity disorder and personality disorders.

Reasons for co-occurring disorders include: 1) shared pathophysiology or cause 2) consequence of living with autism spectrum conditions 3) shared overlapping symptom dimensions and possibly shared underlying mechanisms 4) overlapping diagnostic criteria.

Anxiety

Anxiety disorders are frequently seen in individuals with autism spectrum conditions.

Anxiety in individuals with autism spectrum conditions might partly interact with the need for sameness and be increased in environments that are unpredictable.

Cognitive and affective anxiety symptoms might not be clearly recognized or articulated by adults with autism spectrum conditions because coexisting alexithymia or impaired metacognition.

Detection of symptoms might need to rely on the identification of stimuli-specific or situation-specific physical and autonomic symptoms and behaviours.

Social anxiety disorder and autism spectrum conditions have similar surface-level presentation of social avoidance. Differentiation can be made by investigating the reasons for symptoms. Atypical social communication would have an early onset later in childhood, and aggravation of symptoms in teenage years in those with social anxiety disorders. Highly repetitive behaviour or unusually narrow interests are necessary core features of autism spectrum conditions but not of social anxiety disorder.

Depression and suicidal thoughts and behaviours

Identification of depression in adults with autism spectrum conditions might be challenging because of an individual’s reduced capability to recognize, articulate, and show his or her emotional states and thoughts, verbally and non-verbally.

Whether the onset of depression was overshadowed by pre-existing characteristics of autism spectrum conditions should be checked.

Depression is frequently preceded by stressful life events.

Increased frequency and intensity of suicidal thoughts and behaviours, whether associated with depression or not is a serious clinical issue that must be assessed in adults with suspected autism spectrum conditions 1) difficulties in mentalising could lead a person with an autism spectrum condition to conclude erroneously that other people would be better off without them or fail to appreciate the immense pain suicide would cause to those who love them 2) difficulties in switching attention and reduced cognitive flexibility might lead to obsessive and detailed research into methods for committing suicide 3) the literal and dichotomous thinking might lead to formation to absolute conclusions.

Obsessive-compulsive disorder

Obsessive-compulsive behaviour is an integral part of autism spectrum conditions and obsessive-compulsive disorder.

Early-onset difficulty in social communication is an important part of autism spectrum conditions but not of obsessive-compulsive disorder. Obsessive-compulsive behaviour in obsessive-compulsive disorder is often egodystonic, whereas that in autism spectrum conditions is egosyntonic and often reported to be pleasurable. Adults only with obsessive-compulsive disorder often show higher scores on measures of obsessive-compulsive behaviour than those only with autism spectrum conditions.

Psychotic and bipolar disorders

Psychosis and autism spectrum conditions are differentiated by 1) age of onset, early in life for autism spectrum conditions 2) the course, stable in autism spectrum conditions

The crucial point of differentiation is whether symptoms that seem psychotic in nature can be better understood as stemming for core features or reactive behaviours of autism spectrum conditions.

Speech in autism spectrum conditions is concrete and pedantic but logical. Speech in schizophrenia is vague, unclear and circumstantial.

Personality disorders

Schizoid and schizotypal personality disorder

Some defining features of schizoid personality disorder (social-emotional detachment and restricted affectivity) overlap with the core features of autism spectrum conditions. Features of schizotypal personality disorder include social-emotional detachment and eccentricity, which might contribute to reported co-occurrence. Differential diagnosis can be made on the basis of the repetitive, restricted, and stereotyped behaviours and interests that are specific to autism spectrum conditions.

Paranoid personality disorder

Paranoid personality disorder has no overlapping criteria with autism spectrum conditions. Differential diagnosis should consider the characteristics of autism spectrum conditions and experiences with these that can lead to increased interpersonal sensitivity and overgeneralisation of negative social experiences, which can lead to longstanding paranoid ideation.

Borderline personality disorder.

Differential diagnosis should take into account developmental history and involve a detailed assessment of non-verbal communication impairment.
Individuals with borderline personality disorder do not typically show the narrow interests, repetition, or insistence on sameness.

Antisocial personality disorder.

Autism spectrum conditions are mostly characterized by difficulties in cognitive empathy and can be associated with concurrent alexithymia.
Antisocial personality disorder and psychopathy are characterized by reactive aggression and reduce affective empathy. Cognitive empathy remains intact.

Narcissistic and histrionic personality disorder

Narcissistic personality disorder is characterized by reduced affective empathy and sympathy, but not specifically cognitive empathy.
Histrionic personality disorder is rare in combination with autism spectrum conditions. 

Obsessive-compulsive personality disorders

Characteristics defining obsessive-compulsive personality disorder overlap substantially with those for autism spectrum conditions.
It might be better to consider first whether an individual has an underlying autism spectrum condition before diagnosing obsessive-compulsive disorder.

Avoidant personality disorder.

Repeated social difficulty in autism spectrum conditions can lead to social hypersensitivity, and sensory-perceptual difficulties can increase sensitivity to stressful environments.

Dependent personality disorder

There is no overlapping criterion for dependent personality disorder and autism spectrum conditions.

Other disorders

Neurodevelopmental disorders tend to co-occur.

An important differentiation between autism spectrum conditions and attention deficit hyperactivity disorder is the nature of surface-level inattentiveness. In autism spectrum conditions in-attentiveness is characterized by slowness or difficulty in attention disengagement and switching. In attention deficit hyperactivity disorder the main characteristic is difficulty in maintaining focused attention.

Severe early social deprivation can result in quasi-autistic patterns.

A characteristic feature of neurodevelopmental disorders is the frequent presence of subthreshold symptoms, in accordance with their being on a spectrum.

To make a categorical clinical diagnosis of autism spectrum conditions, judgment should take into account the degree of distress and functional impairment and need for clinical intervention. With a dimensional view, the presence of non-clinical but strong autistic traits to broader autism phenotype is acknowledged.

Support and intervention

The diagnosis can be a relief because it provides a framework though which to explain longstanding interpersonal, social, and sensory-perceptual difficulties and make sense of feelings of difference or being on the margins. It can help self-acceptance.