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Autism and Co-occurring conditions - Coggle Diagram
Autism and Co-occurring conditions
Autism recap
Social communication skills -
Building friendships
Reciprocity
Initiating and maintaining
Emotions
Poorly integrated verbal and nonverbal communication
Eye contact
Gestures
Facial expressions
Repetitive behaviour and restricted interests -
Repetitive motor movements
Insistence on sameness
Restrictive interests
Repetitive speech
Compulsive behaviours
Present from early develop, clinically significant impact on day to day life and across environments
Cannot be better explained by the presence of intellectual disability
Co-occurrence / comorbidity:
Refers to the co-occurrence of two separate conditions, a co-occurence than is higher than would be expected to change (Feinstein, 1970; Banaschewski et al, 2007)
-> Comorbidity is the rule, not the exception (Gilger & Kaplan, 2001)
-> This is due to diagnostic systems, overlapping criteria, heterogeneity and common underlying aetiology
Embrace Neurodiversity comorbidity statistics -
Between 40-70% of children with ASC / Autism have ADHD as well
Around 6-22% of children with Tourette’s have ASD as well
More than 4 in 5 people with ASC and Autism have DCD as well
Around 75% of children with ASC have DLD
Diagnostic overshadowing -
Tendency to attribute all problems to a primary diagnosis, thereby leaving other co-existing conditions undiagnosed
Examples - Moss & Howlin, 2009 & Masocowitz et al, 2017
Autism and intellectual disability
Level of ID - ICD-10 classification - IQ scores indicate:
Mild: 50-70
Moderate: 35-49
Severe: 20-34
Profound: < 20
IQ distribution in autism (Muglia et al, 2018)
-> Generally forms a normal distribution, but those with Aspergers tend to score higher than those with AD (around 40% of autistic individuals have ID; differential impact due to labels and the relationship between IQ and autism)
-> PDD-NOS individuals fall around the average
-> Strong heterogeneity
Issues as a result - Sensitivity of assessments in SID (Thurm et al, 2019):
Developmental milestones - prior to age of 18 months, it is difficult to assess ascertainment of specific skills e.g. spoken language develops at this age
Assessments typically developed with samples of autistic individuals without ID
Studies demonstrate lack of sensitivity and specificity when used in individuals with ID, particularly severe and profound
Reliance on clinical expertise
Autism is significantly more likely to occur in those with ID compared to a typically developing population
Increased prevalence of autism in ID, and this increases with the severity - severe and profound ID makes having autism more likely, and separating these diagnoses becomes harder at more severe levels
Autism in individuals with ID (La Malfa et al, 2004) - in this sample, around 39.2% had ID at the following splits
-> Mild - 8.3% of those with autism
-> Moderate - 24.3% of those with autism
-> Severe - 37.1% of those with autism
-> Profound - 59.6% of those with autism
-> Harder to distinguish what characteristics are the ID or autism
One of the diagnostic criteria for autism is that it is not better explained by ID - attempted to disentangle the diagnoses, but there is actually more referrals for autistic individuals without ID
More individuals without ID being diagnosed with autism, but the proportion of having both is becoming smaller because disentangling them has made it harder
This parameter has also created more caution around ID diagnosis
Autism in genetic syndromes associated with ID - Richards et al, 2015:
Genetic syndromes associated with ID
-> Neurodevelopmental disorders with a known genetic cause
-> Genetic syndromes account for approximately ⅓ of all occurrences of intellectual disability
--> 50% severe intellectual disability
--> 13% mild/moderate intellectual disability
-> Heterogeneity - different genetic syndromes tend to have their own unique autism profile
-> Atypical presentations which shows the heterogeneous presentation
Development trajectory of autism characteristics -
SCQ (autism) score changes - FXS and CdLS have opposite development; scores start high in FXS and decrease into adulthood, whereas CdLS scores start low and increase with age
Differences in presentation and trajectory of these characteristics, and the severity of these over the lifetime - well replicated effect
Challenges for diagnosis and assessment:
Atypical presentations e.g. autism in genetic syndromes or anxiety in autistic children
Validity of assessment e.g. sensitivity of autism assessments with co-occurring ID
Agreement - SCQ / ADOS
-> Agreement of 67%, with ADOS deciding 67% meet criteria and SCQ has 62%
-> ADOS has 19% of its diagnoses not shared, with SCQ having 14%
-> Agreed on 48% of diagnosis with ASD and the 19% that did not have ASD
-> Issue may be with those who might have it, not those who definitely do not
Diagnostic overshadowing
Delay in autism diagnosis, requirement for clinical input to support diagnosis in the genetic syndrome sphere, and this is not always readily available
-Impact at an individual level - cost, understanding, access, support
Autism in genetic syndromes;
19 years CdLS
Autism characteristics from a very young age
-Transition to college
Poor mental health
Poor sleep
Withdrawal from college
Autism and ADHD
Inattention -
Careless mistakes
Difficulty sustaining attention
Does not seem to listen
Does not follow instructions
Difficulty organising
Avoidance of tasks that require sustained mental effort
Often loses things
Easily distracted
Forgetful in daily activities
Hyperactivity / impulsivity -
Fidgets / squirms
Often leaves seat
Often runs / climbs excessively
Difficulty playing quietly
On the go
Often talks excessively
Often blurts out answers
Difficulty awaiting turn
Often interrupts / intrudes
Autism and ADHD:
Boys are more than twice as likely as girls to be diagnosed with ADHD (Bauermister et al, 2007)
50-70% of genetic factors overlap
Similar deficits in executive function, social-cognition and motor speed
Overlap of core symptomatology - AuDHD - co-occurrence term as the diagnosis of both has become so common
Nilmeijer et al, 2008 & Romelse et al, 2011:
Autism core features present in ADHD -
-> Social communication - peer relationships, poor social skills, language delay and difficulty understanding others thoughts and feelings - different reasons but similar presentations
-> Repetitive behaviour - stereotypic behaviour and sensory sensitivity
ADHD core features present in autism -
-> Attention problems, emotion regulation problems and hyperactivity / impulsivity
-> Similarly, some subtle differences in the nature of these that perhaps are difficult to identify on general diagnostic assessments - require more refined or more detailed approach
Autism and ADHD - phenotype-genotype correlation:
Phenotype and genotype correlations between the core domains of ASD and ADHD
Phenotypically -
-> Inattention is correlated with both ASD domains
-> Hyperactivity is more strongly correlated with repetitive / restrictive behaviours
Strongest genetic correlation between hyperactivity and repetitive/restrictive interests (Ghiradi et al, 2018)
This also suggests that this diagnosis overlap comes from domain-specific diagnoses and symptoms
Challenges for diagnosis and assessment -
Historically ADHD and ASD were mutually exclusive
Overlapping characteristics - are the different diagnostic categories useful
-> Targeted intervention and support
Teasing apart common symptoms and identifying the primary symptoms
Refined behavioural evaluation required
Differences masked by clinical diagnostic assessment tools
Autism and mental health
Almost 70% of autistic individuals experience at least one psychiatric disorder (Hossain et al, 2020)
Nearly 40% have two or more (DeFilippis, 2018)
Psychiatric comorbidities are the main reasons for referral to outpatient clinics and admissions to hospital among autistic individuals (Saleh & Adel, 2019)
Associated mental health conditions (Hossain et al, 2020)
-> ADHD (25.7-65%)
-> Anxiety (1.47%-54%)
-> Schizophrenia (4-67%)
-> Mood disorders (6-21.4%)
-> Conduct disorder (12-48%)
-> Depression (2.5-47.1%)
-> OCD (9-22%)
-> Other - ED, PTSD, substance abuse
--> Driven by focus on weight numbers and other mechanisms that are different to typical causes
Mental health outcomes in adults with autism -
Longitudinal follow up of some of the first children diagnosed with autism in the UK (1950-1979)
N = 58 participants (48 males, 10 females)
Non-verbal IQ > 70
Average time between diagnosis and follow up - 37 years
The Family History Schedule - occurrence of major mental health difficulties since the age of 16 years (Moss et al, 2015)
-> OCD, depression (episodic and chronic), bipolar disorder, anxiety disorder and other (schizophrenia, mania and paranoia)
-> Most significant finding - depression was the most reported, with anxiety and OCD also being commonly reported
-> Self-reports were more likely to identify mental health difficulties rather than their informers and carers - experience of challenges may be quite different to others perception of it
Challenges of diagnostic and assessment: Moscowitz et al, 2017
Traditional methods of assessment of anxiety require self-report
-> High proportion of non-verbal individuals and those who are verbal may experience difficulty in describing their thoughts and feelings
Reliance on self report
-> Parents / carers may not be aware of or correctly interpret their child’s thoughts, feelings and behaviours
-> Association between autism and ID compounds this
Atypical presentation
-> Expression of fear or anxiety may be through specific behavioural responses
-> Content / focus of anxiety may be different to that identified in NT children
Overlap in core characteristics - e.g. social avoidance
Masking and camouflaging:
Draws on concept of compensation from neurology i.e. alternative / adaptive neural processing following brain injury
Some autistic individuals can, in certain contexts, appear NT (Livingston et al, 2020)
70% of autistic adult participants reported that they consistently camouflage (Cage & Troxell-Whitman, 2019; Mandy, 2019
Social camouflaging in autism - is it time to lose the mask?
Many autistic people feel obliged to pretend not to be autistic - considerable effort is put in to modify behaviours to the NT norm
Compensation, masking, social camouflaging
Strategies are diverse, and some are simple
-> Some are more complex, developed by carefully, consciously and protracted learning
70% of autistic individuals report that they do this consistently (Cage & Troxell-Whitman, 2019)
Camouflaging is seen as a typical response, or an obligation, rather than a choice, motivated by wanting to avoid ostracism, threat and alienation
Benefits - achieve goals, such as education and jobs, and establish relationships with NT people
Consequences -
Hide difficulties, preventing diagnosis as they are not showing their need for help (Bargiela et al, 2016)
-> Important role particularly in diagnosing women (Hull et al, 2019)
Mental health impacts - higher rates of anxiety and depression (Cage & Troxell-Whitman, 2019)
-> Cassidy et al, 2018 - linked to higher suicidality
-> Because it is exhausting and stressful, there is a causal mechanism with autism and anxiety (Livingston et al, 2019) due to autistic burnout
-> Erosion of self identity (Hull et al, 2017) and misunderstanding of needs can also result in mental health issues (Bargiela et al, 2016)
-> Can mediate the relationship between social stressors and subsequent anxiety and depression
-> Also suggested that inhospitable environments mediate autism and mental health, and future research could investigate this
Wider lessons -
It is a creative, useful response to difficulties despite its consequences - attempts that autistic people make to adapt are more stressful than beneficial, and environments should adapt to them
Autism intervention should focus on the individual fitting better with the environment, done with changing only the environment (Mandy et al, 2016)
Needs led or label led
Those who get a diagnosis and receive services are better off than those with no diagnosis but impairment
Meeting a threshold can be the determiner of treatment - those just below the threshold may still not get help despite the need for it in a label led approach
Positives of a label led approach -
->Given access to support networks
-> A ticket to get past gatekeepers and access services
-> Helps understand self - different, not ‘stupid’, ‘broken’, ‘weird’ or ‘wrong’
Negatives of a label led approach -
Fixed view of self
Stigma from others
Fear a label becomes a self-fulfilling prophecy
Autism and comorbidities
https://mts.intechopen.com/storage/books/8430/authors_book/authors_book.pdf#page=34.08
Complex ND disorder that displays brain network abnormalities
Decreased brain connectivity or functional synchronisation between frontal and more posterior cortical regions (fMRI)
Dynamic brain activity (EEG) has revealed local overconnectivity and long-range underconnectivity - disrupted connectivity would involve the corpus callousum along with axonal and synaptic connectivity within hemispheres
Abnormality in facial perception - unable to understand facial expressions and ignore looking at faces
-> Covert attention - visually attentive and perceptive, but atypically, as they have more activation in fusiform gyrus with averted than direct gaze
-> Show typical activation with familiar faces - reduced connectivity in brain areas has been implicated in atypical facial perception
-> Social motivation and cognition both rely on facial processing, thus issues with this lead to these social executive function impairments
Body - repetitive movements -
Strong and complex genetic basis - alterations in overall gray and white matter volume
Early brain overgrowth is one of the most replicated findings
-> As a result, moved toward connectivity disorder models over lesion models
-> Minshew & Williams - intra-hemispheric connectivity is mainly involved in the disorder
-> Long range cortico-cortical functional and structural pathways display weaker connectivity in people with ASD, but less evidence for overconnectivity (Vissers et al,)
-> EEG studies have however supported long range underconnectivity
-> Harden et al - reduced corpus callosum volume has been linked to social deficits and repetitive behaviour
-> Communication abilities - abilities are disrupted due to deviant central nervous system development, which includes long range underconnectivity and local overconnectivity
Comorbidity with DCD
Autistic children have reported deficits in ability to produce meaningful and meaningless gestures on command, imitate demonstrated gestures and initiate gestures of imaginary tool use
Impairments with praxis therefore contribute to primary features of impaired social interaction and communication skills
Co-occurrence with childhood apraxia of speech - in both verbal and nonverbal autistic children, it comes through in defective vowel production, prosody and difficulty in imitation of speech sounds
-> Augments problem with social and language delay and presents a large obstacle in their speech development
-> However, this comorbidity is still vague (63.6% comorbidity in a recent study)
Sensory processing disorders -
-When sensory processing is dysfunctional, the individual’s ability to cope with the demands of the environment is disrupted
Suarez - hierarchical model
-> Sensory-based motor disorder - poor motor planning, postural inability from improper processing of information from senses
-> Sensory discrimination disorder - inability to perceive differences and similarities in data received from the senses which can make reading very challenging
-> Sensory modulation disorder - impairment in intensity and nature of behaviour in response to sensory information - most common in autism, divided into sensory hyporesponsive, hyperresponsive and sensory seekers
However, autistic children show a mixture of symptoms in each category, and some research has shown positive associations between hyporeactivity and social communication symptom severity, whereas hyperreactivity has been linked to negative family life and socially adaptive behaviours of school children
Gabriels et al - suggested presence of a subgroup with restricted repetitive behaviour and multiple abnormal sensory responses due to significant relationship between both
->Reactions to sensory stimuli are in the DSM under the repetitive behaviours symptom category