Autism Spectrum Disorders
DSM IV vs. DSM V
Triad
Neuropathology/ Neuroimaging
Treatment
Comorbidity
Epidemiology
Etiology
Theories
Diagnosis
Comorbidity
Age of onset
Other differences
DSM V: ASD --> Spectrum
DSM IV:
- Autistic Disorder
- Asperger Disorder
- Pervasive Developmental Disorder
in DSM IV: ADHD and Stereotyped Movement Disorder can't be diagnosed along with Autism
in DSM V: Symptoms don't need to be apparent before age 3
in DSM V: Social Communication and Social Interaction combined into 1 category (Category A) & they must be manifested in multiple contexts
in DSM V: alternative diagnosis if criteria are not fully met --> Social Pragmatic Communication Disorder
Level of Impairment
in DSM V: functional impairment must be present and severity levels must be specified
in DSM IV: Optional ( use of Global Assessment of Functioning)
in DSM V:
Level 3: very substantial support
Level 2: substantial support
Level 1: support
in DSM V: behavioral criteria can be met on the basis of historical report
Underconnectivity/ Computational Theory
Impaired Social Interaction/ Relationships/ skills
Impaired Communication
Additional difficulties
vary in severity between individuals and may manifest in different ways according to age
male to female ratios: ca. 2:1
for high functioning autism: 15:1
6 per 1000
highly heritable but exact cause is still unknown due to genetic complexity and phenotypic variation
advanced paternal and maternal age
environmental factors may modulate phenotypic expression e.g. teratogens
Restricted/Repetitive Interests and Activities
Sensory difficulties: hyper & hyposensitive
mood disturbances eg. anxiety, depression, aggression
motor difficulties eg. walking on tip-toes, clumsiness, poor coordination
attention difficulties eg. easily distractible
Impaired imagination
no flexible thinking
changes in routine are frightening, new/different situations are frightening
difficulties making generalizations due to focus on details
takes everything literally
lack of understanding of someone else's state of mind
difficulties with interpreting other people's face expressions & body language
unusual behaviors: being rude, shy, immature etc.
unaware of different ways to interact with staff, strangers, friends
literal understanding of language
"one way monologue"
asks repetitive questions
"can't read between the lines"
absence of desire to communicate
communications for own needs
Idiopathic ASD
majority has this type
disease with unknown cause of apparently spontaneous origin
meeting criteria for ASD but having no comorbid associated medical condition known to cause ASD
Secondary ASD
identifiable syndrome/medical disorder known to be associated with ASD
eg. known environmental agent, chromosome abnormality etc.
reduced Purkinje cells in the cerebellum
caudate abnormality --> rapid/repetitive behavior
abnormal maturation of the forebrain limbic system, including reduced neuronal size
developmental changes in cell size and number
brainstem abnormalities and neocortical malformations
abnormalities in sulcal and gyral anatomy
impaired connectivity between various cortical regions
abnormalities in functioning of mirror neuron systems--> deficits in empathy, imitation & language
Clinical Signs
Social Anxiety, ADHD, Bipolar, Depression, Down Syndrome, OCD, Motor Difficulties, Sleep problems, Tourette Syndrome
core features (triad): mostly social deficits + restricted/repetitive/stereotyped behavior
delayed/absent joint attention + delayed onset of babbling
may lack communicative intent
scripted/stereotypic eg. from favorite movies
Echolalia: "parroting"
pop up words
giant word
lack of appropriate gaze, lack of warm/joyful expressions
lack of recognition of mother's/father's voice
disregard for vocalizations eg. lack of response to name
lack of creativity and imitation
usage of common objects eg. sticks, rocks rather than store-bought toys
abnormal degree of interest
self-injurious behaviors eg. head banging, skin picking
no cure
depending on individual needs and comorbidity
rather individual therapy than group therapy
therapies to improve speech eg. verbal behavior intervention
learn to gain back empathy
virtual reality therapies
daily support by volunteers
Education how to live in society
new and still the benefits are not clear: TMS for Theory of Mind
animal- assisted therapy
triad of behavioral impairments from the article by Happe, Ronald & Plomin: social interaction, communication, repetitive interests & activities
little evidence regarding unity of those three core areas of impairment --> should be studied separately
are there separate genes contributing to the triad? YES
genetic effects are specific, acting on only one part of the triad
subclinical manifestations of all the features (especially by relatives)
abandon the search for genes "for autism" as a whole
responding to different types of treatment
Autism as neural systems disorder
frontal-posterior connectivity abnormalities --> the flow of info is impaired
increased reliance on posterior regions
Due to application of DSM V, 1/3 reduction in diagnosis (2/3 for mild forms of Autism)
reduction in the nr. of symptom domains
changes in the nr. of symptoms required for diagnosis in each of the domains
Theory of mind hypothesis of Autism/ Mindblindedness
Executive Dysfunction
Cognitive Complexity & Control Theory
Weak Central Coherence Theory
Multiple Deficit Theory
Empathizing- Systemizing Theory
The Extreme Male Brain Theory
inability to mentalise, failure to take into account others' mental states --> lack ToM
20% pass the first-order ToM task
strange stories task as more difficult
Sally Anne false-belief task
limitations: a lot of focus on the weaknesses + not addressing the non-social aspects
Domain General
Domain-specific
limitations: not addressing the social aspects, specificity, uniqueness, universality, difficulty in isolating the specific form of EF impairment, not all individuals with autism show EF problems
Enactive Mind Hypothesis as reconceptualization
Normative IQ individuals with autism can solve explicit social cognitive problems but they can't solve problems about everyday social situations
some symptoms of autism are similar to those associated with specific brain injury e.g.. to frontal lobe damage: Dysexecutive Syndrome
need for sameness (also in OCD), difficulty switching attention (also in ADHD), lack of impulse control
can account for non-social aspects of autism, acknowledges cognitive & motor characteristics
hybrid
social situations require EF because they are complex & unpredictable
EF is related to ToM, both involve higher order rule use
Domain General
not a dysfunction but rather a cognitive style
explains some social & non-social features of autism
weak/absent drive for global coherence
process things in detail-focused way--> processing constituent parts rather than the global whole
individuals with autism better in tasks: Block Design, Embedded Figures Task
Alternative Theories: Reduced Generalization: process better unique features than the common ones --> better at discrimination tasks
hybrid
limiation: maybe creates excessive amount of subcategories
autism as complex of cognitive disorders: Tom, WCC, EF are unrelated and everyone can be affected independently
in treatment: what might be effective in one domain, is maybe ineffective in the other domain
explains social and communication difficulties but also non-social
ToM is just a cognitive component of empathy
discrepancy between E & S
systemizing = drive to analyze or construct systems, noting regularities/rules, counting
not disease but rather a cognitive style that is part of a continuum
focus on weaknesses (E) and strengths (S)
clear sex differences in empathizing (females perform better) and in systemizing (males perform better)
autism as extreme of a male profile