Autism spectrum disorder

what is ASD

autism spectrum disorder

how did it change from DSM 4 to DSM 5

it was separate in DSM 4, as infantile autism and aspergers, and then in DSM 5 it was merged into ASD

why is it a spectrum

not because of the different reverities, but rather variation in symptoms, strengths, and support needs, and acknowledges neurodiversity

what to ASD people struggle with

• eye contact

• joint attention

• repetitive behaviors

ASD strengths

• detail focused

• strong memory

• creative in art, music and problem-solving

• honest and reliable

ASD has high cormorbidity with…

ADHD

OCD

Anxiety

in ASD adults you might see

masking skill will emerge

Theory of mind in ASD

Ecolalia

Joint attention

Shared focus on an object or event

ASD lacks joint attention

Ecolalia

repetition of others words

pronoun reversal

using he/she or own name instead of ‘I’

heritability evidence for ASD

twin studies have shown 60% concordance in monozygotic twins

100 risk genes for ASD

• Include both common SNPs and rare de novo mutations.

environmental factors

Pre-/Perinatal risk factors:

• Advanced parental age

• Air pollution and pesticide exposure

• Maternal conditions: obesity, diabetes, immune dysfunction

• Birth complications: prematurity, low birth weight, oxygen deprivation

• These do not directly cause ASD but increase risk when combined with genetic vulnerability.

Infections during pregnancy

No strong link overall, but bacterial infections during hospitalization show increased risk (Zerbo et al., 2013).

Exposure to environmental hazards

• (Botelho et al., 2024):

  • Includes air pollution, pesticides, heavy metals, alcohol, vitamin D deficiency.

  • Disruption of maternal-fetal balance may impair fetal neurodevelopment

is ASD prevalence increasing? why?

yes, from 1 in 150 to 1 in 68

why?

• broadening DSM criteria

• merging aspergers and and PDD NOS

• increased awareness and screening in schools

• Parental recognition of language delay

what is the ASD gender ratio

more males with ASD

from 3:1 to 5:1

may be due to underdiagnosis in females (masking, social adaptation)

ASD brain size

brain is larger in todlers up to the age of 4, but then growth is stunted, and is usually smaller in adults with ASD. could signify synpatic pruning

overgrown regions in ASD

Frontal, temporal, cerebellar

ASD priuning

excess synapses, but sinefficient signaling, affecting maturation and connectivity

at what age is a diagnosis of ASD considered reliable?

age of 2, but most diagnosis usually occur between the ages of 3-5

Tools for ASD screening and diagnosis

DSM-5

for children:

ADOS (observation)

ADI-R (strucutred interview)

for adults:

ADOS-G
- Adult Asperger Assessment (AAA) including AQ & EQ
- ASDI
- RAADS-R

challenges in diagnosing ASD

Females:

• mask symptoms more easily through imitation and social compensation

• are sometimes diagnosed as anxiety or mood disorders

• usually have less disruptive symptoms, so they become underrecognized

in high functioning individuals":

• may pass as quirky or introverted

• strong verbal or intellectual skills and can hide deficits in social communication

• diagnosis delayed into adolescence

ASD behavioral therapies (Applied behavioral analysis)

increase positive behaviors, reduce negative ones, teach skills

2 part of ABA:

• Discrete Trial Training (DTT): Breaks tasks into small steps; desired behaviors are rewarded

• Pivotal Response Training (PRT): Targets key “pivotal” skills (e.g., initiating communication) in natural settings

ASD speech and language therapies

• Focuses on understanding and expressing language (spoken or signed).

• Goal: Early communication skills, using symbols or speech.

ASD occupational therapy

sensory integration therapy:

• Improves response to sensory input.

• Develops fine motor skills, self-regulation, and social participation

ASD social relational therapies

• DIR/Floortime: Builds emotional connection through child-led play.

• RDI (Relationship Development Intervention):

• Social stories and social skills groups

ASD pharmacological treatments

not curative but help reduce symptoms usually tied to anxiety, sleep problems, seizures

psychological interventions

Congitive behavioral therapy: Addresses anxiety, mood, and emotional understanding.

Differences between ASD therapies in adults and children

methodology (ABA) is almost the same but the goals are different:

children: focused on social interaction and communication

adults: focus on independent living skills (cooking, cleaning, budgeting)

Vocational rehabilitation

Social skills training is most effective when…

done in childhood

neuroplasticity is the highest in…

the first 3 years

Criticisms of ABA therapy

• May be too rigid or intense for children

• Seen as overly focused on compliance, not individuality

• Critics argue it seeks to "eliminate" neurodivergent traits

• ABA may pathologize differences rather than support neurodiversity

Old DSM 4 criteria

Pervasive developmental disorders:

• Autistic disorder

• Asperger syndrome (high functioning autism)

• childhood disintegrative disorder

• PDD NOS

ASD prevalence

1 in 100

ASD brain

• Children with ASD (especially those with a family history) show:

  • Faster early brain growth

  • Increased surface area expansion

• These changes are detectable before age 2, reinforcing the importance of early screening and genetic risk factors.

• Cortical thickness changes are less distinct, likely part of typical development.