Autism

• Autism Spectrum Disorder – History and current diagnostic criteria

  
• Autism Spectrum Disorder – History and current diagnostic criteria

  DSM-5, APA 2013

  1. Social Communication and Interaction

  2.Restricted and Repetitive behaviours
• Autism Spectrum Disorder – History and current diagnostic criteria

  
• Autism Spectrum Disorder – History and current diagnostic criteria

  
• Autism Spectrum Disorder – History and current diagnostic criteria

  
• Epidemiology

  • Incidence: Number of new cases in particular time frame in particular population
  • Prevalence Total number of cases at a particular time in particular population

  
• Gender differences

  • Studies considering the items of AQ (and their differential functioning) in adults founds no bias towards males (Grove et al., 20107)
  • Similar evidence was found for SRS and ADOS in children (Frazier & Hardan, 2017)
  • Or is it that women camouflage their symptoms? Bargiela et al., 2016
• Gender differences

  
• Gender differences

  
• Gender difference: Or is it that women camouflage their symptoms? Bargiela et al., 2016

  • Although the DSM-5 allows for an ASD diagnosis during adulthood, such a diagnosis necessitates the presence of symptoms during early development.
  • Specifically, it is clarified that such symptoms may not have fully manifested in the past due to lower social demands or it may be that these were masked by learned strategies.
• Gender differences

  
• Cognitive Theories

  • Theory of Mind
  • Executive Dysfunction Model
• Theory of Mind

  • Studies suggest that siblings promote the development of ToM but may depend on birth order (McAlister & Peterson 2013; Paine et al., 2018)
  • They are not unique to ASD
  • They cannot account for all characteristics
• Executive Dysfunction Model

  • Siblings also promote the EF skills (Cole & Mitchell, 2000)
• Aetiology

  • Early onset
  • Strong persistence
  • But a heterogeneous group
  • Kanner originally argues for a pure biological origin
  • Clinicians later argued it was learnt from cold introverted parents (Bettelheim, 1967)
  • Now, widely accepted that it is of biological origin with polygenic origin and high heritability (range from 30% and argued to exceed 80%)
  • Contribution form environmental factors suggesting an interaction
• Aetiology

  First twin study by Folstein & Rutter, 1977

  • Identical twins showed a concordance rate of 36%
  • Non-identical twins showed 0%

  Broader Autism Phenotype (see Sucksmith et al., 2011 review)

  • Spectrum of traits in family members not reaching threshold for clinical diagnosis
  • Such as social and communication difficulties, reduced ToM, reduced emotion recognition etc
  • Identical twins show a concordance rate of 82%
  • Non-identical twin show 10%
• Autism as a trait and general population

  
• Genetic findings

  • Inherited genetic mechanisms such as common and rare gene variants
  • Non inherited genetic mechanisms, de novo gene mutations

  
• Various environmental factors have been implicated, such as...

  • Hypotheroidism
  • Cocaine
  • Alcohol use
  • Valproic acids
  • Vaccines containing mercury (supported by little or no evidence; Hughes 2009), or others not containing mercury (e.g. MMR)
  • Complications during birth
  • Parental age