AUTISM
WHAT IS AUTISM?
Lorna Wing’s triad of impairments
- Difficulties in social interaction
- Difficulties in communication
- Lack of imagination / repetitive interests
Heterogenous - no two people are the same
Classical autism, Aspergers syndrome / High Functioning Autism (HFA), Pervasive Developmental
Disorder Not Otherwise Specified (PDD-NOS)
PDD-NOS :not sure where else to put them
PDD-NOS: absence of repetitive behaviours or communication deficits
Concurrent learning difficulties and epilepsy common in autism
Moldin (2006): social impairments are what characterise autism from other developmental disorders
The autistic spectrum contains a wide range of intellectual ability
Fombonne (1999):
- 19% no intellectual impairments
- 42% severe learning difficulties
DIAGNOSIS
Not commonly diagnosed before 2 years
GP sees child - can use basic checklists
- CHAT (Checklist for Autism in Toddlers)
- CARS (Childhood Autism Rating Scale)
Conclusive diagnosis from:
- Clinical observation - does child meet criteria? (DSM-IV)
- Diagnostic interviews: ADOS / ADI / DISCO
ADOS:
- Autism Diagnostic Observation Schedule
- 4 levels depending on verbal abilities of participant
- Children - games, books etc and observe behaviour
- Adults - interviews plus some puzzles, requires a lot of training
- US formalised procedure
ADI:
- Autism Diagnostic Interview
- For parents
- Structured interview
- Requires some training
- Not so useful for adults
DISCO
- Diagnostic interview for social and communicative disorders (Wing et al., 2002)
- Detailed - which bits of social interaction does this child have difficulty with - what do we need to
target?
DSM-V (in revision) - shorter and simpler list but may still be revised
No Aspergers!
, Combine social and communication symptoms
1. Clinically significant, persistent deficits in social communication and interactions, as manifest by all of
the following:
a) Marked deficits in nonverbal and verbal communication used for social interaction
b) Lack of social reciprocity;
c) Failure to develop and maintain peer relationships appropriate to developmental level
2. Restricted, repetitive patterns of behaviour, interests, and activities, as manifested by at least TWO of
the following:
a) Stereotyped motor or verbal behaviors, or unusual sensory behaviours
b) Excessive adherence to routines and ritualized patterns of behaviour
c) Restricted, fixated interests
3. Symptoms must be present in early childhood (but may not become fully manifest until social
demands exceed limited capacities)
WHAT KIND OF CHILDREN HAVE AUTISM?
Lingham et al. (2003)
- 567 children with ASD in NE London
- 85% male
- 50% typical autism
- But missing people who may have ASD but not diagnosed
- Autism prevalence increased until 1992 then plateued - this leveling off, together with the decreased
age at diagnosis suggests factors like increased recognition, greater willingness to diagnose, better
recording and awareness
HOW MANY CHILDREN HAVE AUTISM?
Not a straight forward question
Could:
- Count all children with diagnosis
- Count children with statement of special needs
- Examine all children of a certain age and see how many meet criteria
Difficulties:
- Variable diagnostic criteria
- Inaccurate reporting
- Plausibility
Incidence = true rate
Prevalence = recorded rate
Scott et al 2002: UK prevalence of 0.6% with broad diagnosis ( 57 in 10,000)
Croen et al 2002: California prevalence of 14.9 in 10,000
Lingham et al 2003: London prevalence of 26 in 10,000
Could be under / over diagnosing
HOW HAVE THE NUMBERS CHANGED?
“autism epidemic”?
WHAT IS AUTISM?
Lorna Wing’s triad of impairments
- Difficulties in social interaction
- Difficulties in communication
- Lack of imagination / repetitive interests
Heterogenous - no two people are the same
Classical autism, Aspergers syndrome / High Functioning Autism (HFA), Pervasive Developmental
Disorder Not Otherwise Specified (PDD-NOS)
PDD-NOS :not sure where else to put them
PDD-NOS: absence of repetitive behaviours or communication deficits
Concurrent learning difficulties and epilepsy common in autism
Moldin (2006): social impairments are what characterise autism from other developmental disorders
The autistic spectrum contains a wide range of intellectual ability
Fombonne (1999):
- 19% no intellectual impairments
- 42% severe learning difficulties
DIAGNOSIS
Not commonly diagnosed before 2 years
GP sees child - can use basic checklists
- CHAT (Checklist for Autism in Toddlers)
- CARS (Childhood Autism Rating Scale)
Conclusive diagnosis from:
- Clinical observation - does child meet criteria? (DSM-IV)
- Diagnostic interviews: ADOS / ADI / DISCO
ADOS:
- Autism Diagnostic Observation Schedule
- 4 levels depending on verbal abilities of participant
- Children - games, books etc and observe behaviour
- Adults - interviews plus some puzzles, requires a lot of training
- US formalised procedure
ADI:
- Autism Diagnostic Interview
- For parents
- Structured interview
- Requires some training
- Not so useful for adults
DISCO
- Diagnostic interview for social and communicative disorders (Wing et al., 2002)
- Detailed - which bits of social interaction does this child have difficulty with - what do we need to
target?
DSM-V (in revision) - shorter and simpler list but may still be revised
No Aspergers!
, Combine social and communication symptoms
1. Clinically significant, persistent deficits in social communication and interactions, as manifest by all of
the following:
a) Marked deficits in nonverbal and verbal communication used for social interaction
b) Lack of social reciprocity;
c) Failure to develop and maintain peer relationships appropriate to developmental level
2. Restricted, repetitive patterns of behaviour, interests, and activities, as manifested by at least TWO of
the following:
a) Stereotyped motor or verbal behaviors, or unusual sensory behaviours
b) Excessive adherence to routines and ritualized patterns of behaviour
c) Restricted, fixated interests
3. Symptoms must be present in early childhood (but may not become fully manifest until social
demands exceed limited capacities)
WHAT KIND OF CHILDREN HAVE AUTISM?
Lingham et al. (2003)
- 567 children with ASD in NE London
- 85% male
- 50% typical autism
- But missing people who may have ASD but not diagnosed
- Autism prevalence increased until 1992 then plateued - this leveling off, together with the decreased
age at diagnosis suggests factors like increased recognition, greater willingness to diagnose, better
recording and awareness
HOW MANY CHILDREN HAVE AUTISM?
Not a straight forward question
Could:
- Count all children with diagnosis
- Count children with statement of special needs
- Examine all children of a certain age and see how many meet criteria
Difficulties:
- Variable diagnostic criteria
- Inaccurate reporting
- Plausibility
Incidence = true rate
Prevalence = recorded rate
Scott et al 2002: UK prevalence of 0.6% with broad diagnosis ( 57 in 10,000)
Croen et al 2002: California prevalence of 14.9 in 10,000
Lingham et al 2003: London prevalence of 26 in 10,000
Could be under / over diagnosing
HOW HAVE THE NUMBERS CHANGED?
“autism epidemic”?
