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Autism Spectrum Disorders Across The Adult Lifespan. What do we know and what do we need to know? Rebecca Charlton [email protected] www.goldagelab.co.uk 1
Autism Spectrum Disorders Across
The Adult Lifespan.
What do we know and what do we
need to know?
Rebecca Charlton
www.goldagelab.co.uk
1
Disclosure
No financial disclosures
No Conflict of Interests
Academic / Research Disclosures
– Member of the AUTISTICA Ageing and Physical
Health Study Group
– Member of the Grant Assessment Panel (A) for
the Economic and Social Research Council, UK
– External Examiner for University of Leeds
Postgraduate Degree programmes
2
Learning Outcomes
Upon conclusion of this course, learners will be able
to:
– Describe the issues relating to being an adult with
Autism Spectrum Disorders (ASD)
– Discuss the latest research examining the ageing
process in ASD
3
Overview
Background: ASD and diagnostic criteria
Evidence from childhood
Executive Function and ageing
– Group differences
– Age-assocations
Ability level and ageing
ASD traits over time
Questions to consider
4
Background
5
Autism Spectrum Disorders (ASD) are highly
heritable neurodevelopmental disorders
Primarily diagnosed in childhood
Affects ≈1% of the population
DSM-5
Currently, or by history, must meet criteria A, B, C, and D
A. Persistent deficits in social communication & interaction across
contexts, not accounted for by general developmental delays, &
manifest by all 3 criteria:
Deficits in (1) social-emotional reciprocity, (2) nonverbal communicative
behaviours for social interaction, (3) developing and maintaining relationships
B. Restricted, repetitive patterns of behaviour, interests, or activities as
manifested by at least two criteria:
(1) Stereotyped or repetitive speech, movements, or use of objects, (2)
Excessive adherence to routines, ritualized patterns behaviour, or excessive
resistance to change, (3) Highly restricted, fixated interests that are abnormal in
intensity, (4) Hyper-or hypo-reactivity to sensory input or unusual interest in
sensory aspects of environment
C. Symptoms must be present in early childhood (may not become fully
manifest until social demands exceed limited capacities
D. Symptoms together limit and impair everyday functioning
6
Why is understanding ageing in ASD
important?
Growing ageing population
Worldwide, 962 million adults are aged over 60
Suggests that over 9 million people with ASD are
aged over 60
First ASD diagnosed individuals only now
reaching old age.
7
What do we know about ageing with
ASD?
We don’t know much
8
Mukaetova-Ladinska et al., IJGP 2012
Potential difficulties in ASD impacted
by ageing
In which cognitive domains are difficulties common
for autistic individuals?
– Restricted interests & behaviours
– Aspects of executive function
What do we know about general age-related
changes?
– General decline in cognitive abilities
– Changes in physical health and sensory abilities
(hearing, sight, etc)
9
Executive Function in ASD
10
Hill, TICS 2004
Planning:
Towers Test
Executive Control:
Stroop
High = better Low = better
Studies in Children
Executive Control:
WCST
Low = better
Executive Function in Ageing
11
Baltes & Lindenberger, Psych & Aging 1997
Possible ageing trajectories
Suggested possible outcomes in ASD
(Lever & Geurts, 2016)
12
Parallel Protective /
Safeguard
Double
Jeopardy
Age
Perf
orm
ance
Age
Perf
orm
ance
Age
Perf
orm
ance
ASD
COM
ASD = Autistic group COM = Comparison group
Evidence beyond childhood
13
Evidence beyond childhood
14
Kenworthy et al.,
Neuropsych Review
2008
Wallace et al.,
JADD 2016
Childhood &
Adolescence
N=75
Adulthood
N=44
What question are we trying to
answer?
Are there differences between autistic and
non-autistic adults on measures of cognition?
– In midlife
– In older age (over 60 years)
Is the trajectory of change with age the same
in autistic and non-autistic individuals?
– Cross-sectional associations with age
– Longitudinal change
15
What question are we trying to
answer?
Focus on executive function
– Generativity (spontaneous flexibility/fluency)
– Executive control (reactive flexibility/switching)
– Planning
– Working memory
Example of other domain
– Episodic memory
16
Group differences
Group differences
Braden et al, Autism Research 2017– 16 ASD, 17 COM; Age 40-64, M=50; IQ >80, M =109
Powell et al., JADD 2017 – 29 ASD, 30 COM; Age 30-67, M=49; IQ >85, M =113
Geurts & Vissers, JADD 2012– 23 ASD, 23 COM; Age 51-83, M=64; IQ >80, M= 110
Lever & Geurts, Autism Research 2015– 23 ASD, 23 COM; Age 51-83, M=64; IQ >80, M = 110
Davids et al., JADD 2016– 30 ASD, 30 COM; Age 50-84, M=59; IQ >80, M =107
COM=Comparison Group
Group differences: Generativity
In two studies both phonemic and semantic
fluency was lower in ASD compared to COM
In one study no significant group differences
were observed
┼ 3 letters; ǁ 2 categoriesǂ 1 letter/catgeory
* * *
┼ ǂ┼ ┼ ┼ ǂǁ ǁ
Group differences: Executive Control
Card sorting tests: mixed findings
Trail Making test: mixed findings
┼ MCST persev errors; ǁ WCST Errors; ǂ TMT
B-A (sec); ∟ DKEFS
trails switching (sec)
*
*
ǁ┼ ǂ ∟
Group differences: Planning
No group differences in performance on Towers
No group differences on Zoo Map (Davids et al.)
┼ Towers total moves; ǂ Towers percentile
┼ ǂ
Group differences: Planning
No differences between groups in response time
when task demands increase
22
Davids et al JADD 2016
Group differences: Working Memory
Significantly poorer performance on spatial span
task
No significant differences on n-back accuracy
*
Group differences: Working Memory
N-back task accuracy and reaction time by load
For ASD and COM groups
Load Significant effects on accuracy & RT
Group Significant effects on RT only
Load x Group Interaction
No significant effects
Lever et al J of Ab Psych 2015
Group Differences Summary
Generativity - Mixed results
Executive Control - Mixed results
Planning - No group differences
Working Memory - Mixed results
Some group differences but perhaps less than in
childhood
25
Age trajectories
Lever et al., J of Abnormal Psychology 2016– 111 ASD, 164 COM; Age 19-79, M=47; IQ >80, M =114
Abbott et al., JADD 2018– 134 ASD; Age 18-75, M=31 (only 4 aged >60, restricted
sample Age 18-59); Abilities “in normal range”
Powell et al., JADD 2017
Geurts & Vissers, JADD 2012
Lever & Geurts, Autism Research 2015
Davids et al., JADD 2016
COM=Comparison Group
Age trajectories: Generativity
No differences with age in autistic and non-
autistic adults in two studies
Phonemic Semantic
ASD COM ASD COM
Davids et al.
Correlations
r=-.406 r=-.488 ns ns
Lever & Geurts
Regression
Age
Group
Age x Group
β=-.05
β=-.16 **
β=.03
β=-.06
β=-.16 **
β=-.13
Age trajectories: Generativity
28
One study of phonemic fluency demonstrated a
steeper age-association in non-autistic people
– ASD older = younger
– NT older < younger
Geurts & Vissers JADD 2012
Geurts & Visser
Regression
Age
Age x Group
β=-.64 ***
β=2.33 *
Age trajectories: Generativity
Mixed findings
Two studies show no differences in age-
correlations in autistic and non-autistic adults
Although note, one of these studies shows no
age-associations which is unusual
One study demonstrated “weaker” age-
associations in autistic adults
Age trajectories: Executive Control
Trails tests
ASD (18-75) n=134 ASD (18-59) n=130
TMT-A TMT-B TMT-A TMT-B
Abbott et al.
Correlations
Percentile
scores
r=.201 * r=.257 ** r=.151 r=.182 *
Trails Switching
Powell et al.
Regression
FSIQ
Sequencing
Age
Group
Age x Group
β=-.35 **
β=.60 ***
β=.33 ***
β=.18
β=.26 *
Trails B-A
Geurts & Visser
Regression
Age
Age x Group
Non-significant (not reported)
Non-significant (not reported)
Age trajectories: Executive Control
Trails tests
Main difference between these
studies is age at diagnosis
Abbott et al. participants were
tested at diagnosis in adulthood
Abbott et al. 2018
Powell et al. 2017
Age trajectories: Executive Control
ASD (18-75) n=134 ASD (18-59) n=130
ASD only Hayling Digit
Symbol
Hayling Digit
Symbol
Abbott et al.
Correlations
Percentile
scores
r=-.105 r=.204 * r=-.086 r=.226 **
ASD v COM Simons Reactive Control Proactive Control
Lever et al.,
2017
Regression
Age
Age x Group
F=14.59 ***
F= 1.09
F=0.96
F=1.07
Age trajectories: Executive Control
Different associations with age in only 2 of 5 tasks
ASD v COM MCST
Geurts & Visser
Regression
Age
Age x Group
Non-significant (not reported)
Non-significant (not reported)
Category Learning
Powell et al.
Regression
FSIQ
Age
Group
Age x Group
β=.44 **
β=-.33 **
β=-.29 **
β=.32 *
Age trajectories: Executive Control
Mixed findings
Three studies measured TMT, each revealed
different
– Both better and worse than age performance
observed
A further five measures were explored
– only two showed a different pattern of age-
associations in ASD compared to COM
– Digit symbol demonstrated better performance
with increasing age than age-norms
Age trajectories: Planning
Towers tests
No significant correlations observed with age for
ASD or COM groups
ASD COM
Davids et al.
Correlations
Percentile
scores
Non-significant (not reported)
Geurts & Visser
Regression
Age
Age x Group
Non-significant (not reported)
Non-significant (not reported)
Age trajectories: Planning
Zoo Map & Key Search from BADS
Zoo Map suggests poorer performance with age
in ASD
Zoo 1 (score) Zoo Total (profile)
ASD COM ASD COM
Davids et al.
Correlations
r=-.367 * r=-.423 * r=-.399 * ns
18-75 (n=134) 18-59 (n=130)
Abbott et al.
Correlations
r=-.153 r=-.224 **
Key Search (profile)
18-75 (n=134) 18-59 (n=130)
Abbott et al.
Correlations
r=.121 r=.047
Age trajectories: Planning
Mixed findings
Two studies measured Towers, and one Key
Search
– No significant age-associations
– But no age-associations in COM either
Two studies measured Zoo Map
– Both showed poorer than age-norm
performance
Age trajectories: Working Memory
Span tasks
Both studies show same pattern in ASD as in
COM
Spatial Span
Geurts & Vissers
Regression
Age
Age x Group
Non-significant (not reported)
Non-significant (not reported)
Digit Span
18-75 (n=134) 18-59 (n=130)
Abbott et al.
Correlations
r=.101 r=.072
Age trajectories: Working Memory
N-back task – difference between 2- and 0- back
Different pattern of associations in ASD and
COM
Regressions results
suggest linear & non-
linear age-effects are
important
ASD – quadratic age-
effects
COM – linear age-
effects
Lever et al J of Ab Psych 2015
Age trajectories: Working Memory
Mixed findings
Two studies show similar age-related pattern
on span tasks for ASD and COM
Suggestion of non-linear (better with age)
effects on n-back (difference between 2- and
0-back)
Age trajectories Summary
Generativity - Mixed results
Executive Control - Mixed results
Planning - Mixed results
Working Memory - Mixed results
But, based on only 7 studies
41
Ageing trajectories Summary
Parallel Safeguarding Double
Jeopardy
Generativity 2 1
Executive
Control (Trails)
1 1 1
Executive
Control (other)
3 2
Planning 3 0 2
Working Memory 2 1 0
11 (58%) 5 (26%) 3 (16%)
Ageing trajectories
There is little consistency in the executive
function results so far
Many studies are based on relatively small n’s
which may be susceptible to sampling bias
Need to be aware of the impact of our sample
characteristics
The measure we select are likely to impact
results
Other Cognitive Domains
**
Episodic Memory
Immediate recall
Mixed pattern with some studies showing group
differences and others not
Geurts & Vissers JADD 2012;
Powell et al. JADD 2018
Episodic Memory
Suggestion in one study of more difficulties in
ageing with ASD
RAVLT – Verbal Memory
Powell et al.
Regression
FSIQ
Age
Group
Age x Group
β=.32 **
β=-.23
β=-.32 **
β=-.07
Geurts & Visser
Regression
Age
Age x Group
β=-.36 *
Non-significant (not reported)
WMS Figures – Visual Memory
Geurts & Visser
Regression
Age
Age x Group
β=-.26
β=2.93 **
Episodic Memory Summary
Few studies to date
One study of verbal memory - group
differences between ASD and COM group in
later life
One other study no group differences on verbal
or visual memory
No age x group interactions on verbal memory
(2 studies)
Visual memory may be at increased risk of
decline with age in ASD (1 study)
Ageing with ASD: Questions to
consider
Are these samples representative of the ASD
population as a whole?
How does ability level influence:
–Whether trajectories are the same or
different in different ability levels?
–Relevance of any of these studies to
concerns or daily life?
Ability level
All studies described here on individuals with
abilities (IQ) in the normal range
Is profile (and change) likely to be the same in
individuals with intellectual impairments?
Are the concerns the same for different groups of
autistic adults?
49
Ageing in ASD with different ability
levels
40-year follow-up of children referred to the
Children’s Department of the Maudsley Hospital
60 Adults with ASD diagnosed as children
Mean age at diagnosis = 6 years (2-13 years)
Mean age at follow-up = 44 years (29-64 years)
Non-verbal IQ ≥70 at diagnosis
Current IQ range 50-139, but 15 individuals could
not be formally assessed
50
Howlin et al. JCPP 2013; JAACAP 2013
Prior follow-up in early adulthood in Howlin et al. JCPP 2004
Ageing in ASD with different ability
levels
ASD Characteristics:
53/60 individuals met full
ADI criteria for diagnosis
Severity scores on all
domains were lower at
follow-up
51
Howlin JAACAP 2013
Ageing in ASD with different ability
levels
Social outcomes rated on five domains:
– Educational attainment, Social Functioning,
Residential Status, Occupation, and
Relationships.
– Overall outcome (independent living,
employment, friendships & relationships).
52
Howlin
JAACAP
2013
Ageing in ASD with different ability
levels
Few people living independently
or working in highly skilled jobs
Most people in supported
accommodation and many long-
term unemployed
53
Howlin JAACAP 2013
Ageing in ASD with different ability
levels
Changes in sample over 20 years
54
Howlin
JAACAP
2013
Ageing in ASD with different ability
levels
“Best estimate” of IQ from
childhood to adulthood
Adult IQ associated with
– age at initial diagnosis
– childhood language level
– epilepsy
– gender
55
Howlin JCPP 2013
Ageing in ASD with different ability
levels
Change in cognition over 3
timepoints (n=43)
Current low function
associated with:
– behavioural disturbances
– presence of epilepsy
56
Howlin JCPP 2013; JAACAP 2013
Ageing in ASD with different ability
levels: Summary
Individual outcomes are variable
Outcomes seem better in individuals with higher IQ
Epilepsy is common in those with poorer outcomes
Outcomes may differ based on ability level
“Important outcomes” are likely to be different for
individuals with/without learning difficulties
57
Howlin JCPP 2013; JAACAP 2013
Are ASD traits stable over time?
Are any of these issues related to changes in
ASD traits over time?
– In ASD
– In comparison groups
Are ASD traits stable over time?
Siebes et al., 2018
Happé et al., 2016
Lever & Geurts,
2018
Are ASD traits stable over time?
There do not seem to be age-effects on ASD
traits over the lifespan for ASD or COM
But, older adults receiving a first diagnosis show
more ASD traits
Ageing with ASD: Questions to
consider
Are these samples representative of the ASD
population as a whole?
–Age of diagnosis
–Diagnostic criteria at diagnosis
–Ability level i.e. learning difficulties
–Co-morbidities i.e. epilepsy, ADHD, etc
Are there issues with sampling that may
influence results?
Ageing with ASD: Questions to
consider
Impact of diagnostic criteria
Age of diagnosis
Drawing conclusions about longitudinal change
from cross-sectional studies.
Cohort effects
Ageing with ASD: Questions to
consider
Who…
– is seeking a diagnosis?
– is being referred?
– is being diagnosed?
What is driving people to seek a diagnosis? What
do they hope to change?
Differences in rates of referral/diagnosis in
different countries?
Ageing with ASD: Questions to
consider
What are the mechanisms for either positive or
negative trajectories in ageing?
Are these the same or different in ASD as in
ageing?
Unanswered questions
Employment rights and support
Well-being and quality of life
Loneliness
Other cognitive changes
Theory of mind
The menopause
Sleep
Physical and Mental Health
Quality of life
Studies generally show lower quality of life (QoL)
in ASD adults
Better QoL associated with higher education,
receiving support & being in a relationship
Poorer QoL associated with being female, having
a mental health problem & higher ASD traits
Few age-effects
Mason et al., 2018
Learning Outcomes
Upon conclusion of this course, learners will be able
to:
– Describe the issues relating to being an adult with
ASD
– Discuss the latest research examining the ageing
process in ASD
67
Summary
Describe the issues relating to being an adult
with ASD
– Limited knowledge of ASD in mid- and later life or
ageing trajectories
– Few longitudinal studies
– Results may be influenced by cohort effects
– Quality of life is lower than in general population
– Ability level and comorbidities influence outcomes
– Many questions remain unanswered
Summary
Discuss the latest research examining the ageing
process in ASD
– Some evidence of adult differences in executive
function between ASD & COM but not in Planning
– Many executive functions show a typical pattern of
age-related decline
– But there may be executive functions either at risk
or protected in ageing with ASD
– Different aspects of episodic memory may age
show different age-trajectories
Thank you
