2. Attention deficit hyperactivity disorder – ADHDAttention deficit hyperactivity disorder – ADHD
A condition comprising a degree of impulsivity & hyperactivity and/or
inattention to a point that is disruptive and inappropriate for developmental
level
Pervasive & present for at least 6 months
Two sub types: Inattentive and Hyperactive/impulsive
Hyperactive/impulsive subtype also referred to as hyperactivity or
hyperkinetic disorder
But what is “inappropriate”?
A condition that is, in part, socially constructed.
Definitions: ADHD (DSM-IV TR)
3. Attention deficit hyperactivity disorder – ADHDAttention deficit hyperactivity disorder – ADHD
1/10
1/20
1/50
1/100
1/200
Have a guess
Prevalence: – how common is it?
4. Attention deficit hyperactivity disorder – ADHDAttention deficit hyperactivity disorder – ADHD
UK/USA/Australia/Scandinavia
• 5% for total (mixed or just hyperactive/impulsive or just inattentive)
• About 3% for hyperactivity ( i.e. mixed or just hyperactive impulsive
• 1% for mixed ICD10 (hyperactive & inattentive)
Politics: Administrative vs. real prevalence
USA : administrative prevalence greater than real - 10% of children on
medication for ADHD (Driven by litigation)
UK: real prevalence more than administrative – about 1% UK children
between 6 and 12 yrs are medicated (see http://www.ncbi.nlm.nih.gov/pubmed/22712630 )
Prevalence
5. Attention deficit hyperactivity disorder – ADHDAttention deficit hyperactivity disorder – ADHD
Problems with :
Attention
Executive function
Neuro-psychological basis
6. Attention deficit hyperactivity disorder – ADHDAttention deficit hyperactivity disorder – ADHD
detecting a stimulus
encoding or processing information
sustaining attention to relevant stimulus whilst
filtering out others
shifting attention when appropriate
inhibiting involuntary shifting (distractibility)
organising a response to incoming information
Attention
7. Attention deficit hyperactivity disorder – ADHDAttention deficit hyperactivity disorder – ADHD
Studies suggest that the attentional problem is not at the level of
“going in”, but at the level of stimuli processing
So children with ADHD do not have difficulties with receiving
information, but with subsequent processing and selection of
appropriate response
i.e. it’s not that they don’t pay attention, but they act as if they
don’t pay attention, because they do not respond appropriately.
Attention in ADHD
8. Attention deficit hyperactivity disorder – ADHDAttention deficit hyperactivity disorder – ADHD
A set of brain functions unique to humans, concerned with self regulation,
sequencing of behaviour, flexibility, response inhibition, planning and
organisation of behaviour
Allows us to think about ourselves, what may happen in the future, and how
we can influence it. For example, these allow us to control impulses, because
we think about and consider what will happen if we do x or y. A child with
ADHD has already done x or y before the considering has started to process.
As children with ADHD get older and enter adolescence these are the areas of
function in which they get more different from their peers, precisely when we
start to ask more of them in these areas
Executive function
9. Attention deficit hyperactivity disorder – ADHDAttention deficit hyperactivity disorder – ADHD
Some diseases are “all-or-nothing”, e.g. influenza
Others are “dimensional” in that the disorder or disease fades into normality
ADHD “normal”
For children on the cusp, it is difficult to distinguish disorder from personality.
To some extent it is a socially constructed diagnosis which is a disorder “here and
now” because it is hard to accept that 5% of all children are “abnormal”
ADHD as a dimensional disorder
11. Attention deficit hyperactivity disorder – ADHDAttention deficit hyperactivity disorder – ADHD
Any intellectual activity is much more difficult for these children
both in getting started and in sustaining that activity
They have to put in far more effort for any particular task
compared to their peers – everything is at least twice as hard
This is very tiring
They will therefore do anything to avoid intellectual effort
because it is so hard
Effort avoidance
12. Attention deficit hyperactivity disorder – ADHDAttention deficit hyperactivity disorder – ADHD
Genotype – our genetic inheritance and makeup – what our DNA says, which
genes we carry
Phenotype – how our genotype is expressed . E.g. gene for cystic fibrosis results
in a phenotype that involves chest infections, digestive problems, infertility in
males. Genes for ADHD result in ADHD phenotype
Phenocopy. – when another set of factors, usually environmental, result in a set
of signs symptoms and behaviours very similar to a genetic phenotype. Most
famous example – Romanian orphans and autism
ADHD phenocopies – violence, abuse, and anxiety
Phenocopy of ADHD
13. Attention deficit hyperactivity disorder – ADHDAttention deficit hyperactivity disorder – ADHD
The infant human brain at birth is very immature in comparison to other mammals
++ growth, development, cellular interconnections and cell culling in the first year
or two
Direction and pattern of these processes is partly genetically, partly
environmentally driven
Our children’s brains are sculpted irreversibly by their early (and perhaps even
prenatal) life experiences
Children exposed to violence are hard wired to be anxious, distractible, highly
aroused in situations of conflict, and impulsively aggressive – this is largely
irreversible
Impact of early violence on brain
development
14. Attention deficit hyperactivity disorder – ADHDAttention deficit hyperactivity disorder – ADHD
Children living with violence are anxious, highly aroused, and have
raised cortisone
Although for older children this does not have the same long term
impact on brain structure, fearful highly aroused children are:
distractible/inattentive/overactive/impulsive
How? - Weinstein et al, 2000:
difficulty concentrating caused by re-experiencing trauma (PTSD)
hyperactivity caused by hyper-vigilance
Impact of current violence on behaviour
15. Attention deficit hyperactivity disorder – ADHDAttention deficit hyperactivity disorder – ADHD
Higher prevalence of violence in low income families,
including domestic abuse (DA) and child abuse
Poverty associated with other risk factors for “ADHD”
LBW and prematurity
Intrauterine exposure to illegal drugs and alcohol (itself
strongly linked to DA)
Demography of violence
16. Attention deficit hyperactivity disorder – ADHDAttention deficit hyperactivity disorder – ADHD
Aetiology:- what causes it?
Genes Exposure to
violence in
infancy
Teratogens
(esp alcohol) Prematurity/low birth weightPrematurity/low birth weight
Some of these factors are linked e.g. violence, Low birth weight, and foetal
alcohol exposure.
ADHD phenocopy
17. Attention deficit hyperactivity disorder – ADHDAttention deficit hyperactivity disorder – ADHD
treatment
• Medication
AND
• Psychological approaches
Should depend on cause but doesn’t.
Evidence base not addressed heterogeneity
17
18. Attention deficit hyperactivity disorder – ADHDAttention deficit hyperactivity disorder – ADHD
“….programmes on television in the UK exploring ADHD ……..ignored
children’s rights in that they were exploitive, contravened a child’s right to
privacy, and were certainly not in the best interests of the children involved.
They provided inaccurate presentations of ADHD with most of the
cases presented being conduct disordered children in very disadvantaged
circumstances. ….(The programmes) had a focus on these children not as in
distress, but as ….. bad. ”
Webb E. Health services: who are the best advocates for children?
Archives of Disease in Childhood 2002;87:175-177
ADHD & the Media
19. Attention deficit hyperactivity disorder – ADHDAttention deficit hyperactivity disorder – ADHD
-a badly behaved,
impulsively aggressive,
morally deficient child
ADHD media stereotype
But children with ADHD can
be impulsively anything:-
brave, empathetic, witty,
cautious, clever, unkind,
generous, reserved,
oppositional, adventurous,
imaginative, energetic,
creative, destructive, etc..
Don’t stereotype or you
will miss cases
Don’t confuse personality
with disorder
20. Attention deficit hyperactivity disorder – ADHDAttention deficit hyperactivity disorder – ADHD
Summary
ADHD is common, but under-diagnosed in the UK
Affected children form a highly heterogeneous population: each
child with ADHD requires a tailored strategy depending on context
Stimulants are effective in management (but they are not
everything)
The severity of ADHD, and adult outcomes, are strongly affected by
how a child is treated by the adults in his/her life
Further reading (for those interested ) Webb E. Arch Dis Child doi:10.1136/archdischild-2012-
303578 Poverty, maltreatment and attention deficit hyperactivity disorder
see http://adc.bmj.com/content/early/2013/04/04/archdischild-2012-303578.full