ADHD Flashcards
what does ADHD stand for?
attention deficit hyperactivity disorder
prevalence
7.2%, most common behaviour disorder that shows itself in childhood
how much more likely are boys to be diagnosed while in school?
10 times
ration of men to women diagnosed in adulthood
2:1
concerns around the prevalence of ADHD
has appeared to be the more common in Western countries, especially US
apparent increase un disorder rates over time
several reviews of prevalence rates found:
high degree of variability between estimates
no significant variability by geographical location or year of study
what is ADHD most often associated with?
aggression conduct disorder learning disabilities anxiety low self esteem
DSM 5 diagnostic criteria
a persistent pattern of inattention and/or hyperactivity-impulsivity that interferes with functioning or development
DSM 5 diagnostic criteria (extra specifications)
• 6 or more symptoms of inattention/hyperactivity-impulsivity (5 or more if aged
17+) that have persisted for at least 6 months
• Several symptoms were present before age 12
• Symptoms occur in two or more settings
• Symptoms interfere with, or reduce the quality of social, school, or work
functioning
• The symptoms are not better explained by another mental disorder`
inattention symptoms
Often fails to give close attention to details or makes careless mistakes in schoolwork, at work, or with other
activities.
Often has trouble holding attention on tasks or play activities.
Often does not seem to listen when spoken to directly.
Often does not follow through on instructions and fails to finish schoolwork, chores, or duties in the workplace
Often has trouble organizing tasks and activities.
Often avoids, dislikes, or is reluctant to do tasks that require mental effort over a long period of time
Often loses things necessary for tasks and activities
hyperactivity/ impulsivity symptoms
fidgets with or taps hands and feet, squirms in seat
often leaves seat when expected to stay seated
often runs and climbs in situations where it is not appropriate to do so
often unable to take part in leisure activities quietly
often ‘on the go’ acting as if ‘driven by a motor’
often talks excessively
often blurts out an answer before question has been completed
often has trouble waiting his or her turn
often interrupts or intrudes on others
possible causes of ADHD
not completely understood
thought to be a combination of:
-genetic factors
-brain and structure function
risk factors for the development of ADHD
those born prematurely or with a low birth weight
those with epilepsy
those with brain damage which has happened in the womb or after severe head injury in later life
rate of heritability
75%-91%
what die Larsson et al., 2014 twin study show?
88% heritability
that shared environment was not significant
what heritability factors can be associated with future course of ADHD symptoms?
genetic risk factors, cognition and neuroimaging
role of the prefrontal cortex (damage causes…)
distractibility forgetfulness impulsivity poor planning hyperactivity
what are the symptoms of ADHD similar to?
those produced by damage to the prefrontal cortex
what do those with ADHD have consistent functional abnormalities in?
brain areas related to inhibition and attention
brain areas related to inhibition
inferior frontal cortex
supplementary motor area
anterior cingulate cortex
area of the brain related to attention
dorsolateral prefrontal cortex
parietal
cerebellar areas
role of corpus a callosum in ADHD
consistent evidence it is involved
consistently indicated those with ADHD have a smaller corpus callosum
others suggest the corpus callosum is still implicated but volume is similar to those without ADHD, rather the white matter integrity is compromised
dopaminergic transmission in ADHD
underactivity of dopaminergic transmission has been implicated
evidence for dopaminergic transmission decrease in ADHD
dopamine agonists (methylphenidate) alleviate ADHD symptoms
striatal dopamine plays an important role in the abnormal cognitive-task related processing in ADHD
genetic studies have implicated dopamine receptor genes in the aetiology of ADHD
low levels of dopamine receptor stimulation impairs the functioning of the prefrontal cortex
most common ADHD treatment?
methylphenidate (ritalin)
what does methylphenidate do? (Ritalin)
inhibits the reuptake of dopamine
lends additional support for a role of dopamine transmission in ADHD
why is dosage of Ritalin important?
too low: no effect
too high: increased activity levels disrupting child’s attention and cognition
