ADHD (DONE) Flashcards
ADHD overview
Prevalent debilitating disorder
Persistent developmentally, inappropriate levels of overactivity, inattention or impulsivity
No biomedical test
Diagnosis based on observation on behavioural symptoms
9 symptoms across 2 domains
Can be combined type or dominant in one or other form
ADHD- predominantly inattentive type
Fails to give close attention Does not appear to listen Struggles to follow instruction Difficulty with organization Loses things Easily distracted Forgetful in daily activities Avoids tasks requiring sustained mental effort
ADHD- predominantly hyperactive/impulsive type
Fidgets or squirms in chair Difficulty remaining seated Runs about or climbs excessively Difficulty engaging in activities quietly Talks excessively Blurts out answers Difficulty waiting Interrupts or intrudes
ADHD- combined type
Individual meets both sets of inattention and hyperactive/impulsive criteria
ADHD differential diagnosis
Sensory impairment Epilepsy and related states Effects of head injury Acute or chronic medical illness Poor nutrition Sleep disorders Side effects of medication School or classroom difficulties
ADHD potential causes
Genetics- inherited polymorphisms Bad parenting Broken homes- cause or effect Alcohol and tobacco exposure Low birthweight Poor diet Childhood illness
ADHD genetics
5 times increased risk to members of the family
More likely in identical twins
Greater risk of inheritance through males
Multiple genes involves
Gene for dopamine D4 implicated
Neuropathology
Reduced brain size
Reduced size of particular nuceli- striatum, prefrontal cortex white matter, corpus callosum
DrD4 associated with reduced cortical thickening, resolved in adolescence
Neurophysiology
EEG studies show reduced response to stimuli and immature patterns of activity
Blood flow studies how reduced flow in areas of caudate nucleus, striatum and frontal areas
Neurochemistry
Dopamine- affected by psychostimulants
Noradrenaline- affected by psychostimulants; reduced metabolites in the urine of children with ADHD
ADHD educational difficulties
90% under-productive with school work 90% underachieve 20% reading difficulties 60% serious handwriting difficulties 30% drop out of school Only 5% complete further education
ADGD Psychosocial factors
Parenting more of a challenge
Importance of good parenting crucial
Effects on attachment relationship
ADHD interventions
Psychological treatments
Medical treatments- reserved for severely affected
Educational interventions
Social interventions
Treating ADHD- NICE guidance
In all preschool and school-age children and young people with mild to moderate ADHD, drug treatment should not be first line
Parent training/education programmes first line- group based/individual
Drug treatment reserved for severe ADHD in school age children and young people- part of comprehensive treatment plan with psychological, behavioural and educational interventions
Pharmacotherapy for ADHD
Amphetamine and methylphenidate proven as best therapy
If refractory to one, the other generally works
Most effective drugs: enhance DA and NA function, rapid onset of action with no ceiling effect, increase in DA efflux not limited to cortex
Choice of drug treatment
Methylphenidate- generally first choice
Atomoxetine- if other tics, Tourette’s syndrome, anxiety disorder, stimulant misuse or risk of stimulant diversion are present
Dexamphetamine- only if other drugs ineffective at raised doses
Decide which drug treatment to use based on:
Comorbidities Different adverse effects Potential problems with compliance Potential for drug diversion and misuse Preferences of the child or young person and their parent or carer
Methylphenidate
Stimulant- CD 2 Dopamine reuptake inhibitor VMAT2 inhibitor Ritalin- immediate release Concerta XL- once daily Daytrana- transdermal patch
Atomoxetine
Non-stimulant- POM
Noradrenaline reuptake inhibitor
Increases NA, DA and 5-HT levels in PFC
e.g. Strattera
Dexamphetamine
Dopamine reuptake inhibitor, catecholamine releasing agent
Actively transported into cells, competitively inhibits DAT
Inhibitors of VMAT2
Vesicular pools displaced and NA/DA released
Inhibitors of MAO
CD2
A2 agonists
Clonidine and guanfacine- POM
Used off label for many years, esp. if tics present
Guanfacine clear effects in clinical trials
Thought to modulate noradrenergic tone in the PFC
Other non-licensed medications
Bupropion- weak dopamine reuptake inhibitor, used off label, moderate efficacy
Modafinil- licensed for treatment of narcolepsy, weak DA reuptake inhibitor, no SERT or NET activity, withdrawn for use in children despite significant activity die to side effects
Atomoxetine monitoring
Closely observe children or young people for agitation, irritability, suicidal thinking and self harming behaviour, particularly during the initial months of treatment or after a dose change
Liver damage in rare cases
Treatment of adults
Methylphenidate normally first line treatment
Consider atomoxetine or dexamphetamine if symptoms do not respond to methylphenidate or the person is intolerant after 6 weeks
Selection of appropriate medications
Immediate release preparations if more flexible dosing is required or during initial titration
If there is a choice of more than one drug, use the drug of lowest overall cost
Advantages of modified release preparations for ADHD
PK profile
Improved adherence
Reduced stigma (drug does not need to be taken at school)
Reduced problems of storing and administering CDs in school
Abuse liability
ADHD and addiction
Consider atomoxetine as first line treatment if there are concerns about drug misuse and diversion
Caution if prescribing dexamphetamine to people at risk of stimulant misuse or diversion
NICE guidance on drug choice
Methylphenidate for ADHD without significant comorbidity
Methylphenidate for ADHD with comorbid conduct disorder
Methylphenidate or atomoxetine when tics, Tourette’s syndrome, anxiety disorder, stimulant misuse or risk of stimulant diversion present
Atomoxetine if methylphenidate has been tried and has been ineffective at the max dose, or the child intolerant to low or moderate doses of methylphenidate
ADHD major areas affected
Vigilance- attention
Cognitive control- executive function, working memory, response inhibition
Motivation- processing reward, timing of reward
