ADHD ✅ Flashcards
What does ADHD consist of?
- Hyperactivity
- Impulsivity
- Inattention
What is the prevalence of ADHD amongst school-age children?
Depending on diagnostic criteria, ranges from 1-2% to 3-9%
How does the prevalence of ADHD compare between boys and girls?
3x more common in boys
What are the risk factors associated with ADHD?
- Preterm birth or low birth weight
- Maternal illicit drug use, alcohol use, or smoking during pregnancy
- Close family history of ADHD
- History of traumatic brain injury
- Exposure to some environmental toxins
- Psychosocial adversity
- High levels of family conflict
- Syndromic associations
What environmental toxin is ADHD particularly associated with?
Lead
Give an example of a syndromic association of ADHD?
Neurofibromatosis type 1
What illustrates a genetic element of ADHD?
Twin studies, adoption studies, and sibling studies have been carried out and there is a strong condorance between close family history of ADHD and risk of developing the disorder
Has a particular gene locus for ADHD been identified?
No
What pathophysiological mechanisms have been proposed in ADHD?
- Alterations in neural networks
- Frontal lobe dysfunction
- Differences in dopaminergic pathways
What evidence is there that alterations in neural networks lead to symptoms of ADHD?
Imaging studies have suggested that a number of regions of the brain may contribute to the clinical manifestations of ADHD
What regions of the brain have imaging studies shown may contribute to the clinical manifestations of ADHD?
- Frontal and parietal cortex
- Basal ganglia
- Cerebellum
- Hippocampus
- Corpus callosum
What evidence is there that ADHD is due to frontal lobe dysfunction?
- Reduction in brain volume particularly marked in pre-frontal cortex
- Pathwys connecting pre-frontal cortex and striatum shown to differ in children with ADHD
What evidence is there that there are differences in dopaminergic pathways in the brains of children with ADHD?
Stimulant medications used in the management of ADHD increase dopamine levels in the brain and produce symptomatic improvement
What is the limitation of the hypothesis that there are differences in dopaminergic pathways in brains of children with ADHD?
Complex interactions of neurotransmitters in the brain and non-specific mechansims of action of stimulant medication make it difficult to conclude that dysfunction of dopaminergic pathways is the sole aetiological factor of ADHD
What are the options for management in ADHD?
- Behavioural management
- Medications
What are the options for behavioural management in ADHD?
- Parenting support groups and courses
- Extra support in school
- CBT
- Social skills training
What needs to be ensured regarding the school in the management of ADHD?
- School is aware of diagnosis
- Appropriate strategies put in place for managing child within school environment
When is medication commenced in ADHD?
ADHD causing severe impairment to daily activities and learning
What needs to be done prior to medicating for ADHD?
- Full mental health and social assessment
- Physical examination
What does the physical examination prior to starting on medication for ADHD need to include?
- Assessment of cardiovascular risk factors
- Height
- Weight
- Heart rate
- Blood pressure
When is an ECG required prior to starting on medication for ADHD?
If significant personal or family history of cardiac disease
What are the main drugs of choice for ADHD?
- Methylphenidate
- Atomoxetine
- Dexamphetamine
- Clonidine
What preperations of methylphenidate can be dispended?
- Immediate release
- Sustained release
- Extended release
What is the first line drug in ADHD?
Methylphenidate
What kind of drug is methylphenidate?
Dopamine reuptake inhibitor
What is the mechanism of action of methylphenidate?
Blocks dopamine transporter and norepinephrine transporter centrally, which leads to inceased concentrations of dopamine and norepinephrine in the synaptic cleft
Is methylphenidate well tolerated?
Generally yes
What are the main side effects of methylphenidate?
Can affect sleep and appetite
What route is methylphenidate given?
Oral
What is the peak action of immediate release methylphenidate?
2-4 hours
What is the peak action for sustained release methylphenidate?
Extended release
What is the peak action for extended release methylphenidate?
8-12 hours
What is the half life of methylphenidate?
2-3 hours (depending on individual)
When must dosing of methylphenidate begin?
Morning
What is the dose of methylphenidate tailored to do?
Control symptoms during the day
What is the second line drug in ADHD?
Atomoxetine
How does the effect of atomoxetine compared to methylphenidate?
It has a slightly smaller effect size
When is atomoxetine useful?
- Risk of stimulant diversion by the family
- Co-morbid tic disorder/Tourette’s syndrome
- Anxiety disorder
- History of stimulant misuse
What are the advantages of atomoxetine over methylphenidate in terms of side effects?
Doesn’t affect sleep or appetite as much
What are the main side effects of atomoxetine?
- Liver problems
- Suicidal thoughts
What is the mechansim of action of atomoxetine?
Acts primarily on the norepinephrine pathway
How does the duration of action of atomoxetine compare to methylphenidate?
Atomoxetine is a longer term agent, altering the neuroendocrine environment of the brain over weeks
What is the implication of atomoxetine altering the environment of the brain over weeks?
- Takes lonegr to work
- Does not really matter when during the day it is taken
When is dexamphetamine used in ADHD?
When methylphenidate and atomoxetine have not be tolerated
What is dexamphetamine?
A stereoisomer of amphetamine
What kind of drugs are amphetamines?
Sympathomimetic agents
What is the mechanism of action of dexamphetamime?
Causes release and blocks reuptake of noradrenaline and dopamine from central neurons
When is clonidine considered in ADHD?
- Unable to tolerate usual medications
- Tic disorders
What is the mechanism of action of clonidine?
Centrally acting alpha2 adreneric agonist and imidazoline agonist
What new treatments for ADHD are under investigation?
Guanfacine hydrochloride
What is the mechanism of action of guanfacine hydrochloride?
Non-stimulant selective alpha2A adrenergic receptor agonist
How should the dose of ADHD medications be determined?
Slowly titrated upwards until no further improvement in symptoms, or sooner if side effects troublesome
How long should the dose titration take for methylphenidate and atomoxetine in ADHD?
4-6 weeks
What should happen in all children taking medication for ADHD?
Should be reviewed regularly
What side effects should be assessed for when reviewing methylphenidate in ADHD?
- Weight loss and poor appetite
- Raised blood pressure
- Sleep difficulties
What side effects should be assessed for when reviewing atomoxetine in ADHD?
Changes in behaviour, including self-harming and suicidal ideation
What should be considered regularly for all medications for ADHD?C
- Ongoing effectiveness
- Suitability of the medication
What co-morbidities often occur with ADHD?
- Developmental coordination disorder
- ASD
- Learning disabilities
- Tourette’s syndrome and tic disorders
- Oppositional defiant disorder and conduct disorder
- Mood disorders
- Anxiety disorders
- OCD
- Substance misuse
- Restless legs syndrome
- Sleep disorders
- Auditory processing disorders
- Language delay
- Persistent bed wetting
What % of children with ADHD have learning disabilities?
20-30%
What % of children with ADHD have oppositional defiant disorder?
50%
What % of children with ADHD have conduct disorder?
20%
What can oppositioanal defiant disorder (ODD) and conduct disorder (CD) lead onto inadulthood?
Antisocial personality disorder
What % of children with ADHD and ODD or CD go on to develop antisocial personality disorder?
50%
Which mood disorders in particular are common in ADHD?
- Bipolar affective disorder
- Major depressive disorders
