ADHD Flashcards
What does ADHD stand for
Attention Deficit Hyperactivity Disorder
What is ADHD
A persistent pattern (≥6 months) of inattention and/or hyperactivity-impulsivity that is more frequent and severe than is typically observed in individuals at a comparable level of development and which interferes with functioning and/or development
How common is ADHD in children
Present in around 4-5% of children
What are some factors that contribute to ADHD
Genetic predisposition
Perinatal precipitants
Psychosocial adversity
What genes are mainly involved in ADHD
Those for dopamine and serotonin transporters
What are some perinatal factors that can contribute to ADHD
- Alcohol and tobacco use during pregnancy
- Significant prematurity and perinatal hypoxia
- Other complications include unusually short or long labour, foetal distress, low forceps delivery and eclampsia
- Some evidence suggests an association with exposure to viral infection in first trimester
What are some forms of psychosocial adversity that can predispose to ADHD
Severe marital discord, lower social class, large family size, paternal criminality, maternal mental disoder, maltreatment and emotional trauma
Describe the neurobiology of ADHD
Under-active function of the frontal lobe, which is mainly responsible for reasoning, planning and impulse control
Describe the neurochemistry of ADHD
Excessively efficient dopamine-removal system, so lower levels of dopamine in synapses
Reduction of NA and serotonin
Which brain systems are involved in reward, attention and arousal?
Locus coeruleus-noradrenergic system
Mesocorticolimbic system
Describe the location of the mesocorticolimbic system
This projects from the ventral tegmental area (VTA) to the limbic system and the pre-frontal cortex
Describe the functions of the mesocorticolimbic system
It transmits dopamine and so is involved in reward-related cognition:
- Incentive salience
- Pleasure
- Positive reinforcement
It also takes part in executive functions
Where does the locus coeruleus get its name?
This is latin for blue spot as it appears azure on unstained brain tissue due to melanin
What is the function of the locus coeruleus?
This is the most important source of noradrenaline in the brain
It is broadly associated with vigilance and reaction speed
What are the functions of NA in the brain
- Enhances processing of sensory inputs
- Enhances attention
- Enhances formation and retrieval of both long and short term and working memory
- Enhances the ability of the brain to respond to inputs by changing the activity pattern in the pre-frontal cortex and other areas
Describe the location of the locus coeruleus
What are some of the impacts of childhood ADHD
- Significant difficulties parenting children with ADHD
- Increased level of home stress and high expressed emotions
- Emotional dysregulation leads to difficulties in peer relationships and reckless and dangerous behavior
- Poor problem solving ability leading to developmentally inappropriate decision making
- Significant barrier to learning and potentially exlusion from education
- Higher likelihood of antisocial behaviours
What are some of the impacts of adult ADHD
- There is an increase in the frequency of psychiatric comorbidity as compared to children
- Higher levels of criminality, antisocial behaviour
- Higher level of substance misuse - link to self-medication?
- Significant impairments in occupational function that could easily be accommodated for if diagnosis known
- Most adults will still present with residual symptoms but will no longer meet diagnostic criteria
- Possibly because there is an improvement in cortical thickness (maturation) that allows for the brain to compensate for cognitive deficits
What is the triad of ADHD symptoms?
Inattention
Hyperactivity
Impulsivity
What are some non-triad symptoms of ADHD
Impairment of self-regulation of executive functioning and emotional regulation
What are the 3 clusters of inattention symptoms in ADHD?
Cluster 1 - Focus
Cluster 2 - Distractibility
Cluster 3 - Forgetfulness/Dysexecutive
What are some cluster 1 (Focus) symptoms of ADHD?
- Difficulty sustaining attention in tasks that don’t provide high levels of stimulation or reward
- Lacking attention to detail
- Making careless mistakes in school or work assignments
- Not completing tasks
What are some cluster 2 (Distractibility) symptoms of ADHD
- Easily distracted by extraneous stimuli or unrelated thoughts
- Often appears not to listen
- Frequently daydreams or has their mind elsewhere
What are some cluster 3 (Forgetfulness/Dysexecutive) symptoms of ADHD
- Loses things
- Forgetful in daily activities
- Difficulty remembering to complete daily tasks
- Difficulty planning, managing and organising schoolwork, tasks and other activities
What are the 4 groups of hyperactivity-impulsivity symptoms in ADHD?
Physical or hyperkinetic
Loud
Social
Lack of deliberation of risks of consequences
What are some hyperkinetic or physical symptoms of ADHD
- Excessive motor activity
- Can’t sit still
- Often runs about
- Fidgeting
What are some loud symptoms of ADHD?
- Difficulty engaging in activities quietly
- Talks too much
What are some social symptoms of ADHD?
- Blurts out answers in school or work
- Difficulty in waiting their turn in conversation, games or activities
- Interrupts or intrudes on others’ conversations or games
What are some symptoms of lack of deliberation of risks or consequences in ADHD?
- Engaging in behaviours with potential for physical injury
- Impulsive decisions
- Reckless driving
How is ADHD assessed in childhood?
Ideal assessment is school observation with screening and diagnostic questionnaires and background information including exploration of early history and attachment styles
What are the diagnostic criteria for ADHD in children?
- 6 or more symptoms of inattentiveness; and/or
- 6 or more symptoms of hyperactivity and impulsiveness
- Present before 5 years
- Reported by parents, school, and seen in clinic
- Symptoms get in the way of daily life
How is ADHD assessed in adulthood
Specific adult screening tools, with clinical picture and historical picture fitting with the diagnosis
What are the diagnostic criteria for ADHD in adulthood
- In general, 5 or more of the symptoms of inattentiveness; and/or
- 5 or more of hyperactivity and impulsiveness
- Historical concerns since early age
Also effects of:
- Underachieving at work or in education
- Driving dangerously
- Difficulty making or keeping friends
- Difficulty in relationships with partners
What are some psychosocial interventions used in mild, moderate or severe ADHD in children?
- Parent training
- Social skills training
- Sleep and diet (controversial)
- Behavioural classroom management strategies
- Specific educational interventions
What is the 1st line pharmacological treatment of moderate-severe ADHD
Stimulants
What is the 2nd line pharmacological treatment of moderate-severe ADHD
SNRIs
What is the 3rd line pharmacological treatment of moderate-severe ADHD
Alpha-agonists
What are some examples of stimulants
- Methylphenidate
- Dexafetamine
- Lisdexafetamine
MOA of methylphenidate
This works by increasing dopamine by blocking the dopamine transporter
How long do methylphenidate effects last
It lasts around 4 hours, however, longer lasting preparations are available which can last 8-12 hours such as Concerta or Xaggitin
MOA of dexafetamine
This works by increasing dopamine by blocking the dopamine transporter, as well as increasing extracellular noradrenaline and possibly serotonin
How long does dexaphetamine last?
4 hours
MOA of lisdexafetamine (Elvanse)
This is a prodrug of dexafetamine which is gradually metabolised in the liver into dexafetamine, therefore giving it a 13-hour duration
What are some monitoring requirements for stimulants?
Before stimulants are started, baseline checks are require, which include:
- Height and weight
- Pulse and BP
- Cardiovascular assessment
What are some factors that require cardiological opinion before starting stimulants?
A cardiological opinion may be required in cases of congenital heart disease, FH of sudden death in under 40s, SOB, signs of heart failure, murmur or hypertension
Very common side effects of stimulants
- Appetite suppression
- Insomnia
- Headache
Common side effects of stimulants
- Nausea and vomiting
- Nervousness
- Nasopharyngitis
- Dizziness
- Tachycardia
Rare side effects of stimulants
- Aggression
- Mood changes
Example of an SNRI used in ADHD
Atomoxetine
MOA of atomoxetine
This works by increasing noradrenaline by blocking its transporters
How long does the effect of atomoxetine last?
This has a 24 hour effect, but takes 2 months to start working
Very common side effects of atomoxetine
- Loss of appetite
- Nausea and vomiting
- Increased alertness
Common side effects of atomoxetine
Constipation
Fatigue
Rare side effects of atomoxetine
- Skin rashes
- Jaundice and hepatic damage
- Aggression
Examples of alpha-agonists used in ADHD
Clonidine
Guanfacine
MOA of alpha-agonists
Agonise a2 adrenoceptors and so increase NA by reducing sympathetic stimulation
This strengthens regulation of attention and behaviour by the pre-frontal cortex via stimulation of post-synaptic a2A adrenoceptors on dendritic spines, inhibiting cAMP-mediated opening of HCN and KCNQ channels, enhancing neuronal firing
How long does guanfacine last?
Guanfacine has a 24-hour effect and takes 2 weeks to work
Very common side effects of guanfacine
- Sleepiness/fatigue
- Headache
- Stomach pain
Common side effects of guanfacine
- Loss of appetite
- Weight gain
- Poor sleep
- Bradycardia
- Postural drop
- GI upset
Rare side effects of guanfacine
- Hypotension
- Syncope
- Depression
