People and Illness Flashcards
What are the main clinical features which define ADHD?
- Inattention
Lacks of persistence in activities requiring concentration
Selected attention - distraction
Sustained attention - problem-solving - Impulsivity
Inappropriate/defective filtering of information
Poor awareness of risk makes individuals accident-prone
Social disinhibition, excessive talking
Poor peer relationships, aggression, emotional dysregulation - Hyperactivity
Psychomotor agitation
Restless, fidgety, disorganised, ill-regulated
Discuss the influence of genetics on the development of ADHD
Candidate ADHD susceptibility genes: those involved in reward pathways, dopamine regulation
Associated learning disorders: Fragile X, Klinefelter & Williams syndromes
Genetic-environment interactions - genes can increase or reduce the impact of the environment on the development of ADHD
Which characteristics might be present in an fMRI of an individual with ADHD?
Reduced frontoparietal volume
Right dorsolateral prefrontal lobe reduced
Smaller basal ganglia
Smaller cerebellar vermis
Attentional systems involved: anterior fronto-striatal networks
Posterior parieto-cerebellar circuits
Which co-morbidities is ADHD associated with?
- Mood disorders
- Tic disorders e.g. Tourette syndrome
- Insomnia
- Anxiety
- Learning disorders
- Behavioural difficulties: ODD/CD (oppositional defiant disorder/conduct disorder)
- Social communication difficulties
Describe the process of development of attention in children
- 0-12 months: fleeting; focus very briefly, quickly distracted
- 1-2 years: rigid; can attend to task of their own choosing
- 2-3 years: single-channelled; can only focus on one thing at a time
- 3-4 years: focus; attention is single-channelled but child can control this
- 4-5 years: dual-channelled; can do task & listen to someone at same time
- 5+ years: integrated; mature attention control
Briefly outline the process of assessment of ADHD
- No specific diagnostic test, so assessment includes:
- Direct observations in >1 setting: ADHD must be pervasive
- Structured questionnaires given to reliable informants
- Psychoeducational assessment
- Identifying co-morbid mental health problems
- Developmental history
Which structured questionnaires are commonly used in the assessment of ADHD?
- SNAP-IV Teacher and Parent Rating Scale
- Conners Scale for ADHD Assessment
What type of information would be relevant when taking a history for assessment of ADHD?
- Past history
Pregnancy/delivery (any alcohol/illicit drugs?)
Patterns of feeding, sleeping, play
Activity levels, impulsivity, inattention - Medical history
Head injury
Hearing problems
“Tics”/funny turns/seizures - Family history
Learning difficulties in the family
Stressors in the family
Child’s care history
Discuss the use of behavioural parent training in the management of ADHD
- Encourage consistency in managing less desirable behaviour
- Do not personalise behaviour problems
- Routines, countdowns, reminders
- Planned ignoring, time-outs, quiet time
- Positively reinforce appropriate behaviour
- Clear rules with consequences
Discuss the use of behavioural training in schools to manage ADHD
Management of the environment
* Provide a calm environment, reducing background noise
* Avoid too many distracting stimuli when wanting a child to concentrate
* Initially avoid situations that require quiet, still behaviour for long periods of time
* Maintain structure & supervision longer than you think necessary
Behavioural management
* Do not give instructions without first gaining the child’s attention
* Give clear, direct, short instructions & provide visual aids if needed
* Ask child to repeat back instructions
* Improve concentration skills with activities the child enjoys
* Plan ahead for problem situations
* Model good listening skills
Outline the mechanism of action of methylphenidate, including different preparations & dosages
Methylphenidate aka ritalin, concerta, equasym, medikinet
Blocks dopamine and noradrenaline reuptake by blocking transporter: increases NA and DA
Immediate release tablets: 5mg 3-4x a day
Modified release/sustained release preparations available, 8-12h duration
Usually give long-acting in the morning and short-acting in late afternoon
Drug holidays required
Outline the mechanism of action of dexamphetamine, including different preparations & dosages
Dexamphetamine acts to release dopamine stored in presynaptic vesicles, whilst blocking reuptake via transporter, increasing dopamine
Dexedrine 5mg: immediate release; max dose 20-40mg
Elvanse: lisdexamphetamine dimesylate, sustained release, 13h duration
* Increases available NA and DA
* Max dose 70mg
* Pro-drug, converted to dexamphetamine via first-pass metabolism
* Less susceptible to abuse
Outline the mechanism of action of atomoxetine
Noradrenaline reuptake inhibitor: enhances noradrenaline transmission in prefrontal cortex
Takes time to have an effect, approx 6 weeks, but no drug holidays required
Effective for co-morbid anxiety, depression
Outline the mechanism of action of guanfacine, including dosage and preparations
Selective central alpha 2a adrenergic receptor agonist
Stops the effect of noradrenaline at the synapse
Acts on prefrontal cortex, not nucleus accumbens, reducing the potential for abuse
Helpful with sleep & appetite issues; significant improvement within 3 weeks
Oral prolonged release tablet formulation
Basal metabolic rate is higher in children than adults, so dosage relative to body weight is higher/more frequent
Discuss the side-effects of psychostimulants and ways to manage them
- Anorexia, nausea, weight loss, growth concerns
- Sleep difficulties
- Dizziness, headache, abdominal pain
- Involuntary movements or tics
- Dysphoria, agitation
- Tachycardia, hypertension
- Syncope suspected to have cardiac origin
Stop medication & seek specialist advice
Discuss the side-effects of atomoxetine
- Nausea/vomiting
- Excessive tiredness
- Insomnia
- Abdominal pain, appetite suppression, weight loss, constipation
- Headaches
- Mood swings/rage, suicidal ideation
- Hepatic impairment (monitor LFTs)
- Tachycardia, hypertension
Discuss the side-effects of guanfacine and clonidine
Guanfacine
* Sedation
* Dizziness
* Hypotension: monitor BP and heart rate
* Precaution when combined with pscyhostimulants, reports of sudden death
Clonidine
* Paradoxical hypertension
* Paradoxical sleep disturbance
How would you manage side-effects like loss of appetite and insomnia?
Loss of appetite
* Caloric augmentation
* Administer medication with food
* Drug holidays
* Monitor height and weight
* Dietetic advice
Insomnia
* Administer medication earlier in the afternoon or reduce evening dose
* Sleep hygiene advice
* Melatonin
Discuss how ADHD medication monitoring is carried out
- Height and weight: on a growth chart every 6 months
- Heart rate and BP: repeat at every dose adjustment and every 6 months, ECG if treatment affects QT interval
- Complete history
Concomitant medicines
Past, present medical history
Psychiatric disorders
Family history of sudden cardiac and unexplained death - Contraindications
Depression, anorexia, suicidal tendencies, psychosis
Pre-existing cardiovascular disorders
Discuss the legal status of psychostimulant medications
- MPH and dex are schedule 2 controlled drugs (prescription only medicines)
- BNF (British National Formulary)
Prescription and requirements: form and strength of preparation
Total quantity in words & figures
Dose to be administered
28 day validity - signed & dated by prescriber
Signed on collection + proof of identity
30 day supply - Good practice: pharmacist may supply more if requested but prescriber must state why
After titration and dose stabilisation, prescribing and monitoring of ADHD medication is carried out under shared care protocol arrangements with primary care
Discuss the features which can influence the prognosis of ADHD going into adulthood
Prognosis depends on co-morbidity
* Organic disorders
* Psychiatric disorders e.g. ODD/CD
* Learning difficulties
* Which symptoms predominate & environment in which they predominate
Factors associated with persistence into adulthood
* Progressive reduction in cerebellar & hippocampal volumes
* Maternal depression, marital discord, negative parent-child interactions
* Family socioeconomic disadvantage
* Familial ADHD
Discuss the influence of arousal systems on the pathogenesis of ADHD
- Deficiency in arousal mechanisms, defective inhibitory response
- Neurons in prefrontal cortex are out of tune and can’t distinguish between important signals & background noise
- Can’t focus as all the signals are the same - easily distracted
Hypoarousal: low firing of NA and DA neurons
Need to improve the “signal to noise” ratio; increase the drive of the arousal network to improve efficiency of information processing
Hyperarousal: increased phasic firing of NA and DA neurons
Excess NA and DA stimulate additional receptors and cause the signal-to-noise detection to deteriorate
Need to downregulate neuronal activity to return to normal phasic firing
Discuss the anatomical changes in the cortical grey matter which take place during the development of the adolescent brain
- Matures from back to front; increases and then decreases in volume as white matter increases
- Maximum density of cortex is achieved in sensorimotor cortex first, while prefrontal cortex is last (superior temporal gyrus is last to change)
- Massive synaptic proliferation in prefrontal area (early adolescence) followed by plateau phase
- Then, reduction and reorganisation via neural pruning
Discuss the anatomical changes in the subcortical grey matter which take place during the development of the adolescent brain
Basal ganglia (involved in movement, higher order cognitive & emotional functioning) matures after limbic system
Limbic system is involved in emotional regulation, reward processing, appetite and pleasure seeking