ADHD

Question 1

What is the heritability of autism?

Answer 1

80-90%

Question 2

What is the heritability of ADHD?

Answer 2

60-90%

Question 3

What is the triad of ADHD?

Answer 3

• Inattention
• Hyperactivity
• Impulsivity

Question 4

What are the ICD-11 criteria for ADHD?

Answer 4

• Symptoms lasting >6 months
• Inattention and/or hyperactivity-impulsivity
• Pervasive across different situations (eg. at home and at school)
• Onset <7 years (may be early signs of milestone delays etc)
• Significant distress or social impairment

Question 5

What is the epidemiology of ADHD?

Answer 5

• ~5% of the population
• M:F 3:1
• Comorbidities

Question 6

Which comorbidities is ADHD associated with?

Answer 6

• Oppositional defiant disorder (50%)
• Conduct disorder (25%)
• Learning difficulties (30%)
• Anxiety disorder (25%)
• Depressive disorders (15%)

Question 7

What is the ADHD spiral?

Answer 7

Question 8

What is the link between prefrontal dysfunction and ADHD?

Answer 8

• MRI indicates reduced PFC size and blood flow to PFC in ADHD patients
• ADHD patients demonstrate poor performance on executive function tasks
• ADHD patients demonstrate underfunctioning of dopamine system: DRD4 (receptor), DAT1 (transporter)

Question 9

What executive functions can patients with ADHD struggle with?

Answer 9

• Planning & flexible strategy
• Impulse control
• Orient to salient stimuli & adjust action
• Suppress inappropriate actions in favour of appropriate ones

Question 10

Which test can be used to assess executive function?

Answer 10

• Wisconsin card sorting test
• Stroop test (tests distractibility by other stimuli)

Question 11

What is the stroop test?

Answer 11

Question 12

What are the non-genetic biological aetiologies of ADHD?

Answer 12

• Prematurity
• Very low birth weight
• Foetal alcohol syndrome
• Associations between some food additives and childhood hyperactivity

Question 13

What are the parental factors that influence ADHD?

Answer 13

• Increased critical comments/ maltreatment/ physical discipline
• Decreased sensitivity to the child’s needs
• Maternal depression

Question 14

What is the conservative management of ADHD?

Answer 14

• CBT
• Psychoeducation
• Parental skills training
• Determine whether individuals are sensitive to specific food groups and modify diet appropriately

Question 15

What is the medical management of ADHD?

Answer 15

Medication readdresses PFC underactivity

Stimulant:
- Methylphenidate (Ritalin, Concerta XL)

Non-stimulant:
- Atomoxetine (Noradrenaline reuptake inhibitor)

Question 16

What is the mechanism of methylphenidate?

Answer 16

• Blocks the noradrenaline reuptake transporters
• Blocks the dopamine transporter (DAT)
• Acts as an agonist for the post-synaptic dopamine receptor D4 (DRD4)

Question 17

What is the onset of methylphenidate action?

Answer 17

1-3 hours (rapidy absorbed and quick acting)

Question 18

In which patients is methylphenidate recommended?

Answer 18

In severe/ moderate cases of ADHD where psychological interventions have failed

Question 19

What are the common side effects of methylphenidate?

Answer 19

• Aggression/ hostility
• Decreased appetite
• Sleep disorders
• GI discomfort

Question 20

What are the less common side effects of methylphenidate?

Answer 20

• Cardiac arrythmia: baseline ECG and pulse if high risk
• Hypertension: monitor BP
• Anorexia and growth suppression: monitor height and weight (growth chart in CAMHS, BMI in adults)
• Tics

Question 21

What are the second line medications for ADHD?

Answer 21

• Dexamfetamine/ Lisdexamfetamine (Adderall)
• Guanfacine
• Atomoxetine

Question 22

What is the moa of Dexamfetamine/ Lisdexamfetamine?

Answer 22

Stimulants
- Careful titration
- Close monitoring for cardiac arrythmia, hypertension, anorexia

Question 23

What is the mechanism of Guanfacine?

Answer 23

• Alpha-adrenergic receptor agonists (non-stimulant)
• Can reduce tics
• Side effects: anxiety, decreased appetite, GI

Question 24

What is the mechanism of atomoxetine?

Answer 24

• Antidepressant: NARI (non-stimulant)
• Little - no insomnia, no increase in tics
• May help comorbid depression
• Used if concern about stimulants
• S/e: decreased appetite, GI, fatigue, probable mild growth slowing, slower to work

Question 25

What can all ADHD medications cause?

Answer 25

• Abnormal LFTs
• Potential link to increased suicidal thoughts
• BP and HR should be monitored with all medication use

Question 26

What is the DSM-V diagnostic criteria for ADHD?

Answer 26

• Children <= 16, 6 of the following features
• Patients >= 17, 5 of the following features

Question 27

What is the ‘watch and wait’ period for ADHD?

Answer 27

Following presentation, a ten-week ‘watch and wait’ period should follow to observe whether symptoms change/ resolve

Question 28

Where are children with suspected ADHD in primary care referred?

Answer 28

Following 10 week watch and wait period, referral to secondary care required:
- Paediatrician with special interest in behavioural disorders
- Local CAMHS

Question 29

How often should weight and height be monitored in children taking methylphenidate?

Answer 29

Every 6 months

Question 30

How long is the trial for methylphenidate?

Answer 30

6-week trial

Question 31

If children don’t respond to methylphenidate, but the side effects are not significant, which drug should be trialled?

Answer 31

Lisdexamfetamine

Question 32

When would dexamfetamine be started in children?

Answer 32

When they have benefitted from lisdexamfetamine, but can’t tolerate the side effects

Question 33

What are the first line drugs of choice for adults with ADHD?

Answer 33

Methylphenidate or lisdexamfetamine