ADHD - Attention Deficit Hyperactivity Disorder

Question 1

About ADHD

Answer 1

• Characterised by symptoms of hyperactivity, impulsivity and inattention starting in childhood
• 3x as common in boys than girls (could be bias) + 4x more likely in socio-economic deprivation
• Increasing likelihood of risktaking in teens
• 2.5% prevalence in adults

Question 2

ADHD Subtypes - Predominantly inattentive

Answer 2

• Difficulty in finishing a task, following instructions
• Easily distracted

Question 3

ADHD Subtypes - Predominantly hyperactive/impulsive

Answer 3

• Difficulty in sitting still for long periods
• Fidgeting
• Speaks or acts at inappropriate times

Question 4

ADHD Subtype - Combined inattentive + hyperactive/impulsive

Answer 4

Most common subtype

Question 5

DSM-V Diagnostic Criteria - Inattention symptoms

Answer 5

At least 6 required
- Has difficulty in sustaining attention & organising tasks + activities
- Doesn’t: seem to listen when spoken to, follow instructions, or finish tasks
- Loses things necessary for tasks
- Easily distracted + forgetful

Question 6

DSM-V Diagnostic Criteria - Hyperactivity + Impulsivity Symptoms

Answer 6

At least 6 required
- Fidgets with hands / feet / squirms in seat + gets up from it
- Runs and talks excessively
- Cannot wait for their turn
- Interrupts or intrudes on others
- Always ‘on the go’
- Blurts answers before question’s completed

Question 7

More DSM-V Diagnostic Criteria

Answer 7

• Symptoms present before age of 12
• Significant impairment in social or academic/occupational functioning
• Some symptoms that cause impairment are present in 2 or more settings e.g. school/work, home, recreational
• Not due to another disorder
  e.g. autism, mood/anxiety disorder

Question 8

Aetiology of ADHD

Answer 8

• Heritability - parents/siblings of a diagnosised child are 4-5 more likely to be diagnosed
• Pre-natal exposure to alcohol + nicotine
• Premature birth + low birth weight
• Perinatal brain injury
• Environmental toxins like lead and pesticides

Question 9

ADHD Neural Dysfunction - Structural

Answer 9

• 3-4% reduced overall cortical + esp. prefrontal cortex
• Reduced grey matter esp. in frontoparietal attention network
• Reduced cortical connectivity (white matter tracts) between hemispheres and within frontoparietal attention networks

Question 10

ADHD Neural Dysfunction - Functional

Answer 10

hypoactivity in the prefrontal cortex, especially the dorsal anterior midcingulate cortex (dACC)

Question 11

ADHD Neural Dysfunction - Molecular

Answer 11

Imbalance in dopamine and noradrenaline circuits

Question 12

ADHD Neural Dysfunction - Attention System

Answer 12

Reduced volume, activity, and connectivity in brain regions also linked to the endogenous attention system

Question 13

ADHD Treatment

Answer 13

• Methylphenidate (e.g. Ritalin) and Dextroamphetamine (e.g. Attentin) are effective and commonly prescribed
• Function by blocking the reuptake of norepinephrine (NOR) and dopamine (DOP) and facilitating their release, enhancing availability in the prefrontal cortex and basal ganglia