Lecture 14 - ADHD Pt 1 Flashcards
Why are disorders in children special?
- Increased vulnerability
- Less complex/realistic view of themselves/world
- Less self-understadning
- Less past judgements to compare to
- No thoughts on future issues
- Highly dependent on adult
- Events become overly important
- More sensitive to failure/rejection/disappointment
- Problems can become insurmountable
- Behaviour has to be compared to what is appropriate for age/gender
Where does vulnerability come from?
- Severe marital discord
- Low social class
- Large family size
- Paternal criminality
- Maternal mental disorder
- Foster placement
- Maltreatment & emotional trauma
Combination of adversity = not a single factor
- Factors may lead to other childhood disorders and may influence outcome rather than onset
What are symptoms in younger children?
- Poor concentration
- Hypervigilance to perceived fear stimulus
- Stimulus avoidance
- Excessive worry
- Denial
- Rage
- Social Withdrawal
How does the brain develop in early life? (DESIRE)
- includes neuron formation, proliferation, migration, death
- Synapse formation and pruning and myelination
- By age 1 = brain is 70% of adult size, age 2 = 80% and age 5 = 90%
- Following factors are important for brain development:
- Environment
- Stimulation
- Interaction
- Responses
- Experiences
- Diet/growth factors
What are the most common disorders in children
- Can be diagnosed across whole range, 1 in 10 children have one
- Higher level of conduct, emotion disorders and hyperkinetic disorders like ADHD
- ADHD is more present in boys than girls
Is ADHD real?
- Chronic condition
- Attention deficit: impulsivity, poor concentration and easily distracted
- Hyperactivity disorder: exaggerated motor activity, fidgeting, aimless running/talking and socially intrusive
What does ADHD lead to? (dysfunction)
Dysfunction in:
- Problem solving
- Planning
- Orienting
- Alerting
- Cog flexibility
- Decision making
- Sustained attention
- Response inhibition
- Working memory
Relates to frontal cortex and executive functioning
What does ADHD lead to? (implication)
- Poor academic achievement –particularly reading
- Low intelligence
- Immaturity
- Low self-esteem
- Inability to form normal parental relationships
- Inability to form normal peer/peer relationships
- Negative view by peers
- Increased risk of substance abuse
- Increased risk of anti-social behaviour
- Abnormality is sometimes subtle –extension of normal behaviour
How is ADHD diagnosed in DSM?
- Split into clusters of symptomology
- child needs to present 6 from attentional cluster and 6 from hyperactivity cluster and presenting for significant amount of time
- Sig amount of symp before age 12 and not better explained by another disorder
- If older than 17 - only need 5 symptoms or more
What are the sub-types of ADHD?
- Predominantly inattentive: most symptoms are about inattention and <6 of hyperactivity
- Less likely to act out and may sit quietly but are not paying attention = may be overlooked and not notice symptoms of ADHD
- Predominantly hyperactive-impulse: most symptoms are hyperactivity and <6 in inattentional
- Combined Hyperactive-impulsive and inattentive: 6+ symptoms in both categories = most children with ADHD are combined
- Other specified ADHD = last category for ADHD not fitting into other subtypes
- Subtype does not affect treatment type
Differential diagnosis in ADHD
- Go to GP first to assess hyperthyroidism, anemia, abuse, sleep impairment etc
- Other mental health conditions or fetal alcohol syndrome
- ADHD has comorbidities
- Requires child psychiatrist for final diagnosis
What is the epidemiology for ADHD? (Stats)
- UK: 0.5/1000 in 1970, but 3/1000 in 1990
- Children in US/UK have greater ADHD than other eastern countries
- 5.2% US adults have ADHD = not just a childhood developmental disorder
- Boys more likely to have ADHD in all sub-types
- Young>old - HI type
- Poor>rich - HI type but rich more likely to receive treatment
What was the aetiology of ADHD?
- PCB
- Foetal exposure to alcohol
- Maternal smoking
- Pregnancy and delivery complications = nonsig evidence
- Psychological adversity = nonsig evidence
- Children born preterm/born low birth weight = more likely to have diagnosis of ADHD
What are the pre/neo-natal effects for aetiology?
- Foetal exposure – toxins such as PCBs, lead, mercury
- Maternal alcohol – hyperactivity, impulsivity (FAS)
- Maternal tobacco – 2.7 fold increase in ADHD reduces placental function
- Link between nicotine and dopamine function can affect neuronal proliferation/differentiation
- Hypoactivity of dopamine/noradrenaline
- Birth complications – pre-eclampsia, hypoxia, prematurity, maternal age/health,malnutrition, duration of labour
- IUGR: intrauterine growth retardation
- All lead to low birth weight
What are the genetic aetiologies?
- High heritability - 75%
- High MZ twin concordance
- Many candidate gene association studies and Genome wide association studies
- Numerous candidates
- genetic candidates have high biological efficacy
- Linked to dopamine function: receptors and transporters
- Linked to Serotonin function: receptors and transporters
- Linked to noradrenergic function: transporters
- D4 receptor gene strongest candidate