lecture 10 - neuropsychology ADHD

Question 1

what is the purpose of neuropsychology

Answer 1

-to understand the relationship between the brain and the behaviour

Question 2

what is clinical neuropsychology

Answer 2

-sub field of neuropsychology
-explains functional behaviour and relate this to any underlying neuropathology in order to inform treatment, rehabilitation and education

Question 3

what are neuropsychological assessments used for

Answer 3

-clinical purposes
-research

Question 4

what are test batteries
what do they assess

Answer 4

a collection of tests / assessments

-they asses
-cognitive functioning,
-emotional processing
-psychosocial skills,
-motor development

Question 5

neuropsychological assessment
-how are they standardised

Answer 5

Assessments are typically standardized
* Undergoes rigorous reliability and validity tests
* Can only be used by trained individuals
* Administered in a standardized way
* Evaluated and interpreted by trained individuals

Question 6

what is assessed in a neuropsychological assessment.

and what can they be tested with

Answer 6

-Sensory perceptual functions (tactile, visual, auditory, etc.)
* Motor functions related to speed and strength
* Attention and problem solving skills
* Language and communication skills
* Learning and memory skills
* Executive functioning

can be tested with
-a fixed battery
-a flexible battery at the discretion of the neuropsychologist (piece together different tests etc)

Question 7

how are sensory/ perceptual functions (tactile, visual, auditory) assessed

Answer 7

-example boccia bilateral coordination
-video shows girl being instructed to touch nose with alternating arms when eyes are closed,
-relies on sensory input, where her fingers are in space

Question 8

how are motor functions related to speed and strength assessed

Answer 8

-measure strength using a dynamometer,
-a machine you can rip and squeeze as hard as you can to figure out how strong your grip is

-eg finger tapping test to look at speed, you tap anytime you see a light (old method)

-hand eye coordination , place one hand behind their back, put these little peg into their holes, can sense deficit motor , hand to eye movement

Question 9

how are attention and problem solving skills assesed

Answer 9

-trials making test
-child is asked to take their pencil and draw lines to cross dots , these dots have letters and numbers
-ask child why number 1 and they go 1a, 2b, 3c, they have to keep track mentally requiring attention
-an attention and processing speed task,

Question 10

how are learning and memory skills assessed

Answer 10

-was the task we did in class which was looking at a complex picture with shapes and patterns, and then asked to draw it after class (to see how much we could remember )

Question 11

how is executive functioning assessed

Answer 11

continuous performance task
-looking at ability to inhibit responses and shift attention etc

-task in class, you clap every time you see a letter apart from the letter ‘X’

CPT and other tests of executive functioning
-used clinicall to screen to challenges with attention etc ADHD

Question 12

what is ADHD
-what types are there

Answer 12

attention deficit hyperactivity disorder
-ADHD I - inattention
-ADHD-HI - hyperactivity/impulsivity
-ADHD-C - combined

ADD is not a diagnosis (attention deficit disorder)

Question 13

ADHD - DSM 5 definition

Answer 13

ADHD categorized as a neurodevelopmental disorder because symptoms are present in childhood
* Even if diagnosis only occurs in adulthood

Question 14

what is ADHD
-criteria
-which conditions must be met (DSM5)

Answer 14

Criteria:
* At least 6 symptoms for at least 6 months → for ages 16 and under
* At least 5 symptoms for at least 6 months → for ages 17 and older

Must meet the following conditions:
* Symptoms present before age 12
* Symptoms present in two or more settings
* Evidence that symptoms interfere with functioning
* Symptoms cannot be better explained by another disorder (e.g., anxiety, dyslexia)

Question 15

ADHD- I symtoms
-more inattention related

Answer 15

Often fails to give close attention to details or makes careless mistakes in schoolwork, at work, or with other activities.
* Often does not follow through on instructions and fails to finish schoolwork, chores, or duties in the workplace(e.g., loses focus, side-tracked).
* Often avoids, dislikes, or is reluctant to do tasks that require mental effort over a long period of time (such as schoolwork or homework).
* Often loses things necessary for tasks and activities (e.g. school materials, pencils, books, tools, wallets, keys, paperwork, eyeglasses, mobile telephones).* Is often easily distracted* Is often forgetful in daily activities.

Question 16

ADHD-HI symptoms
-more hyperactive

Answer 16

Often fidgets with or taps hands or feet, or squirms in seat.
* Often leaves seat in situations when remaining seated is expected.
* Often runs about or climbs in situations where it is not appropriate (adolescents or adults may be limited to feeling restless).
* Often unable to play or take part in leisure activities quietly.
* Is often “on the go” acting as if “driven by a motor”.
* Often talks excessively.* Often blurts out an answer before a question has been completed.
* Often interrupts or intrudes on others (e.g., butts into conversations or games)

Question 17

risk factors - genetic influences
-twin studies
-family studies

Answer 17

-twin studies
-genetic influences account for 70-90% of variance (if you have a twin with ADHD theres a 70-90% chance you may also have ADHD)

-family studies
-if you have an immediate family member with an ADHD diagnosis , you are 5x more likely to experience symptoms

Research has not established causative role for individual genetic variants yet
* There isn‘t one gene!
* Likely several genes with minor effects

Question 18

risk factors - environmental influence
-factors in early development , prenatal, perinatal and postnatal
-genetics

Answer 18

Possible harmful factors in early development reliably associated with ADHD
* Prenatal association’s
:* E.g., Smoking, alcohol, illicit drug use

• Perinatal associations:
• E.g., Low birth weight, preterm birth
• Postnatal life:
• E.g., Inadequate diet, major vitamin B deficit, exposure to industrially contaminated areas, some artificial colorings, depriving institutional environment,medical illnesses…
• Genetic factors can influence exposure and susceptibility to environmental risks

Question 19

risk factors - interacting factors
genetic x environmental factors

Answer 19

ADHD risk is made up of many interacting genetic and environmental factors with different individuals affected in different ways, at different times and to different degrees
* E.g., two siblings share 50% genetics and may grow up in the same household but can still present differently

Question 20

ADHD theories
-Russel Barkley (1997)

Answer 20

-postulated that ADHD is a disorder related to executive function (EF)
-specifically inhibitory control- the ability to withhold a behaviour response
-believed that difficulties with attention were biproducts of inhibitory control deficits
i.e symptoms relate back to the same deficit

Question 21

Russell Barkley theory evidence

Answer 21

-stop signal tasks
eg CPT children with ADHD performed worse

1, habituate a response
eg ‘press the button every time a letter appears on the screen’
-participant practices the response

2. Measure commission errors
   * e.g., “Refrain from pressing the button when the letter X appears”
   * Count the number of times the participant made a response when they should have withheld it

Question 22

criticisms with Russell Barkley’s theory

Answer 22

Stop Signal Tasks have high continuous demands:
* Child must continuously process information, remember instructions, prepare for their behavioural response

• Higher intra-individual variability in ADHD groups:
• Each participant’s performance is not consistent
• Participants vary greatly from one another

Question 23

ADHD theories
-delay aversion theory

Answer 23

-the tendency to prefer smaller-immediate rewards instead of larger-delayed rewards

-eg marshmallow test of delayed on gratification
-but this could be worse for children who grew up poor ? they just learn to take what they get

Question 24

delay aversion theory
evidence
and findings
and conclusion

Answer 24

Sonuga-Barke et al. (2003)
* 156 children (3-6 years)

• Given two tasks:
• 1. EF test battery
• 2. Choice delay task (tests delay aversion)
• Computer game with a points system
• Throughout the game, they had a choice:
• Small-immediate reward – green square = 1 point
• Large-delayed reward – blue square = 2 points
• Can we predict which children are diagnosed with ADHD based on their performance?

Findings:
* ADHD – not more likely to choose the green square (small-immediate reward)
* Combining tests was able to predict 90% of the children with ADHD

• Conclusions:
• At least two mechanisms contributing to ADHD behaviours

Question 25

when can we see variability in ADHD

Answer 25

Variability in ADHD:
* Presentation of symptoms
* Onset of symptoms
* Development of symptoms
* Duration of symptoms
* Performance on different tasks (e.g., EF vs choice delay tasks)

What does variability look like in non-ADHD populations?
* Studying typical development is important for clinical research!

Question 26

variability in brain development
-grey matter and white matter development

Answer 26

studying the natural development of the brain provides insights into the process that lead to several deficits that a child might show and grow out of

-the graphs show there is variability with white matter and grey matter through your lives
white matter -increases towards as you get mid aged and then decreases as you grow old
gray matter decreases through life

Question 27

what age does white matter increase until and what does this mean

Answer 27

The brain is not yet done developing.
* White matter increases till mid-30s
* Could be due to myelination
* Frontal regions develop more slowly, which has control over attention and impulsivity.

Question 28

variability in frontal lobe development of children

Answer 28

variability in
-cortical thickness
-surface area
-volume
The inter-individual differences in development are large between children.

Question 29

how does variability cause concerns about diagnosing ADHD at a young age

Answer 29

-it causes concerns as we may not capture child’s individual trajectory

Question 30

ADHD across the lifespan
study
method and basic findings

Answer 30

Since children are still developing, can they grow out of symptoms? Shaw et al. (2013)
* Longitudinal study (childhood  adulthood)
* All participants were diagnosed with ADHD as children
* Evaluated neural correlates of symptoms across time

method
Two groups:
* Diagnosis with ADHD vs non-ADHD controls
* Evaluated neural correlates of symptoms across time

findings
-Inattentive symptoms were more like to be persist than hyperactive /impulsive symptoms
* 60% of patients no longer met criteria for ADHD

Question 31

ADHD across the lifespan
study
findings: variability in brain development causing the changes in adhd diagnosis
conclusion

Answer 31

Changes in cortical thickness in right and left hemispheres detected differences between groups
* Typical and Persisters – maintained the same developmental trajectory from childhood  adulthood
* Remitters – significantly different trajectory across time

Conclusions:
* ADHD can persist into adulthood(but not always)
* Inattention tends to persist
* Brain development might explain some inter- and intra-individual variability
* But 22-years-old may be too young to capture the full trajectory of ADHD

Question 32

how is ADHD being researched today
-brain networks

Answer 32

-looking at frontal lobe
-associated with executive functioning and adhd symptoms

Question 33

how is ADHD being researched today
-assessments and diagnosis

Answer 33

Despite brain imaging data, diagnosis doesn’t use neuroimaging information(yet)
* Reliance on:
* EF tests
* IQ test batteries
* Self-report questionnaires
* Issues with over-diagnosis of ADHD:
* Meta-analysis reports increased reports of ADHD (Kazda et al.,2021)
* Widens the ambiguity of symptoms
* Reliance on self-report alone leads to over-diagnosis

Question 34

how is ADHD being assessed today
maternal health

Answer 34

Maternal post-partum mental health challenges (after giving birth)
:* Related to ADHD symptoms when child is 8-9 years
* (Mulraney et al., 2019)

• Maternal anxiety and sleep difficulties during pregnancy
  :* Related to ADHD symptoms when child is in preschool
• (Vizzini et al., 2018)

Question 35

how is ADHD being researched today
-gut biome

Answer 35

Gut biome:
* Based on the gut-brain axis

Lower diversity of gut bacteria leads to:
*reduced production of neuroprotective factors
* higher likelihood of ADHD symptoms
* (Bull-Larsen & Mohajeri, 2019)

Question 36

how is ADHD being researched today
-cross cultural

Answer 36

Are there cultural aspects to symptoms reporting of ADHD?
* Do ADHD symptoms present similarly across countries?
* Small differences between cultures might be due to parenting differences