Week 9 - The neurobiology and management of ADHD

Question 1

What are the two main types of symptom in ADHD?

Answer 1

Symptoms that relate to attention and imulsivity/hyperactivity

Question 2

As well as impairment in executive functions, what else do people with ADHD show impairments in?

Answer 2

• Selective attention
• Sustained attention
• Response precision
• Temporal information processing

Question 3

What are the two main processses which can drive selective attention?

Answer 3

• Endogenous attention
• Exogenous attention

Question 4

What is meant by the term selective attention?

Answer 4

The ability to process one stimulus in the presence of another potentially distracting stimuli

Question 5

What are the two ways which selective attention may be driven?

Answer 5

• Exogenous (bottom-up)
• Endogenous (top-down)

Question 6

What is exogenous attention driven by?

Answer 6

Sensory stimuli

Question 7

What is endogenous attention driven by?

Answer 7

Internal goals or desires such as hunger

Question 8

Where in the brain does the endogenous attention circuit begin?

Answer 8

The prefrontal cortex

Question 9

Where in the brain does exogenous attention begin?

Answer 9

The sensory areas

Question 10

Which type of attention is driven by a sensory stimuli such as a flash of light?

Answer 10

Exogenous attention

Question 11

What is the key difference between exogenous and endogenous attention in terms of where the brain circuits begin?

Answer 11

Exogenous attention begins in sensory areas such as the visual cortex whereas endogenous attention begins in the prefrontal cortex

Question 12

What does the superior calliculus play a role in?

Answer 12

• Receiving and processing sensory information
• Receiving projections from and sending projections to midbrain regions

Question 13

Dysfunction in the superior calliculus may result in what difficulties?

Answer 13

Filtering the appropriate sensory stimuli from an otherwise overwhelming environment

Question 14

What effect to the prefrontal cortex is noted in people with ADHD?

Answer 14

A reduction in volume

Question 15

What is meant by myelination?

Answer 15

The process by which axons of neurons are coated in a fatty insulating substance called myelin

Question 16

What is the purpose of myelination?

Answer 16

To speed up the conduction of action potentials

Question 17

What abnormality to white matter has been noted in patients with ADHD?

Answer 17

A reduction in myelin

Question 18

Which neurotransmitter is thought to be the most important for exogenous attention?

Answer 18

Acetylcholine

Question 19

Which neurotransmitter is thought to be important for endogenous attention?

Answer 19

Dopamine

Question 20

Name the three monoamine neurotransmitters

Answer 20

• Dopamine
• Serotonin
• Noradrenalin

Question 21

What are the three principal dopaminergic pathways?

Answer 21

• Mesolimbic
• Mesocortical
• Nigrostriatal

Question 22

As well as ADHD, what other conditions are dopaminergic pathways of interest regarding?

Answer 22

• Addictions
• Psychosis

Question 23

What is the nucleus accumbens involved in?

Answer 23

Motivation

Question 24

What is the nucleus accumbens of particular interest in the study of?

Answer 24

Addiction

Question 25

Abnormalities within the serotonergic pathways are thought to be the basis of which condition?

Answer 25

Depression

Question 26

What do serotonergic neurons play roles in?

Answer 26

- Sleep walking - Emotions - Moods

Question 27

What is the hippocampus involved in?

Answer 27

- Learning - Memory - Emotion - Mood

Question 28

What are noradrenergic pathways most notably involved in?

Answer 28

- Arousal - Reaction to stimuli

Question 29

What are neurons that synthesise, store and release acetylcholine known as?

Answer 29

Cholinergic

Question 30

What are cholinergic pathways involved in?

Answer 30

- Cognition - Learning - Memory

Question 31

Cholinergic function is of particular interest with regards to the study of which condition?

Answer 31

Dementia

Question 32

Where is the pons located?

Answer 32

The brain stem

Question 33

Cognitive flexibility involves which 5 areas of the brain?

Answer 33

- Ventral tegmental area - Prefrontal cortex - Basal forebrain - Amygdala - Parietal cortex

Question 34

Working memory involves which 3 areas of the brain?

Answer 34

- Ventral tegmental area - Prefrontal cortex - Locus coeruleus

Question 35

Response inhibition involves which 3 areas of the brain?

Answer 35

- Basal ganglia - Raphe nuclei - Prefrontal cortex

Question 36

Neurotransmitter is released from vesicles in the axon terminal into what?

Answer 36

The synaptic cleft

Question 37

What does the neurotransmitter cross the synaptic cleft and bind to?

Answer 37

Receptors on the cell membrane of the postsynaptic neuron

Question 38

Action potentials travel to the axon terminal in the what?

Answer 38

Presynaptic neuron

Question 39

What are the methods by which neurotransmitter can be removed from the synapse?

Answer 39

- Reuptake - Enzymatic degradation - Diffusion

Question 40

What does the gene which has been linked with ADHD code for?

Answer 40

The dopamine transporter

Question 41

What are the names of the two genes which have been linked with ADHD?

Answer 41

- SLC6A3 - DRD4

Question 42

If more dopamine transporters are available, what impact will there be on removal of dopamine from the synapse?

Answer 42

It will be removed from the synapse more effectively, meaning it has less chance to bind to receptors

Question 43

What does DRD4 code for?

Answer 43

A specific type of dopamine receptor

Question 44

If the receptor is less sensitive to dopamine, what would that mean for the postsynaptic neuron effect of dopamine binding to these receptors?

Answer 44

The usual effect of dopamine on the postsynaptic neuron would be subdued

Question 45

What does the SLC6CA3 protein create?

Answer 45

A transporter which is more efficient at removing dopamine from the synapse, which reduces the amount available to bind to receptors

Question 46

What does the DRD4 protein create?

Answer 46

Receptors with reduced sensitivity to dopamine

Question 47

What is one of the biggest indicators that ADHD may have a dopaminergic basis?

Answer 47

The fact that medication used to treat it primarily targets this neurotransmitter

Question 48

What is meant by the term descriptive statistics?

Answer 48

Data that describe or summarise features of a data set, such as the mean and standard deviation

Question 49

What is meant by the term standard deviation?

Answer 49

The spread of data around the mean value

Question 50

What is meant by the term inferential statistics?

Answer 50

Results of data or statistical analysis that allow inferences/predictions to be made from sets of data

Question 51

What is a *P* value?

Answer 51

The probability that the difference between two data sets has arisen by chance alone

Question 52

If a *P* value is close to zero, what does that mean?

Answer 52

It is less likely that the difference between two sets of data has arisen by chance (ie it is more likely that there is a genuine difference between the two groups)

Question 53

To determine whether there is a statistically significant difference between two data sets, *P* values are compared with a cut-off value known as what?

Answer 53

The *a* value (alpha value)

Question 54

What is an *a* (alpha) value?

Answer 54

The level of the *P* value is taken to denote statistical significance

Question 55

What *a* value is usually used with regards to *P* values?

Answer 55

0.05

Question 56

What is meant by the term parent training?

Answer 56

A type of training that aims to provide parents or carers with techniques for managing the behaviour of children

Question 57

What ages of children is the Incredible Years parent programme suitable for?

Answer 57

From birth to 12 years

Question 58

What are the key aims of the Incredible Years programme?

Answer 58

To support parents in developing child-centered behaviours such as play, following the child’s lead, and to ensure that parents reinforce positive behaviours in their children

Question 59

What is meant by the term between-participants design?

Answer 59

An experimental design in which different groups of participants are used for each condition

Question 60

What is meant by the term within-participants design?

Answer 60

An experimental design in which the same group of participants is used in both experimental and control conditions

Question 61

What is meant by the term experimental condition?

Answer 61

The condition in which the suspected causal variable is present

Question 62

What is meant by the term control condition?

Answer 62

The condition from which the suspected causal variable is absent

Question 63

What is meant by the term order effects?

Answer 63

An effect on an experimental outcome measure that arises from the order in which participants are tested

Question 64

What four factors are thought to compromise conditions including ADHD?

Answer 64

- Emotional or affective reactions - Psychological symptoms - Thoughts or cognitions - Behaviours

Question 65

In ADHD management, what does CBT focus on?

Answer 65

- Establishing structures and routines - Establishing clear rules and expectations for key settings (eg work/school/home) - Social skills with peers - Problem solving - Active listening skills - Dealing with and expressing feelings

Question 66

What is meant by the term psychostimulant drugs?

Answer 66

A class of drugs that typically increase activity of the central nervous system

Question 67

When were psychostimulant drugs first discovered?

Answer 67

The 1930s

Question 68

Which neurotransmitters fall into the category of monoamines?

Answer 68

- Dopamine - Noradrenaline - Serotonin

Question 69

What is the role of the neurotransmitter transporter?

Answer 69

The transporter is normally responsible for removing neurotransmitter from the synapse

Question 70

How does methylphenidate work?

Answer 70

By blocking the transporter (reuptake channel)

Question 71

What effects does dopamine have at the synapse?

Answer 71

- Blocking transporters (uptake channels) - Displacing dopamine from vesicles in the presynaptic neuron, which can then be transported into the synapse

Question 72

What percentage of people discontinue treatment with long-acting ADHD drugs?

Answer 72

19%

Question 73

What percentage of people discontinue treatment with short-acting ADHD drugs?

Answer 73

38%

Question 74

What is the only non-stimulant drug treatment for ADHD currently available?

Answer 74

Atomoxetine

Question 75

What role does the superior calliculus have in the brain?

Answer 75

It is part of the circuitry involved in selective attention and processing sensory information

Question 76

What is synaptophysin?

Answer 76

A protein which aids release of neurotransmitter by interacting with synaptic vesicles

Question 77

Where in the brain is the superior calliculus found?

Answer 77

The midbrain

Question 78

Aside from blocking reuptake channels, what other effect does amphetamine have at the synapse?

Answer 78

It can displace dopamine from the vesicles within the presynaptic neuron, which can then be transported into the synapse

Question 79

Methylphenidate and amphetamine both have what kind of effect on dopaminergic activity within the brain?

Answer 79

They increase it