L28 & 29 - Addictive behaviours

Question 1

What are the two highest causes of preventable deaths?

Answer 1

Alcohol and smoking

Question 2

Of those regularly using a drug - % will become dependent (rate does not differ widely by type of drug)

Answer 2

10-15%

Question 3

Stated below is how drug-related stimuli attain salience:

Drugs produce euphoria by activating _____ centres in the brain via release of __ in the _____ _______. The limbic system is closely tied to learning centres such as the _________, and repeatedly pairing drug-induced euphoria with drug-related stimuli creates an association

Answer 3

Pleasure/limbic, DA, nucleus accumbens, hippocampus

Question 4

The magnitude of drug-related cue-induced activation of limbic and medial prefrontal regions predicts alcohol dependent individuals who subsequent relapse

Answer 4

The magnitude of drug-related cue-induced activation of limbic and medial prefrontal regions predicts alcohol dependent individuals who subsequent relapse

Question 5

Damaging which cortical area will make smokes 100 times more likely to quit?

Answer 5

Insula cortex

*Not 100% fullproof so you wouldn’t want to get rid of insula cortex, it will affect other functions as well

Question 6

If you looked at availability of D2 receptor in the mid brain - low or high availability linked to vulnerability to addiction and greater impulsivity to seek reward (drugs)?

Answer 6

Low - where else high availability has shown to be a protective factor (but this study was done in people in their 30s who still have a lot of time to become dependent on drugs)

Question 7

What is the inverted U-shape curve hypothesis by Volkow

Answer 7

There is an optimal level of DA stimulation for the drug to be perceived as pleasant. Those with low D2 receptors will fill euphoria when drugs increase DA as in pushes it to the peak of the curve.

Those with high D2 receptors will fill unpleasant as the drug pushes them into the lower range of the curve

Question 8

The level of DA metabolism depletion appears to worsen in?

Answer 8

Chronic Methamphetamine use

*Leads to greater impulsivity for reward

Question 9

What gene influences the expression of DA D2 R density in the brain?

Answer 9

Taq1A allele - having 2 copies of the allele is associated with reduced density of D2 R in the striatum (midbrain), also predicts risk of drug dependence and may have resistance to drug treatment and learn following reward rather than from punishment

Question 10

The DA hypothesis

Answer 10

People with low density of D2 R have increased desire to seek DA stimulation - direct (e.g. cocaine) or indirect (e.g. risky behaviour) and greater neural response to DA

Question 11

Besides drug addiction, what other conditions are also characterized by low tonic levels of DA and impulsivity?

Answer 11

PD, Schiz, OCD, frontotemporal demention, Tourettte’s, Huntington’s

Question 12

T/F - The role of DA in response inhibition is known

Answer 12

F- it is unclear

Question 13

DA replacement therapy doesn’t work - may cause impulsive-compulsive behaviours instead THIS IS COUNTERINTUITIVE - This example shows that we know a little bit but it is still unclear

Answer 13

DA replacement therapy doesn’t work - may cause impulsive-compulsive behaviours instead THIS IS COUNTERINTUITIVE - This example shows that we know a little bit but it is still unclear

Question 14

In delay discounting task - would heroine dependent individuals rather take the reward asap or wait for x amount of days?

Answer 14

Take it asap

Question 15

Inhibitory control is when conscious internal goals take precedence over automatic processes

Answer 15

Inhibitory control is when conscious internal goals take precedence over automatic processes

Question 16

What brain region detects the need for greater levels of control? And which brain region implements top-down control over performance?

Answer 16

ACC, DLPFC

Question 17

in the stroop task, you are not stopping word reading but rather, amplifying the representation of the goal related task information - how is the ACC and DLPFC involved?

Answer 17

ACC detects the response conflict present in an incongruent word

DLPFC cognitive control system resolves this conflict through biasing attention to colour processing rather than word reading

Question 18

If right inferior frontal gyrus is damaged - how is the stop-signal task time affected?

Answer 18

Decreased

Question 19

Successful response inhibition requires a network of 3 regions - what are they?

Answer 19

Right Inferior frontal, Right parietal and Dorsal ACC regions

Question 20

Dependent drug users and gamblers show significantly poorer performance on control tasks - this is due to lower activity in which cortical area?

Answer 20

dorsal ACC and DLPFC

Question 21

Is prefrontal dysfunction present in drug-naïve children with a family history of drug dependence?

Answer 21

Yes

Question 22

If you use drug-related words (evocative words) - they will be slower in responding to the colour of the item as they find it harder to control and ignore drug-related stimuli in the environment

Answer 22

If you use drug-related words (evocative words) - they will be slower in responding to the colour of the item as they find it harder to control and ignore drug-related stimuli in the environment

Question 23

Does cognitive skills improve after abstinence from drugs?

Answer 23

Improvements only seen after 13 months - but only in motor abilities and info processing speed BUT no improvement in learning, memory and executive function
*We don’t look any further then after 13 months since the sample size tend to be a difficult bunch, moving around a lot

Question 24

What drug increases attention in ADHD children?

Answer 24

Ritalin

Question 25

f Ritalin is able to increase cognitive abilities in drug users - why don’t they all take it?

Answer 25

It depletes D2 receptors further - to the point that the drug users will develop PD symptoms and lead to relapse and greater impulsivity for reward

Question 26

Neuroenhancers do not have generally improved treatment outcomes for psychostimulant users in the long term - having mixed results at best

Answer 26

Neuroenhancers do not have generally improved treatment outcomes for psychostimulant users in the long term - having mixed results at best

Question 27

Why should addiction be treated like a disease?

Answer 27

1) Genetic disposition - taq1 allele
2) Neuroanatomical r/ship b/w sensitivity to drug euphoria and the transition to dependence
3) Alterations in neural mechanisms underlying rewards and control - that sensitises the individual to seek the drug in their environment, limit their ability to control their response once encountered