Addiction - Neurobiology

Question 1

What are the 6 main features in the ICD-10 criteria of dependence?

Answer 1

A strong desire to take the substance / difficulties controlling substance use / physiological withdrawal state / tolerance / neglect of alternative pleasures / persistence despite evidence of harm

Question 2

What is the CAGE acronym for symptoms of dependence?

Answer 2

Cut-down, annoyed, guilty, eye-opener

Question 3

What is the neurotransmitter in the reward pathway?

Answer 3

Dopamine

Question 4

What is the medical term for the reward pathway?

Answer 4

Mesolimbic pathway

Question 5

What does dopaminergic activity in the mesolimbic pathway do?

Answer 5

It is a motivating signal which incentivises behaviour and is involved in normal pleasurable experiences

Question 6

As more dopamine is released in the mesolimbic pathway, what happens?

Answer 6

It makes you want to take/do the thing more

Question 7

What happens if you overstimulate the reward pathway by doing something addictive again and again?

Answer 7

Dopamine receptors will downregulate and a tolerance to reward will develop

Question 8

Developing a tolerance to a trigger means what?

Answer 8

You will need more of the thing/substance ti achieve the same effect

Question 9

When you develop tolerance to reward, what effect does this have on normal experiences?

Answer 9

They don’t evoke an adequate reward response

Question 10

What is positive reinforcement? When does this occur?

Answer 10

Drug taking is driven by reward / In the initial stages of drug taking

Question 11

What is negative reinforcement?

Answer 11

Drug taking is driven by wanting to avoid feeling rubbish (i.e. it becomes a thirst)

Question 12

In simple terms, what is the role of the pre-frontal cortex?

Answer 12

To ‘put the brakes’ on the reward pathway and help us make sound decisions

Question 13

What part of the cortex develops last?

Answer 13

The prefrontal cortex

Question 14

What is the abnormal significance of the back to front maturation of the frontal lobe cortex?

Answer 14

Areas which mediate executive functioning mature later than limbic (emotional) areas

Question 15

What is responsible for the increased death rate in adolescents?

Answer 15

They have strong stimulus reward (adult response, developed) but minimal judgement or impulse control (child response, underdeveloped)

Question 16

Addictive drugs provide a potent signal that disrupts what?

Answer 16

Normal dopamine related learning in the PFC

Question 17

What is the relationship between addictive behaviour and age?

Answer 17

Once you start doing an addictive behaviour, the pathways get wired into the brain. Therefore, the younger age of onset, the longer the addictive behaviour lasts

Question 18

Actions surrounding an addiction (for example, opening a cigarette packet) can make a person want to do it more. This is due to the consolidation and expression of drug stimulus learning which takes place in which areas of the brain?

Answer 18

Amygdala, striatum and hippocampus

Question 19

Learned drug associations can cue what?

Answer 19

Internal states of cravings

Question 20

The orbitofrontal cortex is the key creator of what? Activity of the OFC increases in addicts when presented with what?

Answer 20

Motivation to act (i.e. whether we do the action or not) / drug cues

Question 21

What % of the risk of addiction is due to genetic factors?

Answer 21

40-60%

Question 22

Genetic factors which increase risk of addiction may affect what things?

Answer 22

The way our body metabolically responds to drugs / how rewarding we find drug taking / behavioural traits that predispose us to drug taking

Question 23

What effect on addiction does having low dopamine receptors have?

Answer 23

It increases the chance of addiction since these people don’t get as much pleasure from normal activities

Question 24

Acute stress has what effect on drug taking behaviours?

Answer 24

It triggers the release of dopamine in the reward pathway which can motivate drug seeking in dependent individuals

Question 25

Chronic stress has what effect on dopamine?

Answer 25

It dampens the dopaminergic activity through downregulation of dopamine receptors (i.e. reduces sensitivity to normal rewards)