ADDICITION

Question 1

Define substance abuse?

Answer 1

Frequent and excessive use of substance for non-medical reasons, bring in damage to releationship and daily functioning

In addition it
- compulsive substance taking
- lives centered around a substance
- tolerance and withdrawal symptoms

Question 2

What’s the critical role of dopamine?

Answer 2

All these drugs share the ability to increase dopamine release in a brain area called nucleus accumbens
The terminal region of the mesolimbic pathway
Dopamine release in nucleas accumbens is increasing during natural reward like food and water

Question 3

Whats the stages of addiction?

Answer 3

Initiation - first taking of a drug probably by choice and for pleasure
Maintance - drug taking driven by compulsion not necessarily accompanied by pleasure
Abstinence - absence of drug taking, although the drive may still be present
Relapse - reinstatement of drug taking driven by craving

Question 4

Why does the drive to take drugs increase, whereas the hit often decrease?

Answer 4

Hedonic impact - the hit
- in most cases this is the drive for initiation
- the hit reduce stress, peer pressure
- often dimishes in the maintance stage

Compulsion
- drug seeking to the detriment of other behaviours vital for survival
- often becomes enhanced during the maintenance stage

Compulsion to take the drug increases, but the pleasure decreases

Question 5

Describe tolerance?

Answer 5

The decreased effect of a drug over repeated use
- therefore more drug required to give behavioural effect

Animals pretreated with LSD show a reduced behavioural response
Compared to animals pretreated with saline

Question 6

Describe sensitisation?

Answer 6

The increased effect of a drug over repeated use
- occurs with many behaviours

Amphetamine causes an increase in circling behaviour, compared to saline group
Increasing circling behaviour is arguemnted on repeated treatment
Which has no effect in the saline treated group

Question 7

Define the two components of drug taking behaviour?

Answer 7

Hedonic impact - liking termed
Accounts for the initial hit
Dimishs over repeated drugs- taking (tolerance)

Motivation - termed wanting
- accounts for the motivational drive, distinct from pleasure
- increase over repeated drug-taking - sensitisation

Question 8

Effect of amphetamine on cue-conditioned behaviour and hedonic reactions?

Answer 8

Dissociation of liking and wanting

Question 9

Pharamacological treatment for addiction?

Answer 9

Detoxification - progressively reduce dose
Agonist therapy - use similar but less harmful drugs
- methadone

Antagonist therapy - drugs which prevent or change the effect of the substance

Pharamacological methods alone are rarely effective
All treatments require individual to be motivated to abstain

Question 10

Whats the mesolimbic dopamine pathway?

Answer 10

Critically involved in normal motivated behaviour
Actions in this pathway may underlie the addictive potential of drugs

Dysregualtion of mesolimbic dopamine functions also implicated in schizophrenia

Question 11

Whats the basic organisation of the mesolimbic dopamine pathway?

Answer 11

Dopamine neurons project from the ventral tegmental area (VTA) to the nucleus accumbens, and also connect to the amygdala and hippocampus — this pathway is key in reward, motivation, and addiction.