Lecture 30 - Behavioural and developmental aspects of drug dependence Flashcards Preview

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Flashcards in Lecture 30 - Behavioural and developmental aspects of drug dependence Deck (14):

Where is the dopaminergic system?

starts in the ventral tegmental area

projects forward to the nucleus accumbens and then to the prefrontal cortex

key in reinforcement of learning - ensures behaviours linked to survival are repeated - drugs can hijack this system


How does cocaine act?

blocks the re-uptake of dopamine at the synaptic cleft - causes more post-sympatic actvation


How does heroin and cannabis work?

works n the VTA -

GABA interneurons normally switch off the dompmne system - heroin binds to the opiate receptors, and open Cl channels and switches off GABA interneuron (dis-inhibition) = more dopamine released

Cannabis works in a similar way by binding to DP1 receptors


What is physiological dependence?

tolerance - homeostatic mechanisms, mean the body works against the drug more and more as you take it

withdrawal - symptoms of the reverse of the drugs effect - a result of the counteractive mechanism being in place without the drug there

Happens to everyone - but addiction is more like psychological dependence


What does psychological addition lead to?

time spent doing activities to obtain/use drug

think about using drug all the time


What causes Heroin relapse rates?

psychological dependence


how is conditioning relevant for psychological dependence?

pairing drug withdrawal with other things/situations/environments

The system becomes sensitized


With drug use, the homeostatic point changes so that normal things that gives pleasure...

no longer give the same mood response - the dopamine levels have been used up and it takes a larger increase in dopamine to get the same mood response

Drug users don't find normal things pleasurable, can't distract themselves - anhedonia


What does the orbital frontal cortex do?

Weighs up short/long term consequences

keep you on track to your goals

people with addiction so lack of activity


Does addiction cause all these CNS problems or are people who get addicted already predisposed to these behaviours?

adolescent anhedonia may continue into adulthood in some


What is the function of adolescent anhedonia?

increase in levels of boredom and disinterest is evolutionarily imporatnt as it causes pursuit of new appetite reinforcers through increase in risk taking and novelty-seeking


The full development of the brain is linear, meaning...

it starts from the back and goes forward - parts to do with judging logic and reason are last to fully develop


Young people are more vulnerable to alcohol-induced ____ impairments

memory - blackouts common in young drinkers


there is evdidence of premorbid neurobiological vulnerabilities in ....

at risk populations