drugs and addiction lect 3 Flashcards
learning theory and addiction
-dominant approach
-explores drug and non drug addictions
-behaviour as a result of reinforcement and punishment
-antecedents may make sensitisation to reinforcement from substances more likely in some people e.g genetic markers or trauma
pos reinforcement
-drug using behaviour, often the effects, are pos reinforcing in early episodes
-this is the liking stage
-other reinforcement may come from social acceptance/bonding
what is contiguity
how clearly the behaviour and effect are linked in time
(pos reinforcement needs to occur as soon as poss for behaviour to be reinforced, some ROA are faster and these tend to be more addictive)
classical cond and repeated drug use
-frequent drug use can lead to cues in the environment strongly associated with the drug use e.g certain people, places etc
-initial exposure
NS (environmental stim associated with drug) - UCS (drug effects on brain) - UCR (reactions to drug, brain prepares)
-subsequent reactions
CS (environmental stim associated) - CR (compensatory reactions to drug, brain prepares)
pos reinforcement and neural systems
-drugs release DA in mesolimbic and mesocortical DA systems from the VTA
-nucleus accumbens plays important role
(-induces humans/animals to seek/ consume drugs
-animals will work hard for drug reward, especially psychostimulants
-cues associated with drugs will trigger drug seeking in humans and animals)
neg reinforcement
-use of drug can remove unpleasant stim
-substances may be used to reduce pain or psychological discomfort
-with repeated use, removal of withdrawal is motivation
-contiguity: how soon you feel effects = more reinforcing
-often pathway of addiction is from pos reinforcement to neg reinforcement
–initial stage: drug for pos effects
–later: drug for removal of withdrawal
-increasing use separates liking and wanting
-wanting relates more to neg reinforcement
tiffany CC
drug related stim can induce cravings
Robins CC
US soldiers dependent on heroin in vietnam but rarely continued to use at home (they were out of the environment so had no cues)
wickler
-opioid withdrawal in group therapy with now drug free clients, when talking about the drug they started sniffing and yawning showing signs of withdrawal
conditioned place preference
-place initially NS
-repeated drug use in same place means this place becomes CS
siegal place preference
-gave rats large doses of heroin
-control (not addicted) were 95% likely to die
-rats who had been cond to be addicted to heroin were less likely to die
-when given dose in same environment as when addiction was cond, the rats were less likley to die
cond tolerance
Ehrman
-opioid detoxed pp given signalled or unsignalled (whether they knew it was coming) dose of hydromorphone or placebo
-greater physiological approach to drug when unsignalled
needle freaking
Levine
-heroin users when heroin not available
-go through ritual of preparing to inject but use saline or something else instead
-mild high, some physiological signs and some withdrawal reversal seen
addiction therapy based on CC
cue exposure therapy: aims to reduce cond drug effects
-based on idea of extinction, repeated non reinforced exposure to drug cues diminishes cond drug effects
(research inconclusive)
-what are the main gateway drugs
alcohol, nicotine, cannabis
gateway hypoth of drug use
-use of psychoactive drug increases probability of further drug use
-first time use of specific drugs is not random but shows trends
-use of drugs often in sequence
-other variables effecting drug use: age, gender, family, laws, mental health etc
what are the drug reward pathways in the brain
-both pathways are involved in rewarding properties of the drug
-mesolimbic pathway originates in VTA and terminates in nucleus accumbens, amygdala and hippocampus
-mesocortical pathway originates in VTA and terminates in frontal cortex
(activated by drug and non drug rewards)
DA hypoth
-original hypoth: addictive drugs release dop but non addictive drugs do not
-da release in mesolimbic and mesocortical pathway is increasingly rewarding and this action is addictive
-da findings indicate da release in certain drugs either directly or indirectly but not in others that are not addictive
reward prediction error (RPE)
diff between received and predicted rewards
-if we regularly receive a reinforcer, subjective reward can diminish (habituation)
-cond cues lead us to expect reward, reward is less than expected (rpe)
-dopamine activity presented when there is an error between reward expectant and received
RPE and cocaine
-cocaine dependent users vs non users
-dopamine signals of reward expectation similar for both groups
-signal for received reward was lower for cocaine dependent users in ventral striatum and orbitofrontal cortex bc cocaine dependent users expected the reward
