exposure models of addiction Flashcards
how has drug use changed over time
it is relatively stable
what age and sex is drug use most common in
younger people
males
what does the exposure model suggest
all people are at risk of becoming addicted to drugs, given sufficient exposure, drugs interact with and change the brain, brain changes create continued motivation to use the drug
what did Bardo et al 1996 suggest about exposure models
models differ in their explanation as to what sort of changes drugs produce in the brain and what sort of motivation drives subsequent drug use
what does the exposure model suggest about withdrawal
addicts continue to use drugs in order to avoid withdrawal
how does the APA define withdrawal
refers to the physical and psychological symptoms that occur when a person reduces or stops intake of a substance that they are dependent on
these symptoms can vary widely in severity and type, often leading to cravings, anxiety and distress
what is withdrawal
the initial high exhausts the reward/pleasure regions of the brain, and once the drug wears off the user goes into withdrawal
- very aversive - a form of negative reinforcement
what are withdrawal model issues
- relapse - stopping drugs under medical supervision does not necessarily result in long term abstinence they often relapse
- can’t all be aversive - midbrain dopamine cells increase activity when humans or animals detect or consume both natural rewards and drugs of abuse - positive reinforcement
what did Wikler propose about withdrawal
- it can be triggered by external cues
- environmental stimuli, such as the addict’s bedroom or living room are consistently paired with withdrawal
- pavlovian conditioning - subsequent exposure to these cues is then sufficient to elicit withdrawal, precipitate relapse
- thus conditioned withdrawal can explain relapse following primary withdrawal
what did Obrien et al 1977 do to study conditioned with withdrawal
- took human volunteers. they experimentally induced withdrawal using an opiate blocker and they’d start to feel pretty rough
- people with opiate blocker and conditioned cue were showing higher symptoms of withdrawal
what is the opponent process of model
- initial positive experience, positively reinforcing drug use
- subsequent negative experience, where the body attempts to restore balance, leading to a negative effect
- with repeated use, the initial positive effects become weaker and the negative effects become stronger
- creates a cycle of addiction
how is tolerance explained by the opponent processing model
after repeated use of a drug, the body’s response to the substance diminishes over time. this means that higher doses of the drug are required to achieve the same effect. tolerance can develop to various effects of the drug, including it’s therapeutic effects, side effects or both
what is pharmacodynamic tolerance
this occurs when the drug’s effects at the cellular or the receptor level becomes less pronounced
what is pharmacokinetic tolerance
this arises when the body becomes more efficient at metabolising or eliminating the drug
what did Siegel 1983 say about conditioned tolerance
environmental cues associated with drug taking can elicit a drug opposite response.
- drug opposite response may be aversive, and motivate drug taking to alleviate this state
what did hogarth et al say about positive conditioning
data consistent with hypothesis drug cues prime drug taking by reminding the addict of the positive appetitive qualities of the drug
