Lecture 16: Addictive disorders: substance use Flashcards
Concept of addiction
- addiction= primary chronic disease of brain reward, motivation, mem + related circuitry, with potential for both relapse + recovery
- physical + paychological dependence: adaptation resulting in tolerance + withdrawal, urges
- reward seeking beh has become out of control– keep doing it despite negative consequences
- common components of addiction
- salience–> nothing else helps
- mood modification
- tolerance–> increase dose
- withdrawal–> to eliminate withdrawal symptoms
- conflict
- relapse
Brain disease?? vs psychosocial factors
- blame addiction as brain disease
- social factors don’t play important role
- “my brain made me do it”
what is dominant theoretical framework in addiction science
biopsychosocial framework
what is multifactorial interaction between biopsychosocial factors
bio, social, psycho
- syndrome (signs + symptoms), rather than unitary disorder
how does addiction lead to motivational shifts
- anxiety, depression, low self-esteem= drinking
- genetic / neurobiological + env (poverty, lifestyle, trauma exposure)= drugs, smoking
what are addiction models of beh
- medical model
- rational choice model
what is medical model
no control over cravings
+ reduced stigma, blame
- reduced personal responsibility, trust in beh (can relapse)
what is rational choice model
characterised by voluntary beh under control
+ increased personal responsibility
+ increased sense of control
- majority don’t want treatment
which reward systems are affected by drugs
- dopaminergic system
2. endogenous opioid system
how does dopamine work (from drugs)?
- concentrations of dop. increase (directly or indirectly) due to most drugs
- ex. alcohol, nicotine, weed, opioids, coke
- dopamine in cell body
- conveyed down axon
- released in terminal
- stimulates receptors
water as dopamine ex.
- drugs= act like rubber stopper
- molecules block dopamine transporter
- stops reuptake of dopamine into neurons
= excess of dopamine in synapse + overflow of dopamine= pleasure
explain opponent process theory of addiction
Experienced state:
- feel pleasure–> feel unpleasant
- addictive stage: build tolerance, so not that pleasurable= thats why increased unpleasance
Opponent process:
- happy for some time–> little sad
- addictive stage: happy for some time= really sad (hedonic contrast)
tolerance in substance dependence
homeostatic state: opponent-process (b process) balances drug activation (a process)–> can return to homeostatic state
- after repeated exposure to drug= affective system transitions to lower allostatic level– cause you build tolerance
- not that much pleasure and more sad
I-RISA (Goldstein + Volkow)
- drug addiction= mediated by changes in circuits modulated by dopamine: mesolimbic and mesocortical
what is mesolimbic
mesolimbic: amygdala, nucleus accumbens, hippocampus
- acute reinforcing effects
- mem + conditioning linked to craving
- emotional + motivational changes during withdrawal
what is mesocortical
prefrontal cortex, orbito-frontal cortex, anterior cingulate
- conscious exp of intoxication, salience, expectations, cravings, decision-making
what are the 4 clusters of behs involved?
- intoxication / excitement
- craving
- compulsive use
- withdrawal
ex. eating piece of cake: take a bite–> releases dopamine to all regions
Amygdala: this is yum, makes me happy rn
Hippo: remembers experience + context
Prefrontal cortex: focus attention on cake
Nucleus accumbens: pleasure center stimualted= makes you wanna take another bite
Reward system: reactivated w/ each bite
explain addiction as choice?
- medical model focuses on impaired control
- rationality: subjective short term benefits outweigh long term costs (ex. smoke now feels good but long run cancer)
importance of effective treatment
- no single treatment is sufficient
- treatment available + accessible
- address multiple psychological, medcial, social interventions
- comorbid conditions– try to include this too
- instructed treatment–> effective change
intoxication / excitement
- higher extra-cellular dop concentrations in limbic
circuits (nucleus accumbens) + frontal lobe
craving
- classical + operant association of cues w/ pleasure
- mem consolidated in amygdala + hippo (thalamo-
orbitofrontal circuit for craving)
withdrawal
- dysphoria, irritability–> relapse
- involvement of frontal cortical circuits
compulsive use
- still do it, even if no longer perceived as pleasurable
which is more likely to relapse: medical model or rational choice model?
medical model= since low self responsibility= blame it on the fact that you can’t control it
