The cognitive neuroscience of addiction Flashcards
What percentage of alcohol users meet the criteria for alcohol use disorder?
6%
What does cocaine reduce the volume of?
the inferior portion of the frontal lobe
Heroin use is associated wiht a broad range of what?
neuropathologies
What is alcoholism strongly linked to?
the Wernicke-Korsakoff syndome
What is Wernicke encephalopathy
general brain shrinkage
What is Korsakoff syndrome?
chronic “end stage” of brain shrinkage. It is a psychiatric diagnosis characterized by anterograde amnesia (inability to remember new things), which can sometimes be treated with thiamine supplements
What is anterograde amnesia
inability to remember new things
In cannabis. where was brain volume reduced in users?
in the hippocampus and the amygdala
How much risk is there with heavy canabis use?
double the risk of psychotic symptoms
What percentage of indiviudals who use drugs of abuse become addicted
10-20%
WHat is the genetic contribution to addiction?
50%
What are the 4 causal factors of drug addiction?
- Effects of drug-related cues – cue reactivity
- Effects of drug tolerance and withdrawal
- The drugs’ influence on processing of rewards (pleasure and incentives (motivation)
- Drug taking as self-medication in mental illness
What is the instrumental conditioning paradigm>
the drug is the reinforcer which strengthens the associations between drug-related cues and drug use
What is extensively documented in rehabilitation?
context-driven relapse
What did Subkov and Zilov research
Conditioned compensatory response- dogs developing a tolerance to adrenaline
What is conditioned compensatory response a form of?
classical (pavlovian) conditioning
Where does Morphine suppress activity?
in the CNS
What does repeated use of a drug lead to?
conditioned compensatory response
When does alcohol have a stronger effect?
when it is consumed as part of exotic drinks and cocktails than when it is part of familiar drinks …because the change in taste reduces the conditioned compensatory response or with new people
What is conditioned compensatory response a form of?
tolerance
What is tolerance to alcohol based on?
the desensitisation of GABA receptors where alcohol is an agonist
How does an organism prevent inhibition?
the organism compensates by reducing the sensitivity of GABA receptors in inhibitory synapses and by increasing activity in excitatory synapses
Where does pleasure show increased activation?
basal ganglia, especially in the nucleus accumbens
What is the anhedonia hypothesis?
dopaminergic synapses convey ‘goodness’ (e.g. in the above experiment, they conveyed to food its ‘goodness’)
• Dopamine antagonists such as pimozide reduce this effect, thus reducing the animal’s propensity to work for food
What was found about rats pressing a lever for drugs?
• However, when the animals had to press the lever, only the healthy rats were willing to work for it, whereas the rats with impaired dopamine transmission were happy to settle for the less tasty food
What is the incentive salience treatment?
that dopaminergic circuit involving NA and VTA is not so much responsible for the pleasure obtained from a drug, but for the motivation to obtain it
What did McKee find?
Stress decreased the delay to initiate smoking in the abstinence incentive task
