Drug Abuse Flashcards
Define drug addiction
state of intermittent or chronic intoxication resulting from repeated consumption of a drug leading to 1. overpowering desire to continue taking the drug 2. psychological and physical dependence for the drug effects 3. tendency to increase dose 4. detrimental effects on individuals
What causes drugs to be so dangerous, and causes the health risks
the problems is when trying to OBTAIN the drug
physical dependence theory of addiction
become dependent on the drug because of its withdrawal symptoms are too bad, the negative reinforcement. (the effects are too bad when stopping, so just keep taking it)
positive incentive theory of addiction
drives addiction just because the symptoms are highly rewarding and they like them, for the pleasurable effects
Robinson and Berridge argues it wasn’t the pleasure of taking the drug but the…
anticipation, people believe the drug will be highly rewarding. expectation is higher than the actual reward received
(ICSS) intracranial self-stimulation
olds and milner did this experiment
rats pressed lever to self administer an electrical stimulation to specific sites in the brain
areas of the brain that produce good ICSS are areas that mediate pleasurable effects (ex. food, sex, etc.), areas used by the dopamine system
what system is evidence for olds and milner ICSS
VTA to nucleus accumbens = activated by primary reward and post event information
Evidence for ICSS (4)
- mapping studies = sites at which ICSS occurs are part of the dopamine system which has the highest response rat and lowest thresholds
- cerebral dialysis studies = microdialysis sampled extracellular fluid and saw increased dopamine in nucleus accumbus during reward
- dopamine antagonist and agonist studies
- lesion studies - dopamine depletion
(need to make sure controlling motor deficits because dopamine is important in motor control too)
What two paradigms are mostly used when studying neural mechanisms of addiction
- drug self-administration = drug delivered to blood stream or specific brain area
- Conditioned-place preference (CPP) - two different contexts, one has addictive drug and other just has saline, animal would choose the chamber with the addictive drug
disruption of dopamine system reduced the…
rewarding effects of addictive drugs
what does self-administration of addictive drugs do to dopamine levels
it increases dopamine release
What amygdala, hippocampus, and striatum control in perspective of drug addiction
amygdala = acquires information that promotes approach and interaction with the stimuli associated with the drug
hippocampus = acquires contex and place of the drug being obtained
striatum = promotes the bad stimulus response habits, do the drug but get a reward, solidifies the S-R habit
perirhinal cortex - because lots of objects associated with drugs and the behaviour
why do drug addiction behaviours and thoughts dominate
because they are so abnormal that relate to plasticity processes and associated memories
Susceptibility model
what makes one person for susceptible than another to addiction
GDE can produce organizational changes to have more be more susceptible
3 Scenarios of the susceptibility model
- enhanced control of one system- habit dominance (increase striatum function and gets addicted faster, the habit system is dominant)
- reward value increases - creates acceleration of compulsive seeking drug behaviours (big amygdala, hippocampus, and nucleus accumbens)
- reduction of inhibitory control - making choices is compromised (prefrontal cortex decreases size and control)
