Addiction/Tolerance/Withdrawal Flashcards
define tolerance
a need for increased amount of a substance to achieve intoxication or effect
diminished effect with same amount of the substance
define withdrawal
symptoms that occur when you stop taking the drug
make you want to take the drug again
criteria for addiction
substance taken in larger amounts/longer period of time
unsuccessful efforts to control use
greater time spent trying to obtain substance
less time doing other enjoyed activities
continued use despite negative consequences
definition of addiction
continued use despite knowledge of problems caused by substance taking
manual for assessing addiction
DSM-5
DSM-5
diagnostic and statistical manual for mental disorders
came out in 70s –> been updated –> still not perfect
criteria to diagnose people with mental health problems
effect of addiciton on dopamine levels
elevated levels of dopamine
molecular effects of short-term drug exposure
increased firing frequency and neurotransmitter release
long term drug exposure leads to ..
tolerance
effect of tolerance on receptors
receptors become desensitised and down-regulated
down-regulation of receptors
will be removed from post-synaptic membrane and may be destroyed
effect of tolerance on drug dose
much more drug required to amount same effect
effect of tolerance on effect of drug response
tolerance to drug results in lower maximal response
effect of downregulation on activity level
activity level is below normal
kindling mechanism
concept that once a suppressant is removed there is rebound excitation
may immediately cause a problem e.g. seizure
excess activity still there
effects of cocaine binge
phase 1-3
anxiety, craving, exhaustion
conditioned cues
likely to relapse at 4-6 weeks
negative reinforcement
pre-emptive drug use to terminate symptoms of withdrawal
abraham winkler
abstinence –> withdrawal –> relapse
conditioned withdrawal
withdrawal response can be exacerbated or evoked by environmental cues
e.g. come home from care all good then withdrawal caused by home cues –> David’s story
evidence for conditioned withdrawal in humans
opiate users in us achieve abstinence by taking methadone
saline or naloxone injected and learn to associate with environment
experience withdrawal from naloxone when expose to cues even with just saline
relapse typically evoked by cues associated with …
drug-use rather than cues associated with drug-withdrawal
what allows drug-use and withdrawal to intercalate
homeostasis
what explains the homeostasis link to drug addiction
opponent process theory
what is the opponent process?
homeostasis opposes the effect of the drug because it wants the body to remain in the same state
compensatory response
subkov and zilov
inject dogs with adrenaline
conditioned withdrawal
lower heart rate in absence of adrenaline
example of conditioned compensatory response in humans
davids story
developed compensatory response to morphine (sedatory drug)
required more and more in same environment
tolerance –> desensitisation/downregulation
contextual environmental cues absent, standard does way too high –> overdose
engagement in treatment can have negative effects
acute damage due to withdrawal
only partially address the cues (basis of relapse) –> cues evoke withdrawal experience
contextual cues create compensatory responses, experience different environment
define negative reinforcement
strengthening of a behaviour e.g. taking more drugs to prevent/avoid a negative outcome e.g. withdrawal symptoms
when does the kindling effect occur
after repeated attempts at withdrawal
oversensitivity of cns to withdrawal
nicotine as example of opponent process theory
take nicotine
feel good
homeostatic response –> -ve feeling
over time opponent process strengthened –> crave nicotine
initial positive response constant
—> tolerance
increased amount of drug needed to induce positive effect
describe the naxolone test on humans
tests conditioned withdrawal
test opiate users on methadone
baseline - injected with saline with no cue
learning phase - injected with naxolone (opioid-blocker) with olfactory cue e.g. peppermint –> make association between withdrawal symptoms and smell
test phase - inject saline with same olfactory smell
result - patients experience withdrawal symptoms
kindling effect on alcohol withdrawal treatment
even patients experiencing mild withdrawal should be treated aggressively to prevent in severity of subsequent withdrawal episodes
