Pathways of Addiction & Dependence Flashcards
define addiction
a behavioural pattern of drug abuse characterised by overwhelming involvement with the use of a drug, the securing of its supply and relapse after a period of discontinuation
what pathway does addiction change
the mesolimbic dopamine system
true or false - drug abuse causes dopamine release from the mesolimbic system
true
describe the vicious cycle of addiction
tolerance arises over time, this requires bigger doses to achieve the same high - this continues
how do psychotropic drugs affect the mesolimbic pathway
cause dopamine to be released more explosively and pleasurably than naturally
what determines how addictive a substance is
how quickly the substance reaches the brain
what is anhedonia
the inability to experience pleasure
describe dopamine firing over the progression of stimulant abuse
initial doses of stimulants cause pleasurable phase dopamine firing (which drives reward conditioning)
this leads to craving between doses - there is some residual dopamine firing
higher and higher doses are required to reach that level of dopamine firing
the higher the high, the lower the low = dangerous drug seeking behaviour which ultimately leads to burn out
what determines addiction on the individual level (2)
impulsivity
and individuals who have a genetically dysfunctional reward system
why may the number of dopamine receptors a person has mediate their addiction
subjects who only have a few receptors = taking it does not cause an effect at first but increasing dosage = more rewards
subjects with many receptors = taking the substance will be aversive and they will not try it again
why might people with low numbers of receptors feel predisposed to trying drugs
there internal reward system is not working well - by taking drugs they are compensating for the endogenous highs
why in addicted people do they get a high by just thinking about drug use
drug = high - brain learns to associate handling the drug with a dopamine high
these cues that predict pleasure cause dopamine release in the anticipation of reward
what releases dopamine in the anticipation of drugs
nucleus accumbens
