drugs Flashcards
addiction theories
state that addiction seems to come from a combination of physical dependence & the expectation of pleasurable effects
physical dependence theories
states that addiction is a vicious cycle of drug use and withdrawal symptoms
- physical dependence causes a strong craving for the drug
criticism: people who have been treated for addiction still relapse
drugs like cocaine don’t produce huge withdrawal symptoms but are highly addictive
positive incentive theories
state that drug use is stimulated by expectation of pos effects
the user expects the same pos effect with every intake but drugs dont always have the same effect = they take more to achieve the pos feeling
explain diff in positive incentive value (the expected pleasure after intake) & the hedonic value (the actual pleasure experienced after intake)
cross tolerance
when tolerance to one drug occurs and causes tolerance to a similar drug
drug sensitization
an increased sensitivity to some effects of a drug
tolerance may occur from some effects while sensitization occurs for others
metabolic tolerance
comes from a reduced number of drugs reaching certain areas of the body
drugs are broken down faster = cannot reach the receptors
functional tolerance
comes from decreased sensitivity of specific points in the body to a particular drug
may be because exposure reduces the number of receptors that the drug can bind to
contingent drug tolerance
tolerance to drugs only occurs for the effects of drugs that one has experienced before
basically opposite of cross tolerance
conditioned drug tolerance
tolerance is greatest in situation where a drug has been taken before
e.g. u do cocaine every time at certain club so u have a tolerance but when u do it alone at home there is less tolerance
taking the drug in a diff situation can cause OD
effects drugs have on synapses
the can:
- influence the production of a NT
- trigger the release of a NT
- bind to the postsynaptic receptors & stimulate/block the receptors
- influence the reuptake of a NT
- block the reuptake = no signal is sent
- influence the breakdown of a NT
agonists vs antagonists
agonists = drugs that facilitate the effects of a NT - makes it more likely to fire by imitating the NT & binding to receptors on postsynaptic membrane
antagonists = drugs that inhibit the effects of a NT - makes it less likely to fire by blocking receptors on postsynaptic membrane
affinity vs efficacy
affinity = when a drug bind to a receptor - can be weak or strong
efficacy = when a drug activates a receptor
nicotine
nic receptors are abundant in neurons that release dopamine in the nucleus accumbens (imp in amplification of feelings & activated when thinking of something pleasant)
= nic intake causes increase in dopamine in the NA
repeated nic consumption = receptors in NA become more sensitive to nic = respond less well to other reinforcement
can lead to smoker’s syndrome & Buerger’s disease
alcohol
reaches many parts of the body bcuz the molecule are small & soluble in water & fat
at low doses: affects GABA receptors in amygdala = reduces feeling of anxiety & increases confidence
at high doses: inhibits glutamate receptors = reduces neural effects which can cause weakening of muscles
stimulates GABA receptors = inhibition of dopamine
can cause Korsakoff’s syndrome
marijuana
has a psychoactive affect due to THC
inhibits glutamate & GABA = stimulates the release of dopamine
has no receptors in the medulla = excessive use in not life-threatening
