substance abuse Flashcards
schedule I
no accepted medical use
- high potential for abuse
schedule II
high potential for abuse which may lead to severe dependence
schedule III
less potential for abuse
- may lead to moderate/ low physical or high psychological dependence
schedule IV
low potential for abuse
- relative to substances in schedule III
schedule V
low potential for abuse
- relative schedule IV
- contains limited quantities of certain opiates
what makes substances addictive?
- positive reinforcers: euphoria
- negative reinforcers: avoiding aversive symptoms
positive reinforcers
- strong reinforcement increases “work” threshold and likelihood of continued use
breaking point
point at which the work is too much for a given reward
negative reinforcement
- primary motivation is to alleviate the negative affect of withdrawal
- cycle is just as powerful as seeking out drugs for their rewards
impulsive stage
binge intoxication -> pleasurable effects -> abstinence -> reward craving
compulsive stage
prolonged intoxication -> relief -> protracted abstinence -> relief craving
cycles of addiction
- binge intoxication - characterized by impulsivity
- withdrawal/ negative affect
- preoccupation/ anticipation
mesocorticolimbic dopamine
- dopaminergic system plays a central role in reward and reinforcement
- amygdala: emotional factors of drug use
- hippocampus : CPP, anticipation, relapse and memory
PFC region CA1: plans use, inhibits counteractive efforts
medial forebrain bundle
a collection of ascending and descending pathways that carries info from the VTA to the NAc and back
nucleus accumbens
responsible for pleasure/ euphoria and critical to the development of addiction
major NAc inputs
- prefrontal association areas
- basolateral amygdala
- ventral tegmental area
- CA1 region of hippocampus
major NAc outputs
- basal ganglia, ventral globus
- VTA, substantia nigra, reticular formation
NAc shell
- extended amygdala
- inputs from BLA and ventral subiculum
NAc core
inputs from BLA and para-hippocampal regions
prefrontal cortex
- synthesizes and coordinates information as it relates to drug use
- involved in planning for drug use
- involved in inhibiting behaviors that counteract drug
use
neuroadaptation example
decreased activity of reward circuit occurs during the transition from binge/intoxication to negative affect/withdrawal
within- systems adaptions
- direct attempt by the brain to counteract the repeated
drug-induced activation of that circuit - cells will start pulling receptors from the membrane,
releasing retroactive transmitters to slow neurotransmitter
release
between systems adaptations
- gradual recruitment of the anti-reward system
- neuroanatomical make up of the anti-reward system is the
extended amygdala (i.e. bed nucleus of the stria terminalis,
central nucleus of the amygdala, nucleus accumbens shell) - norepinephrine, corticotropin-releasing factor (CRF) and
dynorphin are the main transmitters involved in this
system; - this system is in place to inhibit the reward
system and mediate aversive effects of stress
opponent process model
- any stimulus that provokes a
strong affective reaction
(pleasure or discomfort),
automatically sets in motion
an opposing affective
response that is experienced
after the initial stimulus
ends - allostatic changes gradually
shift the hedonic setpoint
preoccupation/ anticipation
dysregulation of the prefrontal cortex
Process:
- thalamus relays drug-induced stimuli to the insula (interoceptive & external stimuli)
- insula mediates the conscious awareness of these
stimuli
- projections from insula to ventro-medial prefrontal
cortex and amygdala (modulated by dopamine from
VTA), transform the interoceptive information into
feelings of pleasure and desire for the drug
