Chapter 5 (L7)

Addiction

preoccupation with a drug that is compulsive despite harm

Tolerance

The brain adapts to the same dosage, while increasing the risks for overdose

Withdrawal

Symptoms that are the opposite of drug’s effects, occurs as the brain adapts without the drug

Depressants

Reduce CNS activity, creating a sedative, anxiolytic, and hypnotic effect

How do alcohol, barbiturates, and Benzodiazepines work in the brain

Enhances GABA and suppresses glutamate, creating a sedation effect

The GABA-A receptor

Five-part complex with a binding site for GABA, barbiturates, and benzodiazepines; causes extreme risk when multiple are used at once

What are the three main depressants

alcohol, barbiturates, and Benzodiazepines

Stimulants

Increase CNS activity, causing arousal, alertness, and elevated mood

What are the three main stimulants

Cocaine, amphetamines, and nicotine

how do stimulants work in the brain (cocaine, amphetamines, and nicotine)

Cocaine: Blocks the reuptake of dopamine and serotonin, prolonging their effect at the synapse; Amphetamines: Both increases release and blocks reuptake, creating a bigger flood from multiple directions; Nicotine: Triggers dopamine release in the nucleus accubens to a different route

Opioids

Mimic endorphnines, causing euphoria but also causes respiratory depression, which is the mechanism behind overdose

What are the 3 main opioids

OxyContin, fentanyl, and heroin

What is heroin so problematic

It’s lipid solubility lets it cross the blood-brain barrier, which makes its effects much quicker and more addicting

Psychedelics

Distort perception rather than creating it; most act on serotonin rceptors

What are the three main psychedelics

LSD, MDMA, and THC

MDMA

Blocks reuptake of serotonin, dopamine, and norepinephrine

THC

act on the brain’s own cannabinoid receptors, controversial on how addictive it is because of mild withdrawal symptoms

Cannabinoid receptors

Dense in the frontal, hippocampus, and cerebellum, which is what ultimately causes marihuanas psychedelic effects

The mesolimbic Pathway

Dopamine neurons run from the ventral tegmental area to the nucleus accumbens; With every abused drug, this pathway converges with the procress, causing dopamine to rise and triggering the reward system

structural changes to brain with drug abuse

More dendrites and synaptic complexities in the nucleus accumbens and prefrontal cortex ultimately drop dopamine activity, decreasing pleasure for normal things in life

Hypo frontality

Reduced activity in frontal regions that normally support impulse control and behavioral inhibition

Cue triggered cravings

Environmental cues that are reinforced through drug use, creating a normality associated with the environment and drug; can persist years after withdrawls symptoms leave

Agonist treatment

Replace the drug with a safer version of itself (Vapes to nicotine patches/gum)

Antagonist treatment

block the drugs effects at the receptors (ex: naloxone)

Naloxone

The emergency overdose reversal that is commonly required in schools and public places

Aversive treatment

Make the drug unpleasant (ex: antabuse paired with alcohol causes rapid sickness)

agonist drug

mimics or enhances the effect of a neurotransmitter

Antagonist drug

blocks a transmitter from binding

conditioned tolerance

tolerance that is tied to the place or circumstance one usually is in