drugs & neurotransmitters

substances

• addiction = psychological disorder

• substances are drugs that effect the brain, body, and behaviour

• substances include — alc, caffeine, cannabis, hallucinogens, inhalants, opioids, sedatives, stimulants, tobacco, etc.

why is a substance addictive

• activates the brain’s reward system (in)directly (reward system important for survival)

• dopamine (neurotransmitter) released when needs are met

• tegmental area (VTA) releases dopamine to several other parts of the brain like:

  • amygdala: sensing & expressing emotions

  • nucleus accumbens: motor control

  • hippocampus: memory

  • prefrontal cortex: planning & attention

• cells that fire together wire together

• strengthens the connection so that it’s easier to fire together again in the future

causes of substance disorders

• genetics: 40-60% of vulnerability of developing one is

• environmental: accessibility, family members, friends/peers with addictions

• developmental: ppl using drugs before/during adolescence have higher risk of addiction

reuptake inhibitors

• they block transporters so neurotransmitters stay in the synapse longer

  • activates receptors longer than normal

• eg SSRI

agonists

• imitate neurotransmitters, cause the same action as the substance (same response as natural neurotransmitter)

• use the same receptors as neurotransmitters

• eg. fentanyl binds to opioid receptors

antagonists

• blocks/reduces the effect of neurotransmitters

• eg. naloxone blocks opioid receptors, can reverse opioid OD