SUD neurobiology

Question 1

Addiction cycle 3 phases

Answer 1

1. Binge/intoxication (basal ganglia)
2. withdrawal/negative affect (extended amygdala)
3. preoccupation/anticipation (prefrontal cortex)

Question 2

Basal ganglia

Answer 2

Ventral tegmental area (VTA) makes DA
DA activates nucleus accumbens (NA) & dorsal striatum (DS)
- NA for motivation & reward
- DS for habits & behavior

drug acting = EXCESS DA prod.
- external stimuli can begin to be associated with drug use and bump in DA (triggers for rehab/recovery pts)

Chronic use = down reg of D2 receptors –> anhedonia (not feeling pleasure at things that used to be pleasurable)

these pts feel like a missing piece has been filled
- they feel human, real, normal

Question 3

Extended amygdala

Answer 3

*response to stress (fight v flight) & handles emotions (irritability and anxiety)

when ABSTAIN drug: corticotropin releasing factor (CRF) & dynorphine are released bc of stress

• when you + physical symptoms –> strong craving
• drug use feels life essential

giving in and using = negative reinforcement loop
(more drug is needed to overcome stress)
- SHAME SPIRAL

Question 4

Pre-Frontal Cortex

Answer 4

• decision making, organizing thoughts, regulation of action/impulse

external stimuli = glutamate release
- mid-brain excitement (survival) –> urge to use
- mid-brain SHUTS DOWN prefrontal cortex!!
(pre-frontal cortex loses ability to self-regulate)

= compromised decision making ability & inhibition in behavior