countermeasure

adversity

purpose

countermeasure

neurotransmitter

regulator

comforter

hardship

maintain durability

endorphins

dopamine antagonist

hyperactivity

danger

maintain existence

adrenaline

serotonin agonist

phobia

unfamiliarity-uncertainty

maintain tradition

adrenaline-glutamate

serotonin-GABA agonist