short term effects trouble sleeping, irregular heartbeat, restlessness etc. etc. can trigger panic attacks to people who are prone to them and potentially can kill children
long term are insomnia, constant anxiety (i have witnessed first hand caffeines effects on anxiety. it sucks to see), depression, stomach problems, high blood pressure, and it also has problems when used during pregnancy and breast feeding
so yeah to me its a little weird how normal caffeine is in life to where it is almost unrestricted where i live while nicotine has flavor bans