My best friend 'quit' cocaine but i can never tell the difference what does it do/ how can you identify a coke user?

Coke user: In addition to physiological effects, interpersonal/social/educational/career aspects are affected.

Multiple hints: Cocaine is a stimulant.Your friend may display sweating, overactivation, jitters, confusion, irrational thinking, paranoia, pressured speech, sleeplessness, exhaustion, weight loss, violence, impulsivity, poor concentration, elevated pulse&/or blood pressure, change of friends to druggies, change of interests, loss of libido, emotional distance, bloody nose, dysfunction overall, lack of money, crime to get drug money.