Speaking from personal experience and currently being in the recovery community (have been in/out of recovery for last 20 yrs)... I can offer the following
IMO very few people will or can use cocaine recreationally. And addiction has very little if anything at all to do with frequency of use. Cocaine is one of the most and most quickly addictive drugs. IE. very easy to become addictive and very quickly often from first time used.
It most definably will change one's personality/character.
Among other reasons it becomes addictive and changes people are medical.
I am sure you know what are endorphins. Endorphins are created by our bodies naturally. They relieve both physical and emotional pain. Believe it or not we are all almost always experiencing pain all the time that being kept in balance by endorphins our bodies are creating and releasing into our systems. The endorphins are captured by endorphin receptors. Cocaine what it does is overwhelm the endorphin receptors with far too much chemical endorphins... causing an euphoric state. IE get real high. When the body senses that the receptors are over loaded it will stop manufacturing natural endorphins. Therefore when the cocaine is no longer there and there is no more natural endorphins to take it's place... now the receptors are completely empty... hence very deep depression ... and other pain. Hence being irritable etc. It may takes days even weeks before the body will start to naturally manufacture endorphins again. Thus the cause of PAWS. (google - post acute withdrawal symptoms)
One of the very first symptoms of addiction is denial. Often not only is the addict in denial so are family and friends.
Addiction IMO (and most in the medical community) is treatable however not curable. Only
complete abstinence can relieve the symptoms. Even after a long period of complete abstinence if one
picks up again... the vicious cycle will begin all over again very quickly if not immediately.
Ask your friend to answer the 20 questions (link below) as honestly as possible. If the answers cause your friend some concern then they should seek help. Your friend must realize they need help on their own... w/some loving guidance. You cannot lecture an addict. If you are too aggressive and try to force it on them... or start breathing down their necks they will fight you tooth and nail and retreat into their addication even more. It's a bit of a tough balance cause you need to offer them some tough love with some understanding and acceptance. Sort of like your kids you know... you love them no matter what... but you not gonna take their chit... know what I mean?
http://www.ca-on.org/addiction_test.html
At the bottom of this test it says if one answers any yes them maybe there is a prob. IMO if one asnwers three yes the for sure there is a problem.
I will be more then happy to meet up and take your friend and yourself if you like to a CA meeting to meet some others who can offer some input or at least give some food for thought.
Peace and Love. TheNiteHwk.