It took me about a year to become a full-fledged opiate addict. It started when I was on probation for poss. of marijuana. I started doing oxys and other p/k's because they don't stay in your piss very long. The worst long term effect of opiate addiction is Anhedonia. I got clean for 3 years and the anhedonia never cleared. You lose your passion for life. You lose interest in living.
When your body gets used to you ingesting synthetic opioids, it stops making its own (endorphines, dopamine, neuro-epinephren, serotonin, ect). When some people stop, like me, their brains never start producing those chemicals on their own. I won't tell you how to live your life, but atleast educate yourself to minimize your risks.