yes, it is possible. let me tell you my story and i promise, ill be as breif as possible.
my dad was in the navy and spent years on the ships. when he became a civilian, he had trouble sleeping because it was too quiet and he was use to loud ship engine noise. his doctor finally put him on seginol(sp?) to help him sleep. naturally, he became addicted to that. he popped them when he woke up, popped them all day to feel good and popped them to go to sleep. his doctor was arrested and sent away so dad had to find a new source.
my grandmother (his mother in law) had a subscription to the stuff so he was getting his stuff from her. he was so addicted that we went to her place out of town every month carrying a new appliance for her so that he could keep his supply going. she was buying so much of it, that her doctor took her off of it, because the doc become concerned. dad had been on seginol(sp?) for about 7 years.
dad had a high profile job so he couldnt go out on the street to get the stuff and he couldnft find any other doctors that were sympathic to his cause. my dad had no other source, so he started taking nyquil as a substitute. he drank it when he woke up, buzzed on it all day, and took it when he went to sleep. he was on nyquil till about 1980 when he was diagnosed with terminal cancer (mesothelomia). he had been on nyquil for about 5 years.
one of my houshold chores was that i was in charge of the nyquil bottle disposal. im talking about the largest bottles available. we used to have 2 trash containers in the house and 2 trash cans in the alley for trash pick up. one for household garbage and one for empty nyquil bottles.
sometimes, the nyquil container would fill up too fast, and i would have that nyquil bag on standby waiting for trashday so i could move them out.
the irony of this was, my dad was strictly against alchohal of any kind and drugs of any kind. he would have killed me on the spot if i got within ten miles of anything.
YES, you can be addicted to nyquil, i sincerely beg you to please consider looking at this seriously, and take care John, Pensacola, Florida