are you *eating* the nail polish? if so, that's a bad idea. Are you *huffing* the nail polish? that's also a really bad idea.
No, the substances in nail polish are not addictive, but they are toxic when taken internally (eaten, huffed, etc.).
Here's what's in this bottle of Hot Topic signature nail polish:
butyl acetate, toluene, nitrocellulose ethyl acetate, tosylamide, formaldehyde resin, dibutyl phthalate, isopropyl alcohol, stearalkonium, hectorite, camphor, benzophenone
Al of these are organic compounds (they have carbon in them). Isopropyl alcohol is something you may have recognized -- it's rubbing alcohol. Toluene is a solvent, keeps the stuff liquid. Toluene can be carcinogenic (cancer-causing), so it is usually not included in newer nail polishes -- this stuff just happens to be of poor quality. Stearalkonium is an altered for of stearic acid -- a fatty acid found in beef fat. Formaldehyde is what they use to preserve dead specimens in jars -- it is toxic!
And the smell of nail polish is from the various aromatic compounds like benzophenone and toluene. They have a sweet, chemical-y smell to them, and because they are toxic, they can make you feel kinda funky when inhaled. That's not a high, that's killing brain cells.
So, why are you putting this on your nails? Why am I putting it on my nails? because they stuff is harmless when used properly. Apply only wth proper ventilation so the vapors don't fill the room and make you sick. don't drink the stuff. And if you bite your nails, don't deliberately lick up the paint chips, of course (I once got a panicked ICQ from a friend who forgot her nails were painted, and she bit her nails, swallowed a few falkes and was afrid she was gonna die. A few chips won't kill you, but i honestly wouldn't make a habit of it).
"Things are only fragile till they break."