Crack detox symptoms start within a few hours after the last use, and can last for weeks and even months on end. What is crack detoxification like? Can you detox from crack cocaine safely? More, here.
Yes, you can get addicted to crack. In fact, crack is HIGHLY addictive as a result of euphoric effect and short half-life. More on the addictive properties of crack here.
Dependence on crack cocaine occurs after regular, daily use and can manifest in a series of symptoms when you stop using crack. More on the signs of crack dependence and its treatment here.