Most commonly snorted in 'lines'. Yes, very much so. Cocaine causes an unmistakable euphoria and sense of well-being that is the basis of addiction. Cocaine is much more addictive when smoked or injected because the rush and the peak occurs much quicker than when snorted.
Cocaine effects all the monoamine neurotransmitters.
For example, in preparing for physical activity, it would be better if your body were attempting to lose excess heat instead of gaining temperature. This is why the excessive use of cocaine can be so dangerous physically. The system of turning 'off' neurotransmission once it is started by the release of neurotransmitters is tampered with. Cocaine prevents this process from working properly. The result is that norepinephrine, dopamine, and serotonin all stay in the synapse much longer once released.