There is a general misconception is that NA is all about narcotics.
Although it is true that people come there to get help with addiction to drugs, the truth is NA really is not as much about the drugs as it is dealing with the disease of addiction. When first formed the name Addiction Anonymous (AA), was suggested BUT since AA was already taken with another 12 step fellowship using AA. As a result, the name NA was born.
Wikipedia goes deeper into it, feel free to explore it for no other reason than to get more understanding about NA.