Main Entry: cult
Pronunciation: 'k&lt
Function: noun
Usage: often attributive
Etymology: French & Latin; French culte, from Latin cultus care, adoration, from colere to cultivate -- more at WHEEL
1 : formal religious veneration : WORSHIP
2 : a system of religious beliefs and ritual; also : its body of adherents

from this defination almost any religion could be defined as being a "cult". AA/NA however is not a religion or a system of religious beliefs so therefore can not be a cult. There are plenty of non religious people that go to these groups.