According to the labeling theory when does primary deviance convert into secondary deviance?

Primary deviance can be converted into secondary deviance when the occasional users are to be labeled as ‘d o p e heads’, it is because a primary deviance is the stage where deviant behavior is in the initial stage whereas secondary deviance is where an individual is to be labeled as a criminal.

If an occasional user who does not always commit to a certain behavior and was labeled as a d o p e head of which is defined as doing things that are lowest to the low, they are to be called as a criminal of which falls at the secondary deviance.