While gateways and reverse gateways have traditionally referred to substance initiation, there is also overwhelming support for associations between cannabis use and escalation of tobacco involvement. In the study by Patton and colleagues (22), daily cannabis use was associated with a 3.6-fold increase in nicotine dependence. In data from the U.S., past month cannabis use was associated with a more rapid transition into daily smoking and nicotine dependence (25) (26).
