A small number of studies have looked into the concept of cannabis dependence, comparing frequent (1) or daily cannabis users with and without dependence (Looby and Earleywine, 2007; van der Pol et al., 2013), or populations with self-perceived treatment need to populations without this perception (Copeland et al., 2001). Depending on the population studied, somewhere between 25% and 50% of daily cannabis users will fulfil the criteria for dependence (NIDA, 2012). A general conclusion that can be drawn from these studies is that, while frequent to daily use of cannabis is a strong predictor of cannabis-related problems (Fischer et al., 2011), these accumulate even more in users with (probable) dependence.

Although the above-mentioned studies have found relatively small differences in the frequency or intensity of use or quantity of cannabis used between dependent and non-dependent frequent or daily users, marked differences were identified between dependent and non-dependent users in the levels of cannabis-related problems experienced, use of other substances and mental health problems. Other characteristics more prevalent in dependent users included solitary use and use in order to cope with problems.