2014). Cities with comparatively high levels of medical cannabis availability showed a frequent CU pattern. Likewise, Mair et al., (2015) found that the density of local cannabis dispensaries was positively associated with an increase in CU-related hospitalizations. Moreover, cannabis potency detected in confiscated samples increased steadily from about 3% in the 1980s to 12% in 2012 (Volkow et al., 2014). Preliminary data suggested that the average potency of cannabis seized by law enforcement increased by a half percentage point on average after medical cannabis legalization (Sevigny et al., 2014). The increase in the THC content raises concerns that potential adverse effects of problem CU, such as addiction, motor-vehicle accidents, or psychotic symptoms, may be intensified (Freeman and Winstock, 2015; Monte et al., 2015).
