Apart from the current evidence that suggests both short- and long-term risks in psychiatric illness, cannabis involves other adverse effects that must not be overlooked. Cognition can be impaired with both acute use of cannabis as well as overtime in chronic users. This includes impaired short-term memory, motor coordination and control, executive functioning, as well as altered judgement [12, 28, 103, 136]. These deficits can put individuals at higher risk for injury and disease, for example, from motor vehicle accidents due to impaired motor control or from sexually transmitted disease due to impaired judgement in sexual encounters [149]. Additionally, short-term cannabis use, if consumed at high doses and with high THC potency, can induce paranoia and even psychosis, as described in the ‘schizophrenia’ section [31, 149]. With respect to long-term effects, a major risk involved with cannabis use is addiction; roughly 8.9% of individuals who use cannabis develop an addiction following lifetime exposure [95]. Moreover, almost half of chronic users experience robust withdrawal symptoms after cessation, which can include characteristics that range from sleep problems and nightmares to dysphoria and
