associated with the disorder. The data is inconclusive on its existence and more research is required to establish the effect of marijuana on motivation; 5.35. Effects on memory - For a long time researchers believed that the primary effect of marijuana on memory was acute, but recent studies have reflected that in adults, damage to memory may not be permanent.121 5.36. Respiratory System - There are clearly adverse medical consequences associated with cannabis/ marijuana when smoked, as opposed to its use in other preparatory forms. While there is evidence that supports Medical Marijuana for asthma and related respiratory diseases, it is evident that these dissipate if the plant is smoked, as opposed to other uses. Participants in the Consultations and focus groups told us, however, that the preparation for asthma is not smoking, but various forms of tinctures, often using the root and parts of the plant. Marijuana, when smoked, contains more carbon monoxide, tar and cancer causing chemicals compared to cigarettes. (Moir, et al., 2008; Benson & Bentley, 1995; Tashkin et al., 1991; Wu et al., 1988; Addiction Research Foundation, 1980). Long-term marijuana smoking is associated with an increased risk of some respiratory problems (cough and sputum production) similar to that of tobacco smoking and increasing risks for lung cancer.122 It is inconclusive as to whether smoking marijuana use may cause asthma or worsened lung cancer (NAP, 2017). 5.37. Cardiovascular System - The evidence is inconclusive as to whether marijuana is associated with heart attack, stroke and diabetes (National Academies of Science Press, 2017). 5.38. Pregnancy and Pregnancy Outcomes - Studies on the effects on pregnancy and pregnancy outcome have yielded conflicting results. Some studies suggest that marijuana may be associated with increased risk of congenital malformation, foetal death and low birth weight in infants (Addiction Research Foundation, 1980). The most conclusive evidence overall support low birth weight infants but the evidence to support complications in pregnancy is limited (National Academies of Science Press, 2017). 5.39. Immune Function - Despite earlier assertions that marijuana use reduces immune function (Addiction Research Foundation, 1980), a recent review found that there is insufficient evidence to suggest that marijuana has a significant negative effects on the immune system (National Academies Press, 2017).
The Gateway Theory
5.40. The Gateway theory suggests that cannabis/marijuana use leads to the use of harder drugs. This theory has been debunked as this has not been observed in the majority of persons who use marijuana. 123
Problems with Psychomotor Functioning
5.41. Most significant from a public health perspective is the impact of cannabis use on the skills necessary for safe driving and the substantial increase of risk of motor‐vehicle accidents. There is substantial evidence that marijuana use does have an adverse effect on driving ability and increased risk of motor vehicle accidents due to the effect on cognitive processes, (reaction time, judgement, perception of sensory stimuli and of time).124 However, some studies suggest that driving risk may not be as severe as previously considered (Sewell, Poling, Sofuoglu, 2009). 5.42. In Ontario, an estimated 9% of licensed drivers aged 18 to 29 report having driven within an hour of using cannabis in the past year. In Colorado, marijuana-related traffic deaths doubled from 55 deaths in 2013 to 123 deaths in 2016.125 “Although the accident risk associated with cannabis‐impaired driving is significantly lower than that of alcohol‐impaired driving, it is a serious concern:”126
Mohini Ranganathan & Deepak Cyril D’Souza). Ranganathan and D’Souza [1] found in their review that acute administration of Marijuana impairs immediate and delayed free recall of information, while Fletcher and Honey [2] also cited evidence for difficulties in performing certain cognitive tasks. 122 (Mehra et al, 2006; Tashkin, 2013). Howden & Naughton (2011). 123 SAMHSA (2014); De Angelo (2016); (Moral et al 2003). 124 Asbridge et al., 2012; Addiction Research Foundation, 1980). 125 RMHIDTA (2017) 126 CNMH Report, 121
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