Some highlights from the National Academy Study of Cannabis:
The evidence reviewed by the committee suggests that smoking cannabis on a regular basis is associated with more frequent chronic bronchitis episodes and worse respiratory symptoms, such as chronic cough and phlegm production, but quitting cannabis smoking is likely to reduce these conditions. The committee stated that it is unclear whether cannabis use is associated with certain respiratory diseases, including chronic obstructive pulmonary disease, asthma, or worsened lung function.
There is a lack of data on the effects of cannabis or cannabinoid-based therapeutics on the human immune system, as well as insufficient data to draw overarching conclusions concerning the effects of cannabis smoke or cannabinoids on immune competence, the committee stated. There is also insufficient evidence to support or refute a statistical association between cannabis or cannabinoid use and adverse effects on immune status in individuals with HIV. Nevertheless, limited evidence suggests that regular exposure to cannabis smoke may have anti-inflammatory activity.
The evidence reviewed by the committee suggests that cannabis use is likely to increase the risk of developing schizophrenia, other psychoses, and social anxiety disorders, and to a lesser extent depression. Alternatively, in individuals with schizophrenia and other psychoses, a history of cannabis use may be linked to better performance on learning and memory tasks. Heavy cannabis users are more likely to report thoughts of suicide than non-users, and in individuals with bipolar disorder, near-daily cannabis users show increased symptoms of the disorder than non-users.
Problem Cannabis Use
The evidence reviewed by the committee suggests that with greater frequency of cannabis use, there is an increased likelihood of developing problem cannabis use. There is also evidence to suggest that initiating cannabis use at a younger age increases the likelihood of developing problem cannabis use.
Cannabis Use and the Abuse of Other Substances
The committee found limited evidence that cannabis use increases the rate of initiating other drug use, primarily the use of tobacco. However, the committee found moderate evidence to suggest that there is a link between cannabis use and the development of substance dependence and/or a substance abuse disorder for substances including alcohol, tobacco, and other illicit drugs.
The committee found that learning, memory, and attention are impaired after immediate cannabis use. Limited evidence suggests that there are impairments in cognitive domains of learning, memory, and attention in individuals who have stopped smoking cannabis. In addition, there is limited evidence to suggest that cannabis use is related to impairments in subsequent academic achievement and education as well as social relationships and social roles. Adolescence and young adulthood are when most youth begin to experiment with substances of abuse, including cannabis, and it is during these periods that the neural layers that underlie the development of cognition are most active. The committee also found limited evidence of an association between cannabis use and increased rates of unemployment and low income. warm wearing for bride if the wedding hold in winter