A substantial survey of the up to date medical research on the harmful effects of cannabis has recently been published. Key points are-
Cannabis use causes acute heart and cardiovascular problems including heart attacks, angina, stroke, artery hardening, blood clots and reduced oxygen levels in blood.
The immune system is suppressed causing increased risk of infection and tumors, also reduced antibody production and blood cell count.
Cannabis use brings on depression, aggression, violence and suicide.
Skills are impaired by cannabis use and are critical for passenger vehicle pilots and drivers likely to lead to fatal accidents.
Cannabis use leads to cancer with far higher risk factors than tobacco particularly for lung cancer and cancer in the respiratory system.
Cannabis is addictive, is hard to stop using and leads onto other illicit drug use.
Cannabis adversely affects human reproduction, pregnancy and fetal development.
Cannabis use causes brain damage, reduces cognitive function, adversely changes personality and decreases educational performance.
Cannabis use causes mental illness, psychosis and schizophrenia.
Cannabis can never be used as a medicine.
(Source: Cannabis Its Harmful Effects, Mary Bretts, May 2007, published at www.eurad.net)