The effects of cannabis on the brain and respiratory system
Long term effects on the brain
Recent research indicates that in common with other addictive drugs such as heroin, nicotine and amphetamines, cannabis activates the release of dopamine in the brain. Dopamine release forms part of the brain's reward mechanism, which is involved in dependence . Some regular cannabis users become psychologically dependent and can experience a variety of withdrawal symptoms when they stop using. Cannabis is also known to act on the opioid system of the brain, which may explain its properties in common with morphine and heroin, for example pain-relief.There are conflicting findings on whether the long-term use of cannabis leads to impairment of cognitive functions of the brain. It certainly has a short-term effect, but recent research has shown that even in long-term heavy users, this disappears within seven days of stopping use. Cannabis users are often said to be lacking in motivation, but there is little research in this area. The populations that have been studied were frequently psychiatric referrals, and it has been revealed that supposed sufferers of cannabis-induced "amotivational syndrome" often had signs of clinical depression prior to their use of cannabis. Nevertheless, there is little doubt that cannabis can have some effect on behaviour and performance.
There has been evidence for some time of a possible link between cannabis and schizophrenia. Where an individual is already suffering from a mental illness, heavy cannabis use is likely to aggravate any psychotic episode and reduce the effect of any drugs taken to combat it. Research has shown a link between taking cannabis and depression. For example, in a recent study in Australia, women who had regularly taken cannabis as adolescents were 5 times more likely to suffer depression as adults. However research has still to rule out that the association may be due to common social, family and contextual factors increasing the risk of both cannabis use and depression. While there has read more
