On the cognitive level cannabis may lead to the development of schizophrenic disorders, memory loss, and hallucinations especially in cases of high doses. Long term use of cannabis is linked to anxiety related disorders like paranoia. A loss of reality is the most common symptom of long term cannabis abuse; often one cannot in this condition think lucidly and rationally and the only thought uppermost in the mind is about the procurement of the drug.
Cannabis smoke is believed to be more lethal as compared to cigarette smoke and leads to development of chronic bronchitis and edema. The risk of cancer is found to be greater in young cannabis users as compared to adults.