Originally Posted by REH7380

A current doctoral thesis from Karolinska Institutet, Stockholm, on the neurobiological effects of early life cannabis exposure, gives support for the cannabis gateway hypothesis in relation to adult opiate abuse. THC exposed rats showed increased motivation for opiate drug use under conditions of stress. However, the cannabis exposure did not correlate to amphetamine use.
Research has shown that cannabis acts to increase heart frequency by as much as 40 beats per minute. A study reported by The American Heart Association in February 2000, concluded that smoking marijuana can precipitate a heart attack in persons with preexisting heart conditions. One hour after smoking marijuana, the likelihood of having a heart attack is four and one-half times greater than if the person had not smoked, according to the research.
An additional health concern is the effect that marijuana smoking has on the lungs. Cannabis smoke carries more tars and other particulate matter than tobacco smoke.
More seriously, marijuana has been linked to the onset or worsening of certain psychiatric conditions, including panic disorder, schizophrenia, and depersonalization disorder. Persons diagnosed with or at risk for these conditions should not use marijuana.
No health hazards or side effects are known in conjunction with the proper administration of designated therapeutic dosages." Smoking the herb, however, "… leads almost at once to euphoric states (pronounced gaiety, laughing fits)," according to the PDR, while "long term usage leads to a clear increase in tolerance for most of the pharmacological effects." The ability to safely operate automobiles and machinery can be impaired for up to eight hours after ingesting the herb. Chronic abuse results in "laryngitis, bronchitis, apathy, psychic decline and disturbances of genital functions," according to the PDR.
Some people may be hypersensitive to marijuana. They may be allergic or hypersensitive to the plant. Chronic sinus fungal infections have been linked to chronic marijuana smoking.
THC Substance abuse A substance derived from the hemp plant Cannabis sativa, the leaves of which are smoked, producing a hallucinogenic effect due to the neurochemical Δ9-tetrahydrocannabinol–THC, which has a cognate THC receptor in the brain Immune system THC blocks monocyte maturation Nervous system Impaired motor skills, defective eye tracking and perception; THC receptors are most abundant in the hippocampus, where memory is consolidated, explaining MJ's detrimental effect on memory and least abundant in the brainstem, explaining why death by overdose is unknown with chronic marijuana abuse; heavy use is associated with residual neuropsychological effects, as evidenced by ↑ perseverations on card-sorting, and ↓ learning of lists Respiratory tract MJ is inhaled or 'toked' in a fashion that differs from that of tobacco; in order to maximize THC absorption and elicit the desired 'high.', the subject prolongs inhalation, markedly ↑ carbon monoxide and tar, and thus is possibly more detrimental than tobacco smoke Therapeutic uses MJ is an analgesic, but unusable as such, due to the inseparable hallucinogenic effect; it is of use for 1. Control of N&V in terminal CA–2 antiemetic cannabinoids are