From: [m--e--d] at [demon.co.uk] (Michael Read) Newsgroups: alt.drugs Subject: THE HEALTH AND PSYCHOLOGICAL CONSEQUENCES OF CANNABIS USE Date: Wed, 08 Nov 1995 08:23:27 GMT The following information is adapted from the report of the Australian National Task Force on Cannabis. This is about the most balanced presentation of the case for and against this substance which I have read. It relies on consensus in the field of cannabis research rather than quoting leftfield studies be they pro or anti drug use. Where health outcomes remain contraversial, this is indicated. Empirically rigorous, reliable and valid findings are emphasised at the expense of the more cowboy and cavalier research which is often jumped on by those with a political axe to grind (i.e. legalisers and prohibitionists). The Drug THC and its metabolites are highly fat soluble, and may be stored and accumulated in the adipose tissue (including the fatty tissue of the brain). Over time, this accumulated material is released and cleared from the body. The compounds may be tracable in small amounts for days or weeks after consumption. THC can be measured in the adipose tissue for as long as 28 days. Regular smokers probably process cannabis products faster than new users, and the half life could be expected to be 24 hours as compared to over 48 hours. All of this is prone to high levels of indivual variability. The implications of the above for health outcomes are unknown. Subjective intoxication does not last more than a few hours and THC stored in the fatty tissues does not appear to remain psychoactive. Cannabis `flashbacks' from slow release are considered unlikely. It is generally accepted that this slow release has no noticable psychoactive effects. Acute Psychological and Health Effects All the sought after effects (euphoria, relaxation, perceptual alterations etc.) plus possible anxiety, panic and unpleasant feelings (most often in new users). Large (oral) consumption is most likely to lead to these effects (as well as possibly hallucinations and delusions). Physically, cannabis will probably increase heart rate and change blood pressure (up whilst sitting, down whilst standing for eg). No real clinical significance for healthy hearts. Acute toxicity very low. No recorded overdose. Cannabis and Driving Major acute health risk as cannabis affects psychomotor skills. Dose-related impairments of a broad spectrum of cognitive/behavioural functions (dose-related means it's more likely to be causal). However, cannabis intoxication as a cause of accidents is a toughie - stoned drivers tend to be more cautious and quoted figures about how many crash victims have cannabis in their blood (between 4 and 40%) tell you very little unless you know the base rates for drivers in general and non-carsh victims. Also you'd have to control for other drugs. However, generally experts concur that restrictions on smoking cannabis and driving would be necessary regardless of the legal status of cannabis per se. The effects of alcohol and cannabis on driving are probably additive rather than synergistic. Chronic Cannabis Use Assume the following is lab work rather than real world research unless otherwise stated. The actual meaning of the research clinically is open to debate until we have some decent prospective epidemiological data (my field! ;)). Cannabis smoke is mutagenic (damages genetic material), and possibly carcinogenic. Impairments to certain immune functions have been demonstrated in animals (including lowered resistance to introduced infection). This research has often used high doses. No conclusive evidence in humans, but it's difficult to argue that there is no possibility of any impairment through heavy chronic use. Note however, that HIV doesn't turn into AIDS more rapidly in heavy cannabis users. No evidence of damage to the cardiovascular system - may be risk to those with high blood pressure/cerebrovascular disease/coronary atherosclerosis etc. Harm minimisation would suggest these people shouldn't use cannabis (it'd be a caution in a theraputic setting and a no no to recreational use). May cause symptoms of chronic bronchitis (coughing, sputum, wheezing), predispose users to lung cancer, and possibly result in mouth throat and airways cancers in young adults. Many such studies are complicated by the existance of multiple risk factors. There is a need for more case control studies here. There are changes brought about in animals' reproductive systems but the significance for human users remains unclear. Harm minimization would suggest that it is unwise for growing adolescents or those with established fertility problems to take cannabis. Cannabis use during pregnancy probably affects the development of the foetus (i.e. lower birth weight), but the effect on subsequent development and whether there is an increased risk of abnormalities is unclear. Until this is clarified, women would be advised to avoid cannabis use throughout pregnancy. One study has indicated increased rates of childhood leukaemia in children of women who smoked cannabis during their pregnancy - this needs to be replicated. Psychological Effects of Chronic Use Much of the research which links cannabis use with delinquency and deviance could equally be interpreted as expression as of causation. There is no clear evidence that cannabis use affects adolescent psychological adjustment. There may be a modest effect on school performance - exaggerated by lower pre-existing expectations and the like. There is weak evidence for impact upon family formation, mental health and involvement in drug-related crime. The causal link is not established and many other factors are of far greater significance. However, on balance, cannabis use - particularly heavy or regular use - should be discouraged among adolescents. Adult adjustment - the case for an amotivational syndrome has not been made out. If it does exist, it is likely that it is a rare occurrence, even amongst heavy regular users. Dependence - probably occurs in some heavy users. Tolerance has been demonstrated, and a mild withdrawal syndrome is reported by some chronic heavy users when they cease to use. Some use becomes uncontrolled, and continues in the face of personal, financial or other social difficulties brought about by use. May be similar to the risk from alcohol. Most likely amongst daily users of the drug. Recognition has been delayed because few people seek help in stopping use and because many dependent users have more serious problems (i.e. opiate dependency). Probably there are less associated problems and a higher rate of spontaneous remission than with alcohol dependency. Cognitive - No severe impairment from chronic use, substle impairments of higher functions (memory, attention, organisation of information etc.) May affect everyday functioning (particularly in adolescents who are borderline educational aptitude, and adults in demanding jobs). Longer use - more pronounced impairment, but there is considerable individual variation in susceptability and reversibility on abstinence. Brain Damage - No reliable research evidence for this. Psychosis - Heavy use may lead to acute toxic psychosis, but less evidence for a chronic functional psychosis brought about by cannabis use. Difficult to distinguish these cases from cases where schizophrenic and manic depressives self medicate with cannabis. It is possible the drug could unmask a latent psychosis in a vulnerable individual or exacerbate an existing disorder Theraputic Effects A refreshing balance...Anti-emetic, treatment of glaucoma, (possible) anti-spasmodic, (possible) anti-convulsive, (possible) anagesic, (possible) anti-asthma, (possible) assistance for HIV/AIDS patients in maintaining weight and positive mood. Increasing Potency - Needs more research to ascertain what if any the impact will be. Are more more potent forms (whatever certain people may argue), but likely users will titrate their intake. May increase toxic reactions, may decrease chronic respiratory problems...Who knows? Hope that's of interest