(Please direct me to previous questions on ResearchGate that deal with this issue. I cannot find any. Apologies if I have overlooked them).
The new laws in two USA States that legalized marijuana use (Colorado and Washington) have instigated new debate in Australia about legalizing the use of the drug here. Meanwhile Associated Press reports (7 April) that the Netherlands has recently taken a harder line towards marijuana including banning tourists (except in Amsterdam) from visiting coffee shops where marijuana is sold.
Supporters for the legalization of marijuana believe that it will eliminate the illegal trade and associated crime, yield a valuable tax-source and reduce policing costs
Opponents argue that there is clear and growing evidence between marijuana use and psychosis, and its potential to act as a gateway drug leading to use of more dangerous drugs. They also say legalization could hasten the use by teenagers and cite mounting evidence showing that the earlier one starts using marijuana, the more devastating the effects especially on brain development.
Too much of the debate in the past has been on emotional grounds.
We would appreciate hearing from people who can cite good quality scientific data; or case studies from people working in the field with good quality anecdotal ‘evidence’, particularly in relation to the link with mental health.
19 U.S. jurisdictions have legalized marijuana for medical use, so partial legalization. Of the 14 we analyzed using ARIMA time series analyses, we only found increased prevalence of cannabinoids among drivers in 3: http://apps.dmv.ca.gov/about/profile/rd/r_d_report/Section_6/S6-242.pdf
Thanks Sean for the reference to the article on the Portuguese experience (decriminalization of all illegal drugs). In 2001, Portugal decriminalized use, acquisition and possession of all illicit drugs when conducted for personal use. Sales of all illicit drugs remained as criminal offences.
The authors of the article reviewed the various reports / evaluations of the policy change and expressed disappointment at their quality indicating diametrically opposed policy conclusions. On one hand, some commentators regarded the policy change a ‘disastrous failure’; while on the other, it was deemed a ‘resounding success’. Sadly, the variability in such ‘evaluations’ gives little confidence to both policy makers and the general public about the likely benefits or disadvantages of such ‘policy reform’.
Thanks Scott for your report on the 19 U.S. jurisdictions, which have legalized marijuana for medical use (partial legalization) where you found, only increased prevalence use of cannabinoids among drivers in 3 States. (:http://apps.dmv.ca.gov/about/profile/rd/r_d_report/Section_6/S6-242.pdf )
So it appears that there is some useful experience about decriminalizing marijuana (or ‘partially legalizing’ it) but no good quality evidence about legalizing marijuana (to the extent it is treated similarly to alcohol for example)?
I do not profess to be an expert in this area but have been following the issue since I was a postgraduate student in the USA (1976-79). Then I was often amused with the apparent widespread use by university students and university educated professionals. Most users I knew were adamant about its ‘relative harmlessness’!
In the mid 1980s, we had an overseas ‘expert’ who came to Australia to tell us how ‘safe’ marijuana was and that ‘there was no link between mental health problems and its use’. It seems that the accumulating evidence has now proven that self-professed ‘expert’ wrong. Many other people especially relatives of regular users, and health professionals expressed concern with his assertions. More credible colleagues who worked in drug rehabilitation warned us that regular use of marijuana was far from safe. They attested that from their experience, many regular users were very negatively affected and ‘bloody useless’ in functioning in employment etc. They remain concerned about what they call ‘mis-informed’ efforts to legalize the drug (as opposed to decriminalization with very strict conditions).
Therefore, it is no wonder the general population is highly confused about the relative safety or danger of marijuana and any likely benefits of its full legalization.
So I pose the question again what other EVIDENCE is there AGAINST the legalization of marijuana (as opposed to decriminalization), and I encourage responses from people working in the field with anecdotal ‘evidence’, particularly in relation to the link with mental health.
A new study of young casual marijuana smokers (Journal of Neuroscience) found potentially harmful changes to their brains.
The drug is reputed to have altered regions of the mind related to motivation and emotion. This is purported to be different to many other marijuana related research that focused on heavy, chronic users.
The study showed a direct correlation between the amounts of marijuana smoked and brain abnormalities. The researchers said they were seeing changes in the core brain regions of 18-25 year olds that one should not be putting at risk.
This study concurs with other research showing marijuana use has significant effects on young people because their brains are still developing. One of the researchers said that people under 30 should only use marijuana if they need it to manage pain from a terminal illness.
The National Institute on Drug Abuse and the White House Office of National Drug Control Policy funded it.
A new French study reported in the Journal of the American Heart Association warns of dangers of marihuana use by young people.
Researchers analyzed serious cardiovascular-related complications following marijuana use and found it was associated with cardiovascular-related complications, even death, among young and middle-aged adults
According to the researchers "The general public thinks marijuana is harmless, but information revealing the potential health dangers of marijuana use needs to be disseminated to the public, policymakers and healthcare providers”.
They warn that people with pre-existing cardiovascular weaknesses appear to be more prone to the harmful effects of marijuana. "There is now compelling evidence on the growing risk of marijuana-associated adverse cardiovascular effects, especially in young people," "
They concluded by agreeing that more research needs to look at how marijuana use might trigger cardiovascular events.
New study finds that legalizing medical marijuana doesn't increase use among adolescents:
http://www.sciencedaily.com/releases/2014/04/140423102754.htm?utm_source=feedburner&utm_medium=feed&utm_campaign=Feed%3A+sciencedaily%2Fmind_brain%2Faddiction+%28Addiction+News+--+ScienceDaily%29
Study reference:
1.Esther K. Choo, Madeline Benz, Nikolas Zaller, Otis Warren, Kristin L. Rising, K. John McConnell. The Impact of State Medical Marijuana Legislation on Adolescent Marijuana Use. Journal of Adolescent Health, 2014; DOI: 10.1016/j.jadohealth.2014.02.018
My previous post provides evidence contrary to the question asked. This is because I would have expected a scientific website such as this to host questions which ask for evidence FOR and AGAINST a hypothesis - NOT just evidence in one direction. Very odd indeed.
Thanks Russell for the link to this new study: According to the study at Rhode Island Hospital, which compared 20 years’ worth of data from States with and without MEDICAL MARIJUANA LAWS, legalizing the drug for medical use did not lead to increased use among adolescents.
This adds to considerable research on the effects of LEGALISING marihuana for MEDICAL USE under strict conditions (for which there seems to be some legitimate arguments).
I rephrase a previous comment I made: “…it appears that there is some useful experience about DECRIMINALIZING MARIJUANA (or ‘PARTIALLY LEGALIZING’ it e.g. for medical use) but no good quality evidence about fully LEGALIZING MARIJUANA (to the extent it is treated similarly to alcohol for example)?
You are correct Russell; scientific websites such as this should host questions, which ask for evidence FOR and AGAINST. I specifically posed the question deliberately seeking the latest evidence AGAINST the legalization of marijuana (as opposed to decriminalization). I actually expected to see a strong reaction from very vocal supporters for legalising marijuana (On a similar basis as alcohol) as they have been very active in our recent Federal election!
In addition, I do welcome them adding any good evidence that supports their case. Sadly, to date the evidence for fully legalising marijuana (On a similar basis as alcohol) appears to be lacking.
Further to my previous comments, I must admit I was expecting to see some strong support posted on this site for fully legalising marijuana, from vested interests; e.g. those linked to the tobacco industry who could stand to gain massive profits from the legal sales of marijuana should ‘full legalisation’ ever be allowed. I understand there are some on-line sites where it is purported that ‘employees’ or ‘sympathisers’ of the tobacco industry have been vigorously engaged in attempts to undermine the integrity of respected public health advocates.
Remember it was not long ago that such low-life constantly tried to undermine the clear evidence linking tobacco with lung cancer and numerous other health ailments. (e.g. Refer to some of the commentaries on the 50th Anniversary of the landmark 1964 Surgeon General’s Report on Smoking and Health ).
A New South Wales (Australia) government MP Kevin Anderson is planning to introduce a bill to legalize medicinal cannabis for selected cases such as for terminal cancer.
Mr Anderson said he shared the Premier’s “grave concerns” on the issue of the drug’s supply, which would need to be “through a tightly controlled and regulated process”.
A comprehensive review in the New England Journal of Medicine (June 4, 2014) by scientists from the National Institute on Drug Abuse (NIDA) summarizes research on marijuana's negative health effects and why risks are greatest for teenagers.
The review describes the risk for addiction of marijuana increases for daily or young users. It also offers insights into research on the gateway theory indicating that marijuana use, similar to nicotine and alcohol use may be associated with an increased vulnerability to other drugs.
The review literature shows that marijuana impairs driving which is worse when combined with alcohol. The authors note that because older studies are based on the effects of marijuana containing lower THC, stronger adverse health effects may occur with today's more potent marijuana.
The reviewers consider areas in which little research has been conducted such as the effects of marijuana legalization policies on public health.
They highlight marijuana's harmful effects on teenagers, an age group in which the brain rapidly develops, which could help explain increased risks from marijuana in this group. Research suggests that marijuana impairs critical thinking and memory functions and that these deficits persist for days after using. In addition, a long-term study showed that regular marijuana use in the early teen years lowers IQ.
The review authors said, "It is important to alert the public that using marijuana in the teen years brings health, social, and academic risk,"…and “…that early marijuana use can interfere with crucial social and developmental milestones and can impair cognitive development."
They conclude that marijuana use is likely to increase with the legalization of marijuana for medical or recreational purposes. In addition, they warn that as use increases, so might the number of people likely to suffer negative health consequences.
The following is an extract from the Sunday Telegraph (Sydney, Australia) of 15 June 2014.
Tasmanian company Tasman Health Cannabinoids has applied for a license to grow cannabis to conduct a clinical study in conjunction with the University of Tasmania. The NSW Health Minister has softened her stance on the use of cannabis for medicinal purposes, saying she supports a proposed trial.
The proposal seeks approval to extract the non-hallucinogenic component from cannabis grown in Tasmania with a view to clinical trials to prove its safety and effectiveness. It will be grown indoors in a highly secure environment similar to the security protocols in Canada.
The NSW government has faced increasing criticism for rejecting the findings of a cross party committee last year that recommended legalizing cannabis for the terminally ill.
A university academic said there was good evidence that medicinal cannabis worked from an analgesic point of view as did morphine.
It appears that any proposal for legalizing cannabis would be under very controlled circumstances to minimise increased use by the general public especially young people who are vulnerable to the adverse effects of cannabis.
The Wall St Journal reports that New York State has agreed to legalize certain forms of marijuana for patients with a limited range of diseases.
It would permit only doctors to prescribe marijuana, in forms including oil-based and vapor, to patients with a restricted range of conditions (eg. cancer, AIDS, epilepsy and multiple sclerosis). It would not legalize smokable forms of the drug.
The Governor said "Medical marijuana has the capacity to do a lot of good for a lot of people who are in pain and suffering," "At the same time, it's a difficult issue, because there are also risks that have to be averted—public-health, public-safety risks. And we believe this bill strikes the right balance." He said he wanted to curb marijuana's potential to become a "gateway" drug.
This will make New York the 23rd state to legalize at least some forms of marijuana for medicinal purposes.
Medical-marijuana advocates were disappointed by the restrictions placed on the program. They feel the method of intake should be decided between a patient and a doctor.
The latest request for limited decriminalisation of cannabis in Australia.
From Change.org.
“Quickly attracting 130,000 signatures … we wanted to make sure you saw this petition to decriminalise medicinal cannabis for the TERMINALLY ILL , that's taking off on change.org.
It's started by Lucy Haslam whose son is dying of terminal cancer, and already has a Nationals MP drafting new laws that could be debated with the NSW Premier's support in just six weeks' time. This issue looks close to winning.
Support is building among parliamentarians of all stripes – but Lucy needs a surge of public support on her petition to help show that this issue should finally be addressed. “
Click here to add your name to her petition and read on for more below: ( GO TO Change.org. )
Frequent cannabis use in adolescence is linked with problems in young adults.
The Lancet Psychiatry reports a new study by Australian and New Zealand researchers who combined data of 3765 participants who used cannabis from three large, longitudinal studies
They found that daily users of cannabis before age 17 are:
• 60% less likely to complete high school or obtain a degree compared to those who have never used the drug,
• are 7 times more likely to attempt suicide,
• have an 18 times greater chance of cannabis dependence, and
• Are 8 times as likely to use other illicit drugs in later life.
Seven developmental outcomes up to the age of 30 years recorded clear and consistent associations between frequency of cannabis use during adolescence and most young adult outcomes investigated, even after controlling for 53 potential confounding factors.
The risks increased relative to dose, with daily cannabis users showing the strongest effects.
According to one of the study authors Professor Richard Mattick, the findings are particularly timely that several US states and countries in Latin America have moved to decriminalise or legalise cannabis, which may lead to the drug becoming more accessible to young people.
The lead author, Dr Edmund Silins, stated that their results provide strong evidence that the prevention or delay of cannabis use is likely to have significant health and social benefits.
He cautioned efforts to reform cannabis legislation, which should be carefully assessed to ensure they reduce adolescent cannabis use and prevent potentially adverse effects on adolescent development.
Interesting that a reader has down-voted the evidence from the recent study reported in the eminent Lancet Psychiatry Journal. ( above)
Is this a supporter for the legalisation of cannabis who prefers that such respectable evidence warning of the dangers of this drug to young users was censored?
So far no one has been able to provide any compelling evidence for the support of the legalisation of cannabis ( as opposed to decriminalisation; or for medicinal use under carefully controlled conditions) !
Risk benefit analysis would suggest that palliative use for chronic pain would save lives - Leonard Jason & Elena Calandre's respective reports on Chronic Fatigue and Fibromyalgia syndromes suggest that 1 in 3 attempt suicide (none of the death certificates mentioned a history of depression). Its prohibition is hypocritical when the only Govt sponsored investigations into therapies (other than co-funding pharma's me-too anti-depressants & off-label experimenting) are in Spain.
Some recent papers on cannabis use and psychosis raise serious concerns. The Lancet paper is of particular concern concluding that ‘…that the risk of psychosis was five times higher for regular users of cannabis, adding to a growing body of evidence linking drug use and mental health disorders.” "This paper suggests that we could prevent almost one quarter of cases of psychosis if no-one smoked high potency cannabis,"
http://theconversation.com/is-the-medical-marijuana-debate-even-worth-having-37658
http://www.fpm.anzca.edu.au/about-fpm/pdfs/Michael%20Cousins%20Lecture.pdf
http://www.thelancet.com/pb/assets/raw/Lancet/pdfs/14TLP0454_Di%20Forti.pdf
A colleague recently sent me these 2 articles about Canada’s legalization of cannabis. The colleague has spent his career working with vulnerable youth particularly in tobacco and other drug use and is also expert on mental health issues. He said he is astounded by Canada’s decision which he believes will further normalize tobacco smoking and set tobacco control back decades. He is also very concerned about the mental health effects of cannabis on vulnerable youth. He strongly opposes legalization of cannibals for Australia.
You may have a different opinion? See articles attached
Cannabis Legalization and Psychiatric Disorders: Caveat “Hemp-tor”
by Tony P. George, Kevin P. Hill, and Franco J. Vaccarino
Implications of Cannabis Legalization on Youth and Young Adults
by Phil Tibbo, Candice E. Crocker, Raymond W. Lam, Jeff Meyer, Jitender Sareen, and Katherine J. Aitchison
Apparently many parents of teenagers, and health professionals are now very concerned about the new liberal cannabis laws in Canada. Have they been duped?
Adolescent cannabis use has been linked to an increased risk of depression and suicidal behavior in young adulthood, according to the first meta-analysis by a team of scientists.
The results reveal that cannabis use in adolescence could harmfully alter mental health, even in teenagers who did not report any depressive symptoms before starting cannabis.
The risk is particularly elevated in North America, where adolescents have higher rates of cannabis use compared to their peers in other developed countries. Canadian youth aged 15-25 constitute the majority of users of all ages (spanning 20-33 percent) while over 20 percent of adolescents in the United States report monthly use.
The research was conducted at the Research Institute of the McGill University Health Centre (RI-MUHC) and McGill University, in collaboration with the University of Oxford and Rutgers University-Camden. It is published in the journal JAMA Psychiatry (click below or cut and paste)
Association of Cannabis Use in Adolescence and ... - JAMA Network
https://jamanetwork.com/journals/jamapsychiatry/fullarticle/2723657
A recent edition of The Lancet Psychiatry presents more evidence of the link between cannabis use and mental illness.
The contribution of cannabis use to variation in the incidence of psychotic disorder across Europe ..
https://www.thelancet.com/journals/lanpsy/article/PIIS2215-0366(19)30048-3/fulltext
Between May 1, 2010, and April 1, 2015, we obtained data from 901 patients with first-episode psychosis across 11 sites and 1237 population controls from those same sites. Daily cannabis use was associated with increased odds of psychotic disorder compared with never users (adjusted odds ratio [OR] 3·2, 95% CI 2·2–4·1), increasing to nearly five-times increased odds for daily use of high-potency types of cannabis (4·8, 2·5–6·3). The PAFs calculated indicated that if high-potency cannabis were no longer available, 12·2% (95% CI 3·0–16·1) of cases of first-episode psychosis could be prevented across the 11 sites, rising to 30·3% (15·2–40·0) in London and 50·3% (27·4–66·0) in Amsterdam. The adjusted incident rates for psychotic disorder were positively correlated with the prevalence in controls across the 11 sites of use of high-potency cannabis (r = 0·7; p=0·0286) and daily use (r = 0·8; p=0·0109)
The Lancet Psychiatry ... Marta Di Forti et al. Open Access Published: March 19,
Hi Peter,
Take a look at my research page..I have written extensively on the neuro-chemical effects of marijuana (Novelty reset effect)..I noticed that you brought up the "gateway" label..the APA will tell you that the majority of people who try marijuana never go on to harder drugs...it is not considered a "gateway drug" by the scientific community...any adolescent use of reward pathway stimulating substances will always have a negative effect on neurological synapse growth...allostasis during formation...not a good thing...and of course there is the difference between CBD and THC...I have long been a proponent of marijuana growers voluntarily regulating the THC content just like alcohol proofing.....THC does modulate the dopaminergic pathways slightly...
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