ICSDP tries to clarify cannabis claims

Cannabis is a genus of flowering plants that includes three different species, Cannabis sativa, C. indica, C. ruderalis. These species are indigenous to central Asia and the Indian subcontinent. Cannabis has long been used for hemp fibre, for hemp oils, for medical purposes and as a recreational drug.

Cannabis plants produce a group of chemicals called cannabinoids, which produce mental and physical effects when consumed. Cannabinoids, terpenoids, and other compounds are secreted by glandular trichomes that occur most abundantly on the floral calyxes and bracts of female plants. As a drug it usually comes in the form of dried flower buds (marijuana), resin (hashish),  or various extracts collectively known as hashish oil. In the early 20th century, it became illegal in most of the world to cultivate or possess Cannabis for sale or personal use. Different types of Cannabis plants are cultivated for different purposes:

• plants cultivated for fiber and seed production, described as low-intoxicant, non-drug, or fiber types.
• plants cultivated for drug production, described as high-intoxicant or drug types.
• escaped, hybridised, or wild forms of either of the above types.

Cannabis plants produce a unique family of terpeno-phenolic compounds called cannabinoids, which produce the "high" one experiences from consuming marijuana. There are 483 identifiable chemical constituents known to exist in the cannabis plant, and at least 85 different cannabinoids have been isolated from the plant. The two cannabinoids usually produced in greatest abundance are cannabidiol (CBD) and/or Δ⁹-tetrahydrocannabinol (THC), but only THC is psychoactive. Non-drug plants produce relatively low levels of THC and high levels of CBD, while drug plants produce high levels of THC and low levels of CBD. When plants of these two chemotypes cross-pollinate, the plants in the first filial (F₁) generation have an intermediate chemotype and produce similar amounts of CBD and THC. Female plants of this chemotype may produce enough THC to be utilized for drug production.

While some countries banned the use of Cannabis, some allow it to be used for medical purposes. In India Cannabis  is tolerated because of some customs associated with the Hindu religion.

This is what WHO website (7) says about Cannabis:

Acute health effects of cannabis use

The acute effects of cannabis use has been recognized for many years, and recent studies have confirmed and extended earlier findings. These may be summarized as follows:

• Cannabis impairs cognitive development (capabilities of learning), including associative processes; free recall of previously learned items is often impaired when cannabi is used both during learning and recall periods;
• Cannabis impairs psychomotor performance in a wide variety of tasks, such as motor coordination, divided attention, and operative tasks of many types; human performance on complex machinery can be impaired for as long as 24 hours after smoking as little as 20 mg of THC in cannabis; there is an increased risk of motor vehicle accidents among persons who drive when intoxicated by cannabis.

Chronic health effects of cannabis use

• selective impairment of cognitive functioning which include the organization and integration of complex information involving various mechanisms of attention and memory processes;
• prolonged use may lead to greater impairment, which may not recover with cessation of use, and which could affect daily life functions;
• development of a cannabis dependence syndrome characterized by a loss of control over cannabis use is likely in chronic users;
• cannabis use can exacerbate schizophrenia in affected individuals;
• epithetial injury of the trachea and major bronchi is caused by long-term cannabis smoking;
• airway injury, lung inflammation, and impaired pulmonary defence against infection from persistent cannabis consumption over prolonged periods;
• heavy cannabis consumption is associated with a higher prevalence of symptoms of chronic bronchitis and a higher incidence of acute bronchitis than in the non-smoking cohort;
• cannabis used during pregnancy is associated with impairment in fetal development leading to a reduction in birth weight;
• cannabis use during pregnancy may lead to postnatal risk of rare forms of cancer although more research is needed in this area.

The health consequences of cannabis use in developing countries are largely unknown beacuse of limited and non-systematic research, but there is no reason a priori to expect that biological effects on individuals in these populations would be substantially different to what has been observed in developed countries. However, other consequences might be different given the cultural and social differences between countries.

Therapeutic uses of cannabinoids

Several studies have demonstrated the therapeutic effects of cannabinoids for nausea and vomiting in the advanced stages of illnesses such as cancer and AIDS. Dronabinol (tetrahydrocannabinol) has been available by prescription for more than a decade in the USA. Other therapeutic uses of cannabinoids are being demonstrated by controlled studies, including treatment of asthma and glaucoma, as an antidepressant, appetite stimulant, anticonvulsant and anti-spasmodic, research in this area should continue. For example, more basic research on the central and peripheral mechanisms of the effects of cannabinoids on gastrointestinal function may improve the ability to alleviate nausea and emesis. More research is needed on the basic neuropharmacology of THC and other cannabinoids so that better therapeutic agents can be found.

And now this is what the International Centre for Science in Drug Policy (ICSDP) says:

Many scientists are increasingly frustrated by the disregard of scientific evidence on cannabis use and regulation. To set the record straight, the International Centre for Science in Drug Policy (ICSDP), a global network of scientists working on drug policy issues, released two groundbreaking reports (1) today evaluating the strength of commonly heard cannabis claims.

"State of the Evidence: Cannabis Use and Regulation," (2) is a comprehensive overview of the scientific research on major claims made about cannabis. It is paired with a summary report, "Using Evidence to Talk About Cannabis," (3) which equips readers with evidence-based responses to the claims.

The regulation of recreational cannabis markets has become an increasingly important policy issue in a number of jurisdictions. Some states in the US and a few countries in Latin America legalize and regulate the adult use and sale of cannabis for non-medical purposes. Globally, the issue of cannabis regulation is front and center in a growing number of jurisdictions, including Canada, Jamaica, Italy, Spain, Latin America, as well as several U.S. states set to vote on legalization initiatives in 2016.

"We are at a critical juncture, as more and more jurisdictions are reconsidering their policies on cannabis," said Dr. Dan Werb, Director of the ICSDP. "Yet, the public discourse around cannabis is filled with frequently repeated claims that are simply not supported by the scientific evidence. Given that policy decisions are influenced by public opinion and media reports, there is a serious danger that misrepresenting the evidence on cannabis will lead to ineffective or harmful policy."

To investigate this issue, the ICSDP convened scientists to conduct a review of thirteen oft-repeated claims about cannabis use and regulation (4). The review found that none of the claims were strongly supported by the scientific evidence.

The majority of cannabis use claims outlined in the reports tend to either misinterpret or overstate the existing scientific evidence. Dr. Carl Hart, Professor in the Departments of Psychology and Psychiatry at Columbia University, explained, "The claim that cannabis is a 'gateway' drug, for example, confuses correlation and causation. Worse still is the fact that a false claim like 'cannabis is as addictive as heroin' is reported as front page news. The evidence tells us that less than 1 in 10 people who use cannabis across their lifetime become dependent, whereas the lifetime probability of becoming heroin-dependent is closer to 1 in 4. False claims like these hamper public understanding of these issues and ultimately lead to harmful policies."

"This in-depth global research refutes the false claim that legalizing and regulating cannabis would automatically lead to huge increases in use, to levels like those seen for tobacco and alcohol," noted Mr. Steve Rolles, Senior Policy Analyst at the UK-based Transform Drug Policy Foundation. "With a growing body of evidence from more and more places reforming their drug laws, it is time our leaders stopped scare-mongering and came clean with the public about the facts when it comes to regulating cannabis."

The new reports are a resource for journalists, policymakers, and members of the general public who would like to engage with the complex issues surrounding global cannabis use and regulation. Scientists and academics will be holding conversation on Twitter using the hashtag #CannabisClaims (5) at the @icdsp (6) handle starting on August 12, 2015. Interested parties can also sign up for the ICSDP newsletter to get updates on how supporters around the world are coming together to bring scientific evidence to the public discourse on cannabis.

About the International Centre for Science in Drug Policy
The International Centre for Science in Drug Policy (ICSDP) is a network of scientists and academics from all global hemispheres committed to improving the health and safety of communities and individuals affected by illicit drugs by working to inform illicit drug policies with the best available scientific evidence. With the oversight of a Scientific Board made up of leading experts on addictions, HIV, and drug policy, the ICSDP conducts research and public education on best practices in drug policy. This work is undertaken in collaboration with communities, policymakers, law enforcement and other stakeholders to help guide effective and evidence-based policy responses to the many problems posed by illicit drugs.

According to ICSDP website (3)...

CLAIM:
“Cannabis [is] as addictive as heroin.” –
STRENGTH OF SUPPORTING EVIDENCE: Weak
BOTTOM LINE:
A lifetime of cannabis use carries a low risk of dependence (9%), while the
risk of cannabis dependence is very low among those who report using it for one year (2%) or
even 10 years (5.9%). This is much lower than the estimated lifetime risk of dependence to
heroin (23.1%).

CLAIM:
“[D]id you know that marijuana is on average 300 to 400 percent stronger than it was
thirty years ago?” –
Health Canada advertisement
STRENGTH OF SUPPORTING EVIDENCE: Moderate
BOTTOM LINE:
Although this claim overstates the existing evidence, studies do suggest that
there have been increases in THC potency over time in some jurisdictions.

CLAIM:
“I’m opposed to legalizing marijuana because it acts as a gateway drug.” –
Enrique Peña
Nieto, President of Mexico

STRENGTH OF SUPPORTING EVIDENCE: Weak
BOTTOM LINE:
Evidence to date does not support the claim that cannabis use causes subsequent use of “harder” drugs.

CLAIM:
Cannabis use “can cause potentially lethal damage to the heart and arteries.” –
World Federation Against Drugs

STRENGTH OF SUPPORTING EVIDENCE: Weak
BOTTOM LINE:
There is little evidence to suggest that cannabis use can cause lethal damage
to the heart, nor is there clear evidence of an association between cannabis use and cancer.

CLAIM:
Cannabis use lowers IQ by up to 8 points.
STRENGTH OF SUPPORTING EVIDENCE: Weak
BOTTOM LINE:
There is little scientific evidence suggesting that cannabis use is associated
with declines in IQ.

CLAIM:
Cannabis use impairs cognitive function.
STRENGTH OF SUPPORTING EVIDENCE: Moderate
BOTTOM LINE:
While the evidence suggests that cannabis use (particularly among youth)
likely impacts cognitive function, the evidence to date remains inconsistent regarding the severity, persistence, and reversibility of these cognitive effects.
CLAIM:
“[Cannabis] is a drug that can result [in] serious, long-term consequences, like schizophrenia.”
Kevin Sabet, Smart Approaches to Marijuana (Baca, 2015)
STRENGTH OF SUPPORTING EVIDENCE: Weak
BOTTOM LINE:
While scientific evidence supports an association between cannabis use and
schizophrenia, a causal relationship has not been established.
CLAIM:
“We are going to have a lot more people stoned on the highway and there will be consequences.” –
Rep. John Mica (R-Fla.)

STRENGTH OF SUPPORTING EVIDENCE: Weak
BOTTOM LINE:
While experimental studies suggest that cannabis intoxication reduces motor
skills and likely increases the risk of motor vehicle collisions, there is not sufficient data to suggest that cannabis regulation would increase impaired driving, and thereby traffic fatalities.

Well what I think is there isn't sufficient evidence to confirm these claims that are being made in the public domain. Still work needs to be done. Until then this uncertainty  persists.

References:

1. http://www.icsdp.org/cannabis_claims_reports

2. https://d3n8a8pro7vhmx.cloudfront.net/michaela/pages/61/attachments...

3. https://d3n8a8pro7vhmx.cloudfront.net/michaela/pages/61/attachments...

4. http://www.icsdp.org/cannabis_claims

5. https://twitter.com/search?q=%23CannabisClaims&src=typd

6. https://twitter.com/icsdp

7. http://www.who.int/substance_abuse/facts/cannabis/en/

For more information or to arrange a media interview, please contact:
Nazlee Maghsoudi
Knowledge Translation Manager, ICSDP
+1 (647) 694-9199
nmaghsoudi [at] icsdp.org

SOURCES:

WHO and

International Centre for Science in Drug Policy (ICSDP)

http://www.icsdp.org