Synthetic cannabinoids, or synthetic cannabinoid receptor agonists, bind to the same receptors as cannabis. Currently, there are 14 families of synthetic cannabinoids, all of which have very different chemical structures. Although they bind in the same places as cannabis, their effects can vary widely — as can their safety.
As these novel chemicals are designed and consequently banned, new versions are created to take their place. Worryingly, as they evolve, some fear that they are becoming more potent.
Synthetic cannabinoids — which are sold under names such as K2 and Spice — are marketed as having similar effects to marijuana, but they can be many times more potent.
They are often sprayed onto plant matter and sold as “herbal incense,” or they may be labeled “not for human consumption” and marketed as “legal” marijuana. Sometimes, they are even sold as “research chemicals.”
The dangers of synthetic cannabinoids
Although the effects of synthetic cannabinoids can vary, they are, overall, considered to be more dangerous than cannabis.
A systematic review published last year looked at 106 studies. They found many adverse events — including tachycardia, agitation, nausea, generalized tonic-clonic seizures, and 26 deaths. They also noted psychiatric issues, such as first-episode psychosis.
Less commonly, stroke, myocardial infarction (or blockage of blood to heart tissue), rhabdomyolysis (or the breakdown of muscle tissue), and hyperemesis (or severe nausea) were reported.
The first clinical study to compare the adverse effects of a synthetic cannabinoid overdose against marijuana-using controls in emergency department admissions found that synthetic cannabinoid overdoses had “significantly pronounced neurotoxicity and cardiotoxicity compared with marijuana.”
Another reported trend is that synthetic cannabinoid users are often marijuana users, too. This relationship appears to be one way: a study on adolescents found that marijuana use predicted future synthetic cannabinoid use, but also that synthetic cannabinoid use did not predict future marijuana use.
A study published in the journal Pediatrics set out to look in more detail at synthetic cannabinoid use among high school seniors, measure its prevalence, and examine any correlated drug use.
Earlier studies have found strong associations between the use of synthetic cannabinoids and the abuse of other substances. However, most of this work focused on lifetime use or past-year use.
The current study concentrated on the past 30 days. Obtaining this more granular information gives a better picture of which individuals are at a higher risk; people who have tried synthetic cannabinoids within their lifetime or the previous 12 months might no longer take them.
“Thus, our aim in this article is to determine risk factors for current use of SCs [synthetic cannabinoids] in a nationally representative sample of high school seniors with a particular focus on recency of use of other drugs.”
They used data from Monitoring the Future (MTF), which is a nationally representative sample of high school students including data from around 130 public and private schools across 48 states. MTF interview around 15,000 high school seniors each year.
Data on synthetic cannabinoid use
The data showed that, in the past 30 days, 2.9 percent of high school seniors had used synthetic cannabinoids, and 1.4 percent had used them on 3 or more days in the past month. Eight out of 10 synthetic cannabinoid users reported being current cannabis users.
Around 80 percent of synthetic cannabinoid users also use cannabis.
Compared with marijuana-only users, synthetic cannabinoid users were more likely to have parents with lower education levels. They were also more likely to report recent use of all other drugs, other than alcohol, on the questionnaire.
The following list gives a comparison between drug use in synthetic cannabinoid users vs. that of cannabis-only users:
- LSD: 14.8 percent vs. 3.4 percent
- opioids: 13.6 percent vs. 5.7 percent
- cocaine: 10.6 percent vs. 3.3 percent
- heroin: 5.9 percent vs. 0.1 percent
Compared with marijuana-only users, synthetic cannabinoid users were more likely to attribute greater risk to occasional marijuana use and less risk to synthetic cannabinoid use. This, as the authors write, indicates “a lack of knowledge about the relative health risks of SC compared with marijuana.”
Those who reported using synthetic cannabinoids on 10 or more of the past 30 days were more likely to be male and African American. Almost half of this group (48.9 percent) reported using marijuana 20 or more times in the previous month.
Limitations and moving forward
The authors are quick to note the shortfalls of this study. All questionnaire-based studies come with the problems of self-reporting, such as memory issues and the potential for dishonesty. Also of note is the fact that this survey did not include anyone who had dropped out of high school.
Regardless of the limitations, the findings are important. The authors hope that the study might help to steer interventions regarding synthetic cannabinoid use and pinpoint those at risk. The authors write:
“Prevention needs to be focused primarily on marijuana users, especially marijuana users with risk factors discovered in this analysis. […] Marijuana users who use other drugs, in particular, are at highest risk for currently using SCs, so particular focus needs to be paid to these individuals at high risk.”
Because the team found that synthetic cannabinoid users were less likely to perceive synthetic cannabinoids as dangerous, education might be a good starting point.
Although cannabis is certainly not risk-free, synthetic cannabinoids have more significant health impacts, and worryingly, are becoming more potent as new chemicals are designed.
At the moment, synthetic cannabinoids are a hot topic in drug and addiction research; studies investigating their prevalence and long-term effects are released with regularity.
Understanding the drugs and the problems that they can cause is only part of the solution, and understanding who is at risk of adopting synthetic cannabinoid use and why is vital for implementing timely interventions.