“The longer you hold in the smoke, the more you feel the effects”
New cannabis smokers are often told to hold smoke in their lungs for as long as they can to fully absorb the cannabinoids. While on the surface this appears to make sense, there’s actually very little supporting evidence. In fact, holding the smoke in for longer than a few seconds might only serve to increase tar deposits in the lungs.
“Cannabis is 10 times stronger today than it was in the Sixties”
Though not necessarily a myth, the assertion that today’s cannabis is higher in average potency than it was “at Woodstock” cannot be reliably proven. This is because early researchers measured THC by gas chromatography, which involved heating and therefore breaking down the molecule. Nowadays, THC is measured by liquid chromatography, so there’s no common basis for comparison. The sample size is also much, much larger than it used to be. In the 1970s, researchers were lucky if they had access to 18 seizures in a year, whereas nowadays they have access to thousands.
In any case, even though this skewed comparison does show a general upward trend in the average potency of cannabis, it doesn’t support the implied suggestion that the plant has become more dangerous. Evidence suggests that people only smoke as much as they need to reach their desired state. In other words, the higher the potency, the less users need—and ultimately, the fewer carcinogens they inhale.
“Cannabis is a gateway drug”
This Reefer Madness-style argument for continued prohibition has zero basis in fact. While it is true that most habitual drug users are exposed to cannabis before any harder drugs, this is only to be expected considering that cannabis is the most prevalent illicit substance worldwide. It certainly doesn’t prove causality. But if it did, alcohol and tobacco would be the original gateway drugs, since most cocaine and heroin addicts are exposed to them even earlier.
“Cannabis is non-addictive”
Only a relatively small number of cannabis users become addicted—9% of 8,000 respondents according to one survey, compared to 32% for nicotine. However, regular use can easily lead to habituation and psychological dependence.
Withdrawal symptoms include irritability, lethargy, physical discomfort, difficulty sleeping, diminished appetite, and a loss of pleasure in once enjoyable activities (anhedonia). Unlike withdrawal symptoms from other drugs, such as alcohol, tobacco, and heroin, these effects tend to be mild. They also tend to fade after two to four days, or within six weeks for heavy users.