evidence: There is a widespread misconception that cannabis is not addictive. "This couldn’t be further from the truth," says D'Souza. "There is compelling evidence from both animal studies and humans that some people get addicted to cannabis (~30%) for reasons we don’t fully understand." Addiction to cannabis is directly related to its THC content. D'Souza believes that the false perception may stem from several decades ago, when the THC content was lower, and the drug was likely less addictive. But as cannabis becomes more potent, he fears that there may be greater rates of addiction in the future.