The prohibition of cannabis is approaching its end in the U.S. Still, the unintended consequences of the War on Drugs continue in many ways. A multitude of factors, many of which border on fictitious, led to laws against pot and the subsequent upholding of them, including the notion it served as a “gateway." However, the ban may have backfired and made it easier for actual gateway substances to become more prevalent.
A combination of both well-intentioned approaches - like the infamous D.A.R.E. program - and more dubious forces, resulted in the continued prosecution of cannabis users and labeling of the substance as highly addictive. History is starting to correct itself on this issue, but it may be generations before the damage is fully healed.
The origins of the "gateway" campaign against weed stemmed from data that suggests those who go on to misuse "hard" substances, like coke or H, usually try pot first. However, there is a significant flaw in this conclusion: correlation does not imply causation. Other than the correlation, there’s not much direct evidence supporting the idea.
A closer look at the data unearths serious doubts about the “gateway hypothesis.” While the correlation between herb use and the use of more serious substances remains apparent, the causation behind these numbers is generally explained with multiple other theories that have nothing to do with the gateway theory.
According to the National Academies Press study "Marijuana and Medicine: Assessing the Science Base," "there is no conclusive evidence the effects of [it] are causally linked to the subsequent abuse of other illicit [substances]."
The correlation between the use of cannabis and the overuse of harder substances is the entire foundation of the “gateway hypothesis," but even that crucial piece of evidence is overblown. According to the 2016 National Survey on Drug Use and Health, 24 million Americans age 12 and older regularly used weed. This was roughly 7.4% of the American population at the time.
The percentage of those who use coke or H is minuscule in comparison. Only 1.9 million people over the age of 12, or .5% of the same population, used coke in the same capacity. For H, that number dropped to 475,000, or .14%.
The numbers indicate weed is not a very effective gateway substance. Further evidence demonstrates only 10-20% of those who try any substance - including alcohol and nicotine - become addicted, which means even H itself isn’t that much of a gateway to dependency.
It seems numerous other factors play a much more critical role in this process, including genetic predisposition and environmental factors versus the gateway theory.
The truth behind the gateway hypothesis appears to be less that pot use causes an individual to experiment with harder substances and more so the same factors that influence the use of one substance also affect the use of harder varieties.
Scientific studies have consistently shown childhood issues, socioeconomic conditions, environment, and poverty play a much more direct role in the development of dependency than weed use. Overall, this competing theory to the gateway hypothesis is known as “common liability to addiction.” The National Center for Biotechnology Information notes that:
The data suggest that drug use initiation sequencing, the core [gateway hypothesis] element, is variable and opportunistic rather than uniform and developmentally deterministic. The association between risks for use of different substances, if any, can be more readily explained by common underpinnings than by specific staging.
In contrast, the [common liability to addiction] concept is grounded in genetic theory and supported by data identifying common sources of variation in the risk for specific [dependencies]. This commonality has identifiable neurobiological substrate and plausible evolutionary explanations.
The gateway hypothesis isn’t as old as cannabis use, which goes back at least as far as ancient Greece, but it is about as old as pot prohibition. The origins of the idea first showed up in the ‘30s, when it was known as the “Stepping Stone Theory." This theory relied on a minimal amount of data that claimed 100% of H addicts surveyed started with herb. In 1936, Motion Picture Ventures released Reefer Madness, a propaganda film created to warn youth about the dangers of a 420 lifestyle.
The notion that weed use begets use of harder substances stuck around for decades. As the evidence of correlation stacked up, people started taking it more seriously. In 1984, Robert L. Dupont, the director of the National Institute on Drug Abuse, published a book titled Getting Tough on Gateway Drugs: A Guide for the Family and the theory had its modern moniker.