“Soft” drugs cause addiction.
Gateway drugs can be described as “introductory level” substances that can lead to the use of harder, more habit-forming drugs over time. These milder substances — such as alcohol and marijuana — are usually accessible to teens and young adults, and allow them to become familiar with the sensations of being intoxicated.
While marijuana has earned a reputation as a gateway drug, the substance most likely to introduce a teenager to hard drugs is alcohol.
The gateway theory became popular in the 1980s and relies on the idea that, if young people become comfortable using mild substances like alcohol, they’re more likely to experiment with drugs that are riskier and more addictive. Also, as teens and other young users develop a tolerance for certain substances, they’re more likely to use greater quantities and develop addiction.
Does the gateway theory mean a teenager who has tried marijuana is destined to become addicted to heroin down the road? Not necessarily. There are many factors that contribute to someone’s likelihood of developing a substance use disorder, including genetics, environment and more. But the age at which a person begins using habit-forming substances — even mild ones — can be a predictor of their capacity for addiction later in life. For instance, a 2016 Surgeon General’s Report indicates that teens who drink alcohol before the age of 15 are four times more likely to develop an addiction than those who wait until age 20 to drink.
In the context of the brain’s growth and development, the gateway theory makes sense. When alcohol and other drugs disrupt brain development, especially before the age of 25, it can pose a greater risk than at other ages. Adolescence in particular is a time of adjustment, experimentation, and spontaneous risk-taking. That’s why it’s especially important to intervene quickly, even when the substances young people are using may be mild.