In the 1980s, the American government proclaimed marijuana to be a gateway drug, the first step on a path to serious drug abuse.  Certainly, many people experiment with marijuana as teens, with marijuana leading to harder drugs for some, but not all, people who try it.  But those individuals who do become addicted to hard drugs have to start somewhere, and they often begin by abusing marijuana or other “gateway drugs” such as alcohol, or more recently, ADHD medications such as Adderal.  As for marijuana being a gateway drug, the facts support the theory that, for some people, gateway drugs open the doors to a long term addiction.

What is a Gateway Drug?

A gateway drug is a “low” or “soft” drug, such as marijuana, alcohol, or nicotine, that introduces a person to drug use and opens the door to harder drugs.  These drugs stimulate the dopamine pathway, one of the reward centers in the brain, providing the user with a sense of pleasure.  Stimulating this reward pathway trains the brain to expect future triggers and rewards, priming the brain for future drug abuse.  In this phenomenon, which is known as cross-sensitization, once the brain becomes receptive to the effects of one drug, it will show a more dramatic response to other drugs.  Studies in rats confirm this effect: rats that have been exposed to THC, the active component in marijuana, show increased reactivity not only to THC but to other drugs such as morphine.  For decades, marijuana was advertised as the main gateway drug, but more recently, ADHD medications such as Adderall have been implicated as gateway drugs as well.  With the rise in use of prescription stimulants for ADHD, Adderall and other, similar drugs have become more readily available to teens and college students.  Abuse of these drugs can be a gateway to abuse of other prescription drugs.

The Science Behind The Gateway Drug Theory

There is a wealth of scientific evidence to support the gateway drug theory, explaining how gateway drug use prepares the brain for abuse of hard drugs.  Studies in rats suggest that alcohol use can prime the brain for future cocaine abuse.  Rats who were exposed to alcohol were more likely to push a lever that released cocaine, but rats exposed to cocaine were not more likely to consume alcohol.  The fact that alcohol use made cocaine use more likely, but not the other way around, indicates that alcohol prepares the brain for cocaine, the very definition of a gateway drug.  Other studies explain why this may happen: alcohol can turn off the activity of two genes that normally inhibit cocaine’s effects on the brain.  In effect, drinking alcohol opens the brain up to fully feel the high of cocaine.  Similar studies show the same effect between nicotine and cocaine use in mice: mice exposed to nicotine were more likely to use cocaine, but not vice versa, showing that nicotine acts as a gateway drug for cocaine.

These rodent studies show how gateway drugs operate in the brain, and some studies in humans support the idea of marijuana leading to harder drugs.  According to a long-term study by the National Institute on Drug Abuse, adults who used marijuana were more likely to develop an alcohol abuse disorder within three years, and adults who already had an alcohol use disorder and used marijuana were more likely to develop a worse alcohol abuse disorder.  These studies show that marijuana can be a gateway drug, but other studies demonstrate that it is not always a gateway drug.  People who take prescription opiate painkillers for chronic pain are able to reduce their opiate usage by using marijuana, reducing their overall “hard drug” use.  In Japan, marijuana use is less prevalent than in the United States, and 83% of hard drug users there did not begin with marijuana use.  This evidence suggests that other theories can explain illicit drug abuse.

One of these theories is the Common Liability theory, which states that certain people are more likely to become addicted to drugs and alcohol, for a variety of biological, personal, and environmental reasons.  This theory also explains why some people can experiment with marijuana without becoming addicted, simply because they are inherently less likely to develop an addiction.  The Common Liability theory and the Gateway Drug Theory are not necessarily at odds; they simply explain different aspects of the data.  The Gateway Drug theory explains that for people who do try drugs and alcohol, the order in which they try them matters. Using marijuana or alcohol first really does make the brain more susceptible to the impact of harder drugs later on.  The Common Liability theory explains why some people never become addicted, no matter which drug they try first.

Case Study: Luke Wardle

Luke Wardle opens up in an interview, discussing his own struggles with drug abuse and his feelings on whether or not marijuana is a gateway drug.  Luke began using marijuana very young, around age 13, and immediately began selling it as well, in small amounts to friends.  Over time, he began using and selling amphetamines (speed), then cocaine, and finally heroin.  By the age of 19, Luke had what he describes as a very bad cocaine habit that made him paranoid, anxious, and depressed.  Much as he wanted to quit cocaine specifically, and drugs in general, he was unable to do so, and progressed to heroin use.  His heroin habit made him so sick that he stopped selling drugs altogether, allowing heroin use to consume his life.  Eventually, Luke managed to clean up and maintain his sobriety, but his experiences have provided him with a unique perspective on why marijuana is a gateway drug.

Luke’s experience is a classic example of marijuana as a gateway drug.  He began with marijuana, then moved from marijuana to harder drugs.  He believes that marijuana is a gateway drug, not just because of its effects on the brain, but because of the situations you may find yourself in when using marijuana,  He states that marijuana “opens you up to other people who are involved in other, harder substances.”  He himself started out with marijuana, what he calls a “low” drug, with marijuana leading to harder drugs, until he could no longer function and sought help.  If he had not started abusing marijuana, Luke believes, he would never have progressed on to more illicit substances.

In addition to his own experience with drug use, Luke has witnessed the damage caused by drug abuse on the lives of friends and family.  His stepbrother, David, has suffered long-term mental health issues as a result of his drug use.  A close friend, who started out using marijuana, developed mental health problems that made him very violent.  The friend now has to be medicated into what Luke describes as a “zombie-like” state and is currently living in a mental health facility.

Luke’s experience illustrates that marijuana can be a gateway drug, and highlights the dangers of experimenting with drugs that some people consider to be harmless.  If you or someone you love is concerned about drug abuse, call our toll-free number today.  Help is available.