We have completed maintenance on DiscoverMagazine.com and action may be required on your account. Learn More

What Are "Hard" and "Soft" Drugs?

The line between the two might not be where you'd think.

Neuroskeptic iconNeuroskeptic
By Neuroskeptic
Jun 27, 2017 7:35 PMMay 19, 2020 1:50 AM
Pills and Marijuana in Prescription Drug Bottles - Shutterstock
(Credit: gabriel12/Shutterstock)


Sign up for our email newsletter for the latest science news

new study examines the blurry distinction between “hard” and “soft” drugs.

The “hardness” of drugs is a concept that makes intuitive sense, but is difficult to put into precise terms. “Hard” drugs are those which are viewed as more addictive, more potent and more toxic than the comparatively benign “soft” variety. The concept has a normative aspect: “hard” drugs are bad, and you should avoid them, even if you use soft drugs.

In the new paper, Slovakian researchers Peter Janik et al. tried to quantify the perceived “hardness” of various drugs, from alcohol to LSD and cocaine. The authors counted the number of times each substance was listed as a “hard” or a “soft” drug across 132 peer-reviewed research papers that gave at least one such example, published between 2011 and 2015.

The results contained a few surprises:


Cannabis was the most frequently cited “soft” drug while cocaine and heroin were the leading “hard” ones, which is not unexpected. However, I was surprised that hallucinogens such as LSD and psilocybin mushrooms were frequently listed as “hard” drugs, given that these substances are not considered to be addictive or especially toxic.

That cocaine was twice listed as a soft drug, and methamphetamine was also listed as such once, is also a little odd. Cannabis was unexpectedly called a hard drug four times.

Then we come to alcohol, which was listed as a “soft” drug 42 times, and as a “hard” one 3 times. This was surprising to me, as I didn’t expect to see alcohol listed very often in either category. Most people don’t consider alcohol a “drug”, although of course it is one, and if I had to name a “soft drug”, alcohol wouldn’t come to mind.

And how “soft” is alcohol really? Janik et al. note that in terms of toxicity and addictive potential, alcohol is more problematic than many of the “hard” drugs. Presumably, its legal status and widespread use has softened its image.

Janik et al. conclude that “hardness” is a vague concept and that scientists should probably stop using the terms “soft” and “hard”:

Explanations for categorization as ‘hard’ or ‘soft’ are rarely given. ‘Hardness’ or ‘softness’ may refer to different aspects of psychoactive substances and can be perceived differently when comparing only two or a small number of specific drugs rather than the entire spectrum of substances… citations supporting categorization were missing in 90% of the articles.

To avoid confusion in the future, we recommend not using the terms “ hard drugs” and “ soft drugs” in scientific publications unless adequately clarified and precisely specified by authors.

1 free article left
Want More? Get unlimited access for as low as $1.99/month

Already a subscriber?

Register or Log In

1 free articleSubscribe
Discover Magazine Logo
Want more?

Keep reading for as low as $1.99!


Already a subscriber?

Register or Log In

More From Discover
Recommendations From Our Store
Shop Now
Stay Curious
Our List

Sign up for our weekly science updates.

To The Magazine

Save up to 40% off the cover price when you subscribe to Discover magazine.

Copyright © 2024 Kalmbach Media Co.