A new study finds ketamine use increased 40% in the United States between 2021 and 2022.

The increase occurred mainly among young adults ages 26 to 34 and those with a college degree, HealthDay reports.

Ketamine is used as a recreational drug as well as for medical purposes. As a recreational substance, it can cause a person to feel disconnected from reality — like they are in a dreamlike state. In recent years, it has gained popularity as a potential mental health treatment, particularly for severe depression. It may also be useful for treating substance use disorders. However, its benefits, dosage and long-term effects are still under investigation, and it may be risky to use without medical supervision, according to Partnership to End Addiction.

The new study found the increase between 2021 and 2022 follows a nearly 82% increase in ketamine use from 2015 to 2019. Researchers found the increase in ketamine use during the 2010s was largely associated with people with depression. The more recent increase occurred largely in people without depression.