Annual overdose deaths, fueled by fentanyl, reached a new record high in the 12-month period ending October 2021, according to new government data.

The Centers for Disease Control and Prevention (CDC) reported an estimated 105,752 people died from overdoses during that period. Approximately two-thirds of those deaths involved fentanyl and other synthetic opioids, CNN reports.

“Fentanyl, even at very, very small quantities, is lethal for most people,” said Katherine Keyes, an associate professor at the Columbia University Mailman School of Public Health whose research focuses on psychiatric and substance use epidemiology. “It’s just an incredibly potent opioid.”

The CDC report found overdose deaths increased in all but four states – New Hampshire, Hawaii, Delaware and Wyoming – compared with the previous year. Overdose deaths from methamphetamine and other psychostimulants increased almost 40% from the previous year.