After a California woman avoided prison time last week for fatally stabbing her boyfriend during what prosecutors called an episode of “cannabis-induced” psychosis, questions have been raised about the connection between marijuana and mental illness.

Psychosis refers to a “collection of symptoms that affect the mind, where there has been some loss of contact with reality,” according to the National Institute of Mental Health.

“During an episode of psychosis, a person’s thoughts and perceptions are disrupted and they may have difficulty recognizing what is real and what is not,” the organization’s website notes.

Psychosis can result from a variety of causes, including psychiatric illnesses like schizophrenia, genetic risk, exposure to stressors or trauma — and, as health professionals are seeing more, drug use including marijuana.

Nationwide, studies since 2019 have shown an increase of emergency room visits across the country as a result of cannabis, Dr. David Schreiber, psychiatrist and CEO and co-founder of Compass Health Center, told CBS News.

“What we learned from those studies is a 50% increase of adverse events as a result of cannabis use,” he said.

On a local level, Schreiber said his center, which treats complex psychiatric disorders, has also seen an increase in similar areas.

“What we’ve seen over the last few years is a significant spike in utilization of our co-occurring mental health and substance use disorder programs,” he said.

Why are there increases in these cannabis-related events?

Schreiber pointed to multiple contributing factors.

“This didn’t happen overnight,” he said, citing increases in accessibility to cannabis and cannabis products as one key factor.

“In 2019, we had 11 states that legalize recreational use of cannabis. Today they are 24 states and that number should go up to 29 by the end of this year.”

Potency has also contributed significantly.

“Cannabis today is different than cannabis of previous generations,” he said. “In the 1990s, we had potency concentration of THC and cannabis hovering around 4%. Today, that number is closer to 20% — so five times the greater amount of potency.”

Studies have shown increased potency concentration also correlates with increased adverse events, he said.

And no matter how far it may feel in the past, the COVID pandemic also plays a role, Schreiber said.

“We all want to move on from COVID, but we all have to recognize there is an aftermath — across this country we are seeing spikes in psychiatric conditions, depression, anxiety, OCD, trauma, substance use,” he said. “When people aren’t getting the care that they need for their psychiatric disorders, they tend to self-medicate. And one of the drugs that people tend to use to self-medicate is cannabis.” 

Who should be aware?

While this can affect anyone, young people, whose brains are still developing, are particularly vulnerable — but Schreiber said there is “a lot that we can do,” including keeping the three “E”s in mind:

Educate: He encourages both children and their parents to get information from trustworthy organizations.

Engage: “Once you get that information, it’s important to engage in conversation,” he said. “Engage in conversation with your children, with your loved ones — give them the information they need to help them make healthier decisions.”

Enroll: Get the care you need when you need it, he said. “As parents, we know our children best, and when we see them deviating from the normal behavior or loved ones acting differently or acting in a bizarre way, it’s important for us to get them the care that they need.”

If you or a loved one is experiencing a problem with substance use, help is available via the Substance Abuse and Mental Health Services Administration Helpline at 1-800-662-HELP.