The youngest patient with cannabis-induced psychosis (CIP) whom Karen Randall, DO, has treated was a 7-year-old boy. She remembers the screaming, the yelling, the uncontrollable rage.
Dr. Randall is an emergency medicine physician at Southern Colorado Emergency Medicine Associates, a group practice in Pueblo, Colo. She treats youth for cannabis-related medical problems in the emergency department an average of two or three times per shift, she said.
Colorado legalized the recreational use of cannabis for adults older than 21 in 2012. Since then, Dr. Randall said, she has noticed an uptick in cannabis use among youth, as well as an increase in CIP, a syndrome that can be indistinguishable from other psychiatric disorders such as schizophrenia in the emergency department. But the two conditions require different approaches to care.
“You can’t differentiate unless you know the patient,” Dr. Randall said in an interview.
In 2019, 37% of high school students in the United States reported ever using marijuana, and 22% reported use in the past 30 days. Rates remained steady in 2020 following increases in 2018 and 2019, according to the Centers for Disease Control and Prevention.
The CDC also found that 8% of 8th graders, 19% of 10th graders, and 22% of 12th graders reported vaping marijuana in the past year.
Clinicians in states where recreational marijuana has been legalized say they have noticed an increase in young patients with psychiatric problems – especially after consumption of cannabis products in high doses., which often begin to present in adolescence.
How to differentiate
CIP is characterized by delusions and hallucinations and sometimes anxiety, disorganized thoughts, paranoia, dissociation, and changes in mood and behavior. Symptoms typically last for a couple hours and do not require specific treatment, although they can persist, depending on a patient’s tolerance and the dose of tetrahydrocannabinol (THC) they have consumed. Research suggests that the higher the dose and concentration of the drug consumed, the more likely a person will develop symptoms of psychosis.
Diagnosis requires gathering information on previous bipolar disorder or schizophrenia diagnosis, prescriptions for mental illness indications, whether there is a family history of mental illness, and whether the patient recently started using marijuana. In some cases, marijuana use might exacerbate or unmask mental illness.
If symptoms of CIP resolve, and usually they do, clinicians can recommend that patients abstain from cannabis going forward, and psychosis would not need further treatment, according to Divya Singh, MD, a psychiatrist at Banner Behavioral Health Hospital in Scottsdale, Ariz., where recreational cannabis became legal in 2020.
“When I have limited information, especially in the first couple of days, I err on the side of safety,” Dr. Singh said.
Psychosis is the combination of symptoms, including delusions, hallucinations, and disorganized behavior, but it is not a disorder in itself. Rather, it is the primary symptom of schizophrenia and other chronic psychiatric illnesses.
Schizophrenia can be diagnosed only after a patient presents with signs of disturbance for at least 6 months, according to guidelines in the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition. Dr. Singh said a diagnosis of schizophrenia cannot be made in a one-off interaction.
If the patient is younger than 24 years and has no family history of mental illness, a full recovery is likely if the patient abstains from marijuana, he said. But if the patient does have a family history, “the chances of them having a full-blown mental illness is very high,” Dr. Singh said.
If a patient reports that he or she has recently started using marijuana and was previously diagnosed with bipolar disorder or schizophrenia, Dr. Singh said he generally prescribes medications such as lithium or quetiapine and refers the patient to services such as cognitive-behavioral therapy. He also advises against continuing use of cannabis.
“Cannabis can result in people requiring a higher dose of medication than they took before,” Dr. Singh said. “If they were stable on 600 mg of lithium before, they might need more and may never be able to lower the dose in some cases, even after the acute episode.”