Coronavirus (COVID-19): Important information from Sharp
Doctor's office
Enter your doctor's name to get office information.
Find labs in your network
Enter your primary care doctor's name to find labs in your network.
Find urgent care centers in your network
Enter your primary care doctor's name to find urgent care centers in your network.
Driving Directions
Update Information
Forgot Password

Please enter your e-mail address.

Sharp Health News

Marijuana and mental illness

Sept. 25, 2019

Marijuana and mental illness

Marijuana is easier than ever to access — 11 states (including California) and the District of Columbia have legalized recreational use for adults older than age 21, and 22 more states have legalized medicinal marijuana.

Although the drug has been approved for medicinal use in many places, research is still ongoing to determine its therapeutic benefits. In fact, some research shows a connection between marijuana use and early onset of psychiatric disorders, particularly in those genetically predisposed to mental illness.

While there is no evidence that marijuana actually causes mental illness, it has been shown to worsen symptoms in those living with psychiatric conditions. Marijuana has the immediate effects of inducing paranoia and anxiety. Subtle effects of reduced motivation and depressed mood may not be as obvious.

Marijuana and psychiatric medications
The marijuana of today is much more potent than what was available in decades past, and its mind-altering effects can cause people to experience intense panic and anxiety, even if they are not living with mental illness. However, for those living with psychiatric conditions — especially those managing their condition with medication — the effects can be much worse.

“There has always been a known association with marijuana use and severe psychiatric illness. For instance, people with psychotic disorders like schizophrenia have some kind of substance abuse disorder about 50% of the time,” says psychiatrist Dr. Brian Miller, clinical director at Sharp Grossmont Hospital’s Behavioral Health Center. “In the past, we didn’t know if the relationship was causal, but increasing evidence has shown substance abuse, including marijuana, can provoke or exacerbate psychiatric illness.”

How marijuana affects the brain
Marijuana binds to cannabinoid receptors in the brain to produce a variety of effects including euphoria, intoxication, and memory and motor impairment. These cannabinoid receptors are critical for brain development and are part of the endocannabinoid system, impacting the formation of brain circuits important for decision-making, mood and responses to stress. Higher doses of THC — the psychoactive ingredient in marijuana — are more likely to produce anxiety, agitation, paranoia and psychosis.

“Marijuana is similar to alcohol, nicotine and caffeine in that all of these substances are widely used for the pleasant and rewarding effects,” explains Dr. Miller. “However, there are risks of overuse, addiction and complicating factors. As the amount and frequency a person uses goes up, so does the chance they will suffer adverse consequences.”

Impact of increased use
While it is difficult to measure the widespread effects of the legalization of marijuana, there has been a clear effect on emergency room visits for the acute adverse effects of the drug. New users particularly may not appreciate the potent mind-altering effects and may develop intense panic and dysphoria. There has been a general but misguided attitude that if it’s legal, it can’t be too bad, resulting in more people trying marijuana for the first time.

“Despite being legal, marijuana is not a benign substance,” says Dr. Miller. “Some people will choose to use marijuana similarly to alcohol or other mood-altering substances. However, just as someone with an alcohol use disorder should refrain from drinking, many with preexisting psychiatric disorders should avoid marijuana entirely.”

You might also like:

Choose the doctor who's right for you.

At Sharp, we make it easy to find an exceptional doctor — right where you live and work.

All Categories
Contact Sharp HealthCare
Call us


If this is a life- or limb-threatening emergency, please call 911 immediately.

Email us

Please do not use this form to convey personal or medical information.

How would you like to be contacted?
Date of birth

Find other numbers

View our phone directory

What's This?

These important numbers are located on your billing statement.

Find your Sharp Rees-Stealy account number

Find your Sharp Rees-Stealy account number

Find your Sharp hospital account number

Find your Sharp hospital account number

Find your SharpCare account number

Find your SharpCare account number
What's GDPR?

The General Data Protection Regulation (GDPR) governs the processing of personal information gathered from individuals while they are in the European Union (EU) and parts of the EEA (European Economic Area, which currently includes Iceland, Lichtenstein and Norway).

We are sorry, but we are unable to process hospital price estimates if you live or are travelling within the EU or affiliated nations.

To learn more, call us at 858-499-5901.

What's This?

Many surgery and procedure names sound similar. If possible, please provide the current procedure terminology (CPT) code, which can be found on the order from your doctor.

If you cannot provide the CPT code, please contact your doctor's office for the CPT or a detailed description of services.