- People with underlying mental illness who have a pre-existing risk for suicide ideation may be more likely to use marijuana to treat their symptoms.
- It’s unclear if marijuana directly increases a person’s risk of mental illness and suicide ideation.
- Experts say more research is needed to better understand the link.
A new study from the National Institute on Drug Abuse (NIDA) found that marijuana use is associated with a greater risk of experiencing suicidal thoughts.
According to the findings, which published in JAMA Network Open this week, even people who used marijuana sporadically were more likely to have depression than those who didn’t use marijuana at all.
The study adds to growing evidence suggesting a link between cannabis use and mood disturbances and attempts at self harm.
But health experts say the link is not so simple.
People with underlying mental illness who have a pre-existing risk for suicide ideation may be more likely to use marijuana to treat their symptoms.
There are also likely other contributing factors — including genetic and environment factors — that may increase the risk for mental illness and suicide ideation.
Many people with mental illness appear to benefit from marijuana; however, more negative outcomes have been recorded among people with severe psychiatric disorders like schizophrenia and bipolar disorder who use marijuana.
It’s unclear if marijuana directly increases a person’s risk of mental illness and suicide ideation or if the relationship is correlational. More research is needed to better understand the link.
Over 281,000 people between the ages of 18 and 35 participated in the National Surveys on Drug Use and Health from 2008 through 2019.
The participants answered questions related to marijuana use, depression, suicidal thoughts, plans, and attempted suicide.
The researchers evaluated four different groups — those who used no marijuana, people who used marijuana daily, people who used marijuana non-daily, and individuals with cannabis use disorder.
They found that people who used marijuana — sporadically or frequently — faced a greater risk of suicide ideation compared to those who did not use marijuana.
According to the findings, the risk remained even in people who weren’t experiencing depression.
Of the participants without depression, 9 percent of people who used marijuana daily and 7 percent of people using marijuana non-daily experienced suicide ideation compared to 3 percent who did not use marijuana.
Of the participants with depression, 35 percent of people who did not use marijuana experienced suicide ideation.
About 44 percent of people who used marijuana not on a daily basis and 53 percent of those who used marijuana daily experienced suicide ideation.
Women who used marijuana also appeared to have a greater associated risk of suicidal ideation than men who used marijuana.
“While we cannot establish that cannabis use caused the increased suicidality we observed in this study, these associations warrant further research, especially given the great burden of suicide on young adults,” NIDA Director Dr. Nora Volkow, the senior author of this study, said in a statement. “As we better understand the relationship between cannabis use, depression, and suicidality, clinicians will be able to provide better guidance and care to patients.”
According to Dr. Deepak Cyril D’Souza, a professor of psychiatry at Yale University School of Medicine, interest in using cannabis to treat mental illness has been growing.
Research is in the early phases, and scientists are still learning about if and how marijuana could be used to treat psychotic disorders, mood disorders, and anxiety disorders.
It’s unclear if the relationship between marijuana use and suicide ideation is purely correlational, or if causation might be at play.
“Most people who use cannabis are not suicidal and most people who have attempted suicide may not have used cannabis, so cannabis is neither necessary nor sufficient to ‘cause’ suicide or mood disorders,” D’Souza said.
But growing evidence suggests there is a link between marijuana use and mood disturbances.
For example, a study from earlier this year found that adolescent cannabis consumption was associated with greater risk of experiencing depression and suicidal behavior later in life, D’Souza pointed out.
Cannabis use may be a contributing factor, according to D’Souza, but there are likely several other factors, including environmental and genetic factors, that contribute to a person’s risk of mood disorders and suicide.
Dr. Benjamin Caplan, a board-certified family medicine physician based in Chestnut Hill, MA who treats patients with cannabis, says many patients with mental illness respond positively to marijuana but “occasionally those consuming inappropriate doses or taking cannabis in unfavorable settings do not respond well.”
Data has shown that marijuana use has been linked to more negative outcomes — including increased rates of relapse, emergency room visits, hospitalization, legal troubles, homelessness and worse prognosis — in patients with severe mental illness, such as schizophrenia and bipolar disorder, according to D’Souza.
The link between cannabis use and risk of depression and suicide is poorly understood.
“The fact that suicide occurs in association with some treatment choices is not necessarily best explained as caused directly by the treatment choices themselves,” Caplan, who has conducted research on cannabis’s impact on health, said.
“Clearly, further work is necessary to tease the complex association between cannabis use, mood disorders and suicide,” says D’Souza.
Those experiencing suicide ideations should reach out for help or find a therapist if possible.
Caplan suggests immediately contacting friends, family members or the national suicide prevention hotline (800-273-8255).
“Countless resources are eager to help anyone find a way out of overbearing dark times or seemingly helpless circumstances. Everyone deserves one more chance for an improved reality, and it can be as simple as a quick phone call,” Caplan said.
New research suggests that marijuana use is associated with a greater risk of experiencing suicidal thoughts, but health experts say the link is not so simple. It’s unclear if the link is purely correlational, or if there is some level of causation. Many people with mental health issues appear to benefit from marijuana; however, patients with severe psychiatric disorders who use marijuana have been associated with worse outcomes. More research is needed to understand the link between cannabis use and mental health and determine if and how marijuana should or shouldn’t be used to treat mental health disorders.