Young adults who use cannabis – either sporadically, daily, or those who have cannabis use disorder – have a significantly increased risk for suicidal thoughts and actions, according to U.S. national drug survey data.
The risks appear greater for women than men and remained regardless of whether the individual was depressed.
“We cannot establish that cannabis use caused increased suicidality,” Nora Volkow, MD, director, National Institute on Drug Abuse (NIDA), told this news organization.
“However, it is likely that these two factors influence one another bidirectionally, meaning people with suicidal thinking might be more vulnerable to cannabis use to self-medicate their distress, and cannabis use may trigger negative moods and suicidal thinking in some people,” said Dr. Volkow.
“It is also possible that these factors are not causally linked to one another at all but rather reflect the common and related risk factors underlying both suicidality and substance use. For instance, one’s genetics may put them at a higher risk for both suicide and for using marijuana,” she added.
The study was published online June 22 in JAMA Network Open.
Marked increase in use
Cannabis use among U.S. adults has increased markedly over the past 10 years, with a parallel increase in suicidality. However, the links between cannabis use and suicidality among young adults are poorly understood.
NIDA researchers sought to fill this gap. They examined data on 281,650 young men and women aged 18 to 34 years who participated in National Surveys on Drug Use and Health from 2008 to 2019.
Status regarding past-year cannabis use was categorized as past-year daily or near-daily use (greater than or equal to 300 days), non-daily use, and no cannabis use.
Although suicidality was associated with cannabis use, even young adults who did not use cannabis on a daily basis were more likely to have suicidal thoughts or actions than those who did not use the drug at all, the researchers found.
Among young adults without a major depressive episode, about 3% of those who did not use cannabis had suicidal ideation, compared with about 7% of non-daily cannabis users, about 9% of daily cannabis users, and 14% of those with a cannabis use disorder.
Among young adults with depression, the corresponding percentages were 35%, 44%, 53%, and 50%.
Similar trends existed for the associations between the different levels of cannabis use and suicide plan or attempt.
Women at greatest risk
Gender differences also emerged. than men with the same levels of cannabis use.
Among those without a major depressive episode, the prevalence of suicidal ideation for those with versus without a cannabis use disorder was around 14% versus 4.0% among women and 10% versus 3.0% among men.
Among young adults with both cannabis use disorder and major depressive episode, the prevalence of past-year suicide plan was 52% higher for women (24%) than for men (16%).
“Suicide is a leading cause of death among young adults in the United States, and the findings of this study offer important information that may help us reduce this risk,” lead author and NIDA researcher Beth Han, MD, PhD, MPH, said in a news release.
“Depression and cannabis use disorder are treatable conditions, and cannabis use can be modified. Through better understanding the associations of different risk factors for suicidality, we hope to offer new targets for prevention and intervention in individuals that we know may be at high risk. These findings also underscore the importance of tailoring interventions in a way that takes sex and gender into account,” said Dr. Han.
“Additional research is needed to better understand these complex associations, especially given the great burden of suicide on young adults,” said Dr. Volkow.