Regular cannabis use has increased more rapidly among depressed people, and they are less likely to perceive it as risky compared to people who are not depressed, according to a U.S. study.
Researchers examined data collected from nearly 729,000 people aged 12 years and older between 2005 and 2017, including any use of cannabis in the previous months and any depression experienced in the previous year.
In the final year of the study, about 19% of people with depression reported using at least some cannabis, compared to 8.7% of those with no recent history of depression. In 2005, about 10.2% of people with depression and 5.7% of people without depression used the drug.
The proportion of depressed people who perceived cannabis use as a risk behavior also dropped from 41% to 17% over the study period, compared to a drop from 52% to 33% among non-depressed people, according to the Addiction magazine report.
“This perception of risk decreases more rapidly in people with depression,” said Renee Goodwin of Columbia University in New York City, the study’s lead author.
“People with depression who perceive little or no risk associated with use have a much higher prevalence of cannabis use, compared to those who perceive higher associated risks,” Goodwin said in an email.
Current cannabis use is highest among people aged 18 to 25 years suffering from depression, at almost 30%, according to the study. Use was also common among depressed males, blacks and unmarried people, at about 23 percent for each group.
In fact , the study was not designed to determine whether or how depression might influence the frequency of cannabis use, or how people think about the risk of regular cannabis use.
One limitation of the study is that the researchers relied on study participants to honestly report any symptoms of cannabis use or depression; they did not have laboratory tests for drug use or medical records to confirm a mental health diagnosis.
The researchers were also unable to determine whether the legalization of cannabis may have had an impact on the proportion of people who use the drug or on participants’ perceptions of its safety, the study team notes.
“Some people think that drug use is a form of self-medication for depression, or an attempt to self-medicate the symptoms of depression,” said Goodwin.
During the study period, most U.S. states legalized either medicinal or recreational use of cannabis or both, and it is also possible that this may have contributed to a reduction in risk perception, Goodwin added.
“There is anecdotal evidence that some people perceive cannabis as less risky than psychiatric drugs, and with legalization, (cannabis) may be cheaper and more available and associated with less stigma,” Goodwin said.
However, people need to understand that cannabis may actually be riskier for people suffering from depression.
So there is no evidence to suggest that cannabis use relieves the symptoms of depression, except temporarily, and there is evidence to suggest that cannabis use can worsen or prolong depression,” Goodwin said. “Historically, patients in treatment or recovery from depression have been advised to avoid cannabis use.”