Western-led research suggests marijuana use may pose a greater risk to brain function if you are currently, or have in the past, suffered from depression. Led by Department of Psychiatry professor Dr. Elizabeth Osuch, these findings may have implications for the clinical treatment of depression.
The study was published in the September issue of Frontiers in Psychiatry.
“We know recreational use of marijuana is increasing in adolescents. There is also a growing association between marijuana use and mood disorders,” said Osuch, a Lawson Health Research Institute scientist. “What we were interested in finding out was how marijuana use affects reward-processing in the brain in youth with depression.”
Osuch serves as medical director of the First Episode Mood and Anxiety Program (FEMAP), which helps older teens and young adults (age 16-25) with emotional concerns that fall into the categories of mood and/or anxiety disorders. In that capacity, she has encountered a number of depressed patients who use marijuana frequently. Those patients can see the drug as a “quick fix” to their depression.
In those patients, however, there seemed to be a correlation between the drug’s use and their depression. But in order to determine if these effects were additive, Osuch needed a quick snapshot of the brain.
She used functional magnetic resonance imaging to evaluate brain activity in youth who used marijuana, but were never depressed; youth living with depression who used marijuana; in comparison with youth living with depression who did not use marijuana. Her analysis showed brain abnormalities caused by marijuana use, in combination with depression, but not in either alone.
“Indeed, the combination of marijuana use and depression is sort of a ‘double whammy.’ If you’re trying to treat it (depression) with marijuana, you’re barking up the wrong tree,” Osuch said.
“It’s a quick fix, you feel better right away, but the problem is, it doesn’t solve the problem in the long run. My evidence suggests it’s actually making the brain pathology of depression worse,” she said. “The reason they (patients) end up in my office is because the temporary fixes stop working – it does all the time.”
Alternatives to marijuana are available for the treatment of depression, Osuch said, including anti-depressant medications and psychotherapeutic treatments. The problem for sufferers is access, she said.
“There are far more people with depression out there than there are treatment providers. That’s a whole other problem,” Osuch said.
London is doing “much better” with this since she began at FEMAP. Times for young adults to see a psychiatrist has dropped from almost two years to less than three months.
Osuch believes the next step is educating the public, which increasingly sees marijuana as harmless.
“Some people have suggested marijuana may be an effective treatment for depression. Our results suggest this conclusion is premature,” she said. “These findings suggest depressed youth increase their risk of functional brain abnormalities through the use of marijuana and that more research into these effects is needed.”
Osuch is looking to undertake a more longitudinal study to see if brain changes are actually associated with the extent of marijuana use in the context of depression.
