Depression currently affects almost 15 million people in the US every year. Similar numbers can be found in Europe. Depression and anxiety disorders cost us approximately $42 billion annually, comprising a whopping third of the mental health bill of the country. Is it possible that simple cannabinoids in medical marijuana can help treat this debilitating and costly mental health condition? 
Scientists at the University at Buffalo’s Research Institute on Addictions (RIA) have been studying chronic stress and depression, with a focus on endocannabinoids to cure these ailments. Endocannabinoids are made by our own bodies when we are healthy, and there are similar chemical constituents in medical marijuana.
Endocannabinoids play a vital role in regulating our stress response, because they communicate with the endocrine system to tell it when to release certain hormones, among them stress hormones like cortisol and adrenaline, as well as happy-hormones like oxytocin and serotonin. 
Endocannabinoids also help to regulate our immune system, lipids in our blood, and even body weight by controlling hormones like leptin. As the name suggests, they are similar to the chemicals found in marijuana (Cannabis sativa) and its active ingredient, delta-9-tetrahydrocannabinol (THC).
Forget Marijuana Madness: Could Marijuana Treat Depression?
The researchers at RIA have discovered that medical marijuana’s cannabinoids might be very useful in regulating our ability to overcome symptoms of depression and anxiety caused by chronic stress. Senior research scientist Samir Haj-Dahmane, PhD explains:
“In the animal models we studied, we saw that chronic stress reduced the production of endocannabinoids, leading to depression-like behavior.”
Endocannabinoids affect everything from motor control to how we feel, and as the researchers said:
“Chronic stress is one of the major causes of depression. Using compounds derived from cannabis — marijuana — to restore normal endocannabinoid function could potentially help stabilize moods and ease depression.”
Though the research is still considered preliminary and has been tested only on animals, the results look promising. Haj-Dahmane states:
“. . . we have seen that some people who suffer from post-traumatic stress disorder have reported relief using marijuana.”
The next aims of the research team include finding out if the animals can restore emotional balance without exhibiting increased tolerance to the marijuana extract, cannabidiol (CBD).
The study, co-authored by RIA senior research scientists Roh-Yu Shen, PhD, was funded by a grant from the National Institute of Mental Health. It appeared in the fall issue of the Journal of Neuroscience.