Getting High to Escape the Lows: The Link between Marijuana and Depression

By Michelle Lee | UTS Staff Writer | SQ Online (2015-16)

Over the last couple of decades, marijuana has been listed as a Schedule I drug under the Controlled Substances Act along with lysergic acid diethylamide (LSD) and heroin. Schedule I drugs are drugs that have been defined both as having no accepted medical use and having a high potential for abuse. Hence, these drugs are classified as the most dangerous of drugs, with possible severe psychological or physical dependence. However, since the 1970s, many citizens have come to question whether or not marijuana should remain under Schedule I. Throughout the country, many Americans’ perceptions of this drug have dramatically changed, and within the last decade, over one fifth of states have fully legalized marijuana.

Interestingly, though noted as a very dangerous drug by the US Drug Enforcement Administration (DEA), cannabis has been found to have many medical benefits. Recent research suggests marijuana could be a promising treatment option for various psychological and physical conditions, including depression. Depression affects more than 14 million American adults, making it one of the most common mental disorders in the United States. Therefore, the biological mechanisms and drug targets of depression are currently very attractive areas of research in the scientific world.

In a recent study, neuroscientists from the University of Buffalo’s Research Institute on Addictions discovered that cannabis may alleviate symptoms of depression caused by chronic stress. The study focuses on endocannabinoids, which are cannabis-like chemicals that are naturally made in the body. Endocannabinoids and delta-9-tetrahydrocannabinol (THC), the active component of marijuana, both bind to a protein in the brain called CB1 receptors to modify neuron communication CB1 receptors. These receptors are located throughout the brain, including areas of the amygdala and the cerebral cortex, both of which modulates emotions, such as anxiety and depression.

The neuroscientists discovered that endocannabinoid signaling at the synapses of dorsal raphe nucleus (DRn) serotonin (5-HT) neurons are reduced as a result of stress. Serotonin is a neurotransmitter that influences mood and its imbalance is thought to lead to depression. Serotonergic neurons are largely found in the dorsal raphe, which then projects to areas such as the amygdala. As previous studies have shown that a reduction in the communication of these neurotransmitters leads to depressive effects, the neuroscientists then used compounds derived from cannabis to restore the endocannabinoid function to baseline, potentially mitigating symptoms of depression and stabilizing mood. Although the molecular mechanisms are unknown, marijuana may be the answer the medical world was looking for in regards to curing depression. However, to fully determine the effectiveness of marijuana in a clinical setting, more research is imperative; the association between marijuana and depression is more complicated than meets the eye. Some studies have even shown that regular and heavy marijuana smokers are more likely to be diagnosed with depression, although there isn’t a direct causal relationship between the two. As links between drug use and mental illness require a multidimensional approach, it is important to highlight that there are many biological and social factors that impact the relationship. For example, it may be the case that people with depression use marijuana as a coping mechanism or that regular marijuana users have a heightened sense of emotion and thus are more likely to feel depressed. However, without reliable evidence, the research remains inconclusive.

As of 2015, 20 states have allowed medical use of marijuana, including California. With further research, it is possible that we will see a rise in cannabis being used in the medical world. If this happens, then the DEA may be forced to reconsider how dangerous this Schedule I drug actually is.




Hey I'm Michelle S. Lee and this is my fourth year at UCSD. I'm double majoring in biochemistry/cell biology and psychology and I'm a part of Saltman Quarterly, Flying Samaritans, and Phi Delta Epsilon at UCSD. In my spare time, I love to go jogging, snowboarding, hiking, and shopping.