By Pat Anson, PNN Editor

Consuming dried cannabis flowers with high levels of THC significantly reduces symptoms of depression, according to a new study of over 1,800 cannabis consumers.

The study findings, published in the Yale Journal of Biology and Medicine, is the latest research derived from the Releaf App, a free mobile software program that collects self-reported, real-time information from people on their use of cannabis and its effect on chronic pain, depression and over two dozen other medical conditions.

This particular study excluded the use of cannabis edibles, lotions and oils, and focused solely on cannabis buds that were smoked or inhaled through a vaporizer.

Over 95% of participants in the study reported a decline in depression within hours of ingesting cannabis, with an average reduction in symptom intensity of nearly 4 points, based on a numerical zero to 10 depression scale.

Relief from depression did not vary by the strain of cannabis consumed, but flowers with high levels of tetrahydrocannabinol (THC) were the strongest predictors of symptom relief. THC is the main psychoactive ingredient in cannabis. Levels of cannabidiol (CBD) were generally unrelated to changes in depression.

“Almost all patients in our sample experienced symptom relief from using Cannabis to treat depression and with minimal evidence of serious side effects in the short run,” researchers reported.

“One of the most clinically relevant findings from this study was the widely experienced relief from depression within 2 hours or less. Because traditional antidepressants have times-to-effect in weeks, short-term Cannabis use might be a solution to these delays in treatment or could be used to treat acute episodes associated with suicidal behavior and other forms of violence.”

Prescription drugs used to treat depression include sedatives such as benzodiazepines and antidepressants such as selective serotonin-reuptake inhibitors and tricyclics, as well as anticonvulsant medicines. Most normally take several weeks or months to cause significant relief and have potential side effects such as sedation and suicidal thoughts. Benzodiazepines have become particularly difficult for many pain patients to obtain if they are also prescribed opioid medication.

Medical marijuana is legal in 33 U.S. states and Washington, DC, but depression is not generally recognized as an approved condition under state-regulated medical marijuana programs.

“With no end to the depression epidemic in site, and given the limitations and potential severe negative side effects of conventional antidepressant medications, there is a real need for people to be able to treat mood disturbances with natural, safe, and effective medications, and cannabis checks off all three boxes,” co-author Jacob Vigil, PhD, a University of New Mexico psychology professor, told Forbes.

An earlier study by Vigil using data from the Releaf App found that cannabis flowers rich in THC reduced pain levels an average of three points on a 0 to 10 pain score. Those who ingested cannabidiol (CBD) did not experience similar pain relief.

Another study derived from ReLeaf App data found that cannabis can provide relief from a wide range of symptoms associated with chronic pain, including insomnia, seizures, anxiety and fatigue.

A significant weakness of these studies is that they rely on cannabis users to subjectively self-report their symptoms outside of a clinical setting. There is also no control group or way to measure the quality or quantity of the cannabis they are ingesting.