The Effectiveness of Cannabis Flower for Immediate Relief from Symptoms of Depression

Yale J Biol Med. 2020 Jun 29;93(2):251-264. eCollection 2020 Jun.


Objective: Scientific research on how consumption of whole, natural Cannabis flower affects low mood and behavioral motivations more generally is largely nonexistent, and few studies to date have measured how common and commercially available Cannabis flower used in vivo may affect the experience of "depression" in real-time. Methods: We observed 1,819 people who completed 5,876 cannabis self-administration sessions using the ReleafApp™ between 06/07/2016 and 07/08/2019, with the goal of measuring real-time effects of consuming Cannabis flower for treating symptoms of depression. Results: On average, 95.8% of users experienced symptom relief following consumption with an average symptom intensity reduction of -3.76 points on a 0-10 visual analogue scale (SD = 2.64, d = 1.71, p <.001). Symptom relief did not differ by labeled plant phenotypes ("C. indica," "C. sativa," or "hybrid") or combustion method. Across cannabinoid levels, tetrahydrocannabinol (THC) levels were the strongest independent predictors of symptom relief, while cannabidiol (CBD) levels, instead, were generally unrelated to real-time changes in symptom intensity levels. Cannabis use was associated with some negative side effects that correspond to increased depression (e.g. feeling unmotivated) in up to 20% of users, as well as positive side effects that correspond to decreased depression (e.g. feeling happy, optimistic, peaceful, or relaxed) in up to 64% of users. Conclusions: The findings suggest that, at least in the short term, the vast majority of patients that use cannabis experience antidepressant effects, although the magnitude of the effect and extent of side effect experiences vary with chemotypic properties of the plant.

Keywords: C. sativa; Cannabis; antidepressants; cannabidiol; depression; marijuana; stress; tetrahydrocannabinol.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Affect / drug effects*
  • Antidepressive Agents* / administration & dosage
  • Antidepressive Agents* / adverse effects
  • Cannabidiol / blood
  • Depression* / blood
  • Depression* / diagnosis
  • Depression* / drug therapy
  • Dronabinol / blood
  • Emotions / drug effects
  • Female
  • Humans
  • Male
  • Medical Marijuana* / administration & dosage
  • Medical Marijuana* / adverse effects
  • Motivation / drug effects*
  • Self Administration / methods
  • Treatment Outcome
  • Visual Analog Scale


  • Antidepressive Agents
  • Medical Marijuana
  • Cannabidiol
  • Dronabinol