Pro

Thomas F. Denson, PhD, Professor of Psychology at the California State University at Long Beach, and Mitch Earleywine, PhD, Associate Professor of Psychology at the State University of New York at Albany, wrote the following in their Apr. 2006 study titled "Decreased Depression in Marijuana Users," published in Addictive Behaviors:

“Those who consume marijuana occasionally or even daily have lower levels of depressive symptoms than those who have never tried marijuana. Specifically, weekly users had less depressed mood, more positive affect, and fewer somatic complaints than non-users. Daily users reported less depressed mood and more positive affect than non-users… Our results add to the growing body of literature on depression and marijuana and are generally consistent with a number of studies that have failed to confirm a relationship between the two after controlling for relevant variables…

The potential for medical conditions to contribute to spurious links between marijuana and greater depression requires further investigation.”

Apr. 2006