Cannabis abuse and THC content are on the rise
The authors of the July 2014 Residents’ Voices article (What we ought to talk about when we’re talking about decriminalizing Cannabis, Current Psychiatry, July 2014, p. 45-46 [http://bit.ly/1uAb7iK]) highlight the mental health complications of Cannabis and mention that, when Cannabis is juxtaposed with other illicit substances, it appears innocuous.
On the contrary: Data from the 2011 Drug Abuse Warning Network highlighted the rising involvement of Cannabis in emergency department (ED) visits. The report indicated that of the 1,252,500 ED visits involving illicit drugs in 2011, the most common illicit drug involved was cocaine, which accounted for 505,224 ED visits, with Cannabis a close second at 455,668 visits—not including synthetic cannabinoids, which came in fifth, with 28,531 ED visits.1
Another useful point to buttress the concerns raised by the authors is that the potency of delta-9-tetrahydrocannabinol (THC), the primary psychoactive ingredient in Cannabis, has increased gradually over the years. The University of Mississippi Potency Monitoring Project, a National Institute on Drug Abuse–funded landmark project that studied samples of Cannabis confiscated by law enforcement in the United States between 1993 and 2008, revealed that the mean THC content increased from 3.4% in 1993, to 8.8% in 2008.2 The THC content of Cannabis is responsible for most of its psychoactive effects, so that the higher the THC content, the greater the adverse effects on mental health.
A major phytocannabinoid, cannabidiol (CBD), also present in Cannabis, appears to counteract the adverse effects of THC, particularly by means of its antipsychotic property. Compared with the rising mean THC content of Cannabis from 1993 to 2008, CBD content has remained relatively the same: a mean of 0.3% in 1993 and 0.4% in 2008.3,4
Several factors have been postulated for the trend toward a high THC–low CBD profile in recent years: cultivation methods, the preference for cultivating seedless female plants (sinsemilla) that tend to have a high THC content, and global availability of seeds over the Internet. The high THC–low CBD profile has been linked to an increased risk of Cannabis dependence and increased treatment-seeking for Cannabis-related problems.3
Maryland Treatment Centers, Inc.
Research for 'Rx: Cannabis' is needed
Regarding the essay by Drs. Gershan and Gangahar on decriminalization of Cannabis, I want to comment on issues surrounding prescription Cannabis.
It is clear that Cannabis can exacerbate psychosis, among other risks, but its potential benefits remain relatively unexplored. The authors correctly point out that, among indications for Cannabis, none are FDA-approved. Yet, off-label prescribing is pervasive and accepted in psychiatry, lack of FDA approval of indications for Cannabis is not an especially compelling argument against such prescribing.*
Lack of research and funding hampers efforts to conduct trials of the therapeutic value of Cannabis, as does its Schedule I status (ie, “no currently accepted medical use and a high potential for abuse” [language of the Controlled Substances Act]). There are reports of benefit in intractable epilepsy and posttraumatic stress disorder (PTSD) that merit further investigation; however, such research is hampered, I believe, by bureaucracy.
For example, an approved study at the University of Arizona of the use of Cannabis to treat PTSD has remained in regulatory limbo for longer than 4 years because of the immense hurdles involved in performing research on this substance—despite how pressing such research is, given the large number of veterans returning from active duty with this diagnosis and the paucity of treatment options.
Perhaps, there also is something “missing” in the debate about research into Cannabis.
Wesley Ryan, MD
PGY-5 Addiction Psychiatry Fellow
University of Washington
*Editor's Note: An earlier version of this article stated, "Yet, off-labeling prescribing of Cannabis is pervasive, and I've found, accepted in psychiatry," which does not reflect the author's opinion or intended meaning. The sentence has been corrected to read, "Yet, because off-label prescribing is pervasive and accepted in psychiatry, lack of FDA approval of indications for Cannabis is not an especially compelling argument against such prescribing."