Friday, November 12, 2010

Staying up to Date Part II: THC Potency and Drug Changes

Marijuana is the number one used drug in this country with the exception of alcohol, so it makes sense that for years studies have been done on it's effects on behavior, especially on driving abilities. I've attended numerous seminars and read many articles where low and high levels of THC concentration have been given to subjects so that these studies can be done. Great! We have low and high, so we're all set right?


Let's discuss: Looking at these studies the low dose of THC equates to 1.7% and the high THC equates to 3.5%. Ok, so far so good. So naturally our questions should go to how do these values compare to what is used in the real world? Well, let's see.

This September, the Journal of Forensic Sciences featured an article entitled "Potency Trends of Δ9-THC and Other Cannabinoids in Confiscated Cannabis Preparations from 1993 to 2008" which first appeared online in May of this year. This study was put together by the University of Mississippi which acts as the Potency Monitoring Program for NIDA. So, how do our studies with concentrations between 1.7% and 3.5% compare to what's out there?
Well...pretty dismally. It turns out that the average THC concentration of marijuana that has been confiscated between 1993 to 2008 has risen from 3.4% in 1993 to 8.8% in 2008. Hmm...

This is another example of why it is vital for those involved in forensics to keep up to date with the literature and the trends. An opinion given in a case using the studies for THC concentrations of 1.7% or 3.5% would be woefully inaccurate when what was smoked was closer to 9%. That is a substantial increase and one that makes a substantial difference in interpretation. It also points to why it is important that theses studies continue and continue to be funded. 

Studies are only as good as their applicability to the real-world situation.

This past week I attended the annual meeting of the Northeastern Association of Forensic Scientists which was held in conjunction with the New England Division of the International Association for Identification. It was a wonderful conference with many great people and presentations. One of which was presented by Vadim Astrakhan from the DEA in New York who made a comment about the good ole days when Ecstasy contained MDMA and it's variants. Now he is finding Ecstasy frequently that contains no MDMA at all, but does contain BZP or TFMPP. His presentation was on detecting these compounds since they co-elute, but whether your interest is in testing for the drug or discussing it's effects it's important to know what is actually out there.

The other trend in presentations was the "Spice Trade" which features plant material coated with synthetic marijuana and is sold legally. The general theme of these presentations was the concept of chasing a moving target. When there are 400 different variations of the compound where do you look? Some states are contemplating banning one or two of the compounds. How effective is that when the dealers can merely switch to one of the other 400? The appearance of spice has changed over time as well. How do you keep officers informed for what to look for now?

Keeping up to date is vital for anyone involved in forensics. Science is not static! It is ever changing and to be good at your job you have to keep up. Any state or county that under-funds their forensic section should think on that.

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