First-of-Its-Kind Study Finds Marijuana in Blood One Month After Abstinence
The legalization of marijuana in states like Colorado requires additional regulation to make the legalization safe for all residents. For instance, there are many adverse effects associated with the use of cannabis, such as an increased risk of psychotic episodes. In addition, cannabis use may impact other areas of physical and mental health.
The legalization of marijuana may also significantly impact legislation related to its use in connection with operating a vehicle. The use of cannabis is connected to impaired driving and the cause of motor vehicle accidents, second only to alcohol for its role in dangerous driving.
According to the National Roadside Survey, there were more drivers tested positive for drugs than for alcohol in 2007, and in 2009 more than 10 percent of young adults admitted to driving while under the influence of illegal drugs.
In a study recently published online in Clinical Chemistry, researchers provided evidence that even when a daily smoker of cannabis ceases using the drug, it can be detected in the blood up to one month later.
The researchers recruited 30 men who were chronic daily marijuana smokers. They were required to remain at a secure research unit for up to 33 consecutive days, with blood collected on a daily basis. Of the 30 participants, 27 tested positive for THC when they arrived at the research unit. The THC levels gradually declined over the residence period, with only one of 11 participants negative at 26 days. At 30 days, two of five participants were still testing positive for THC.
The findings show, for the first time, that cannabis may be detected in the blood for up to one month after a sustained abstinence period. The findings are consistent with previous research that shows neurocognitive impairment that extends past the current use of marijuana.
The findings suggest that there may be a benefit achieved in the pursuing of “per se” legislation that could reduce the number of accidents and deaths associated with the use of marijuana. This same type of legislation has been successful in reducing alcohol-related deaths, as well as improving the process of prosecution of drunk drivers.
Author of the paper, Dr. Marylin Huestis of the National Institutes of Health, explains that the research is the first of the its kind. Previously, the research has not been possible due to the high cost of examining the sustained abstinence of a daily marijuana user. It is difficult to examine the effects of chronic cannabis smoking. She says that the findings add important insight about the toxicity in the blood when cannabis is used on a daily basis.