Category Archives: Drugged Driving

Does Marijuana Affect Driving Ability?

It is against the law to drive while under the influence of marijuana. It has always been assumed that cannabis, like alcohol, impairs the perception, coordination, reflexes and judgment necessary for the safe operation of a motor vehicle. And, of course, there have been governmental studies addressing the question: Does marijuana impair driving?

Interestingly, however, the findings do not necessarily support popular opinion….

On the one hand, the California Department of Justice has found that marijuana undoubtedly impairs psychomotor abilities that are functionally related to driving and that driving skills may be impaired, particularly at high-dose levels or among inexperienced users. "Marijuana and Alcohol: A Driver Performance Study", California Office of Traffic Safety Project No. 087902 (Sept. 1986).

Contradicting these conclusions, however, are two federal studies. The U.S. Department of Transportation conducted research with a fully interactive simulator on the effects of alcohol and marijuana, alone and in combination, on driver-controlled behavior and performance. Although alcohol was found consistently and significantly to cause impairment, marijuana had only an occasional effect. Also, there was little evidence of interaction between alcohol and marijuana. Accidents and speeding tickets reliably increased with alcohol, but no marijuana or combined alcohol-marijuana effects were noted. "The Effects of Alcohol on Driver-Controlled Behavior in a Driving Simulator, Phase I", DOT-HS-806-414.

A more recent report entitled "Marijuana and Actual Performance", DOT-HS-808-078, noted that "THC is not a profoundly impairing drug….It apparently affects controlled information processing in a variety of laboratory tests, but not to the extent which is beyond the individual’s ability to control when he is motivated and permitted to do so in driving". The study concluded that:


An important practical objective of this study was to determine whether degrees of driving impairment can be actually predicted from either measured concentration of THC in plasma or performance measured in potential roadside "sobriety" tests of tracking ability or hand and posture stability. The results, like many reported before, indicated that none of these measures accurately predicts changes in actual performance under the influence of THC…


The researchers found that it "appears not possible to conclude anything about a driver’s impairment on the basis of his/her plasma concentrations of THC and THC-COOH determined in a single sample".

Note: "THC" stands for Delta-9-tetrahydrocannabinol, which is the intoxicating ingredient in marijuana. THC is fairly quickly converted by the body into inert metabolites, which can stay in the body for hours or even days. It is these metabolites that police blood tests in DUI arrests detect and measure. In other words, (1) marijuana may not impair driving ability at all, and (2) the blood "evidence" only measures an inactive substance which may have been there for days. thc & marijuana detox
 

Driving + Trace of Marijuana = DUI

In the This-Is-Getting-Ridiculous department:


Blood Test for Marijuana Unreliable for DUI Penalty

Lexington, KY.  Jan. 17  - Once again, a bill that seeks to punish prior use of a controlled substance with an automatic DUI conviction is before the Kentucky legislature.

Like its predecessors, Senate Bill5 cleverly attempts to bootstrap an ill-advised rule regarding all drugs onto a rule created for the purpose of measuring alcohol impairment. Under SB5, a driver who tests positive for traces of marijuana can be convicted of "driving under the influence" even if that driver is unimpaired at the time of arrest.

While such laws do little to actually make roadways safer, they do send many innocent people to jail and saddle them with criminal records for the rest of their lives. Current Kentucky DUI law requires prosecutors to prove that a suspect was impaired while driving. SB5 seeks to circumvent current evidentiary standards by removing this requirement. If lawmakers want to clog court dockets, cost taxpayers more money and make it tougher for Kentuckians to find and retain employment, then this is the bill to support…

Moreover, the test referred to in SB5 is not a test for marijuana impairment, but merely a test for marijuana’s presence, which is not what DUI laws are supposed to punish.

The effect and perhaps even the aim of legislation like SB5 is to punish prior drug use — predominantly marijuana use — by convicting drivers of DUI without scientifically reliable evidence that they were operating a vehicle while under the influence of anything.

"Zero-tolerance" laws are more than unjust; they are scientifically unsound, which is exactly why not one single state applies such a rule to alcohol. Furthermore, these laws are even less suited for marijuana, the traces of which are detectable by drug tests long after its intoxicating effects have worn off…

A driver with high levels of THC (the active psychotropic ingredient in marijuana) in the blood may not be impaired in any manner if time has passed since the substance was last used. The inability to accurately measure marijuana impairment is why both the National Highway Traffic Safety Administration and the National Institute on Drug Abuse have stated that marijuana impairment testing via blood sampling is unreliable.

Driving under the influence of any substance is dangerous and should not be tolerated, but sending innocent people to jail for DUI using methods incapable of accurately measuring impairment is not the answer. 
  

(Thanks to Nathan Miller) 

Prescription Drugs Cause Craving for Alcohol

Interesting review concluding that certain common prescription drugs are causing a craving for alcohol and, possibly, alcoholism: 


Alcohol Cravings Induced via Increased Serotonin

There is an alarming connection between alcoholism and the various prescription drugs that increase serotonin. The most popular of those drugs are: PROZAC, ZOLOFT, PAXIL, LUVOX, SERZONE, EFFEXOR, ANAFRANIL, and the new diet pills, FEN-PHEN and REDUX. For seven years numerous reports have been made by reformed alcoholics (some for 15 years and longer) who are being "driven" to alcohol again after being prescribed one of these drugs. And many other patients who had no previous history of alcoholism have continued to report an "overwhelming compulsion" to drink while using these drugs…

For some time we did not have specific medical documentation to help us understand why this was happening. Could it be that Prozac, Zoloft, Paxil, etc., being mood altering substances, were removing the inhibitions that individuals had placed upon themselves to stop their additions? But beyond this mood altering effect of Prozac, etc., there seemed to be a physiological cause for this alcoholic obsession as well. There were reports of people who rarely drank before Prozac, etc., consuming excessive amounts of alcohol after starting usage of these various drugs.

In November of 1994 Yale published a study that gave us one answer to the alcohol cravings associated with these drugs. The study demonstrated that an increase in brain levels of either of two neurotransmitters (brain hormones), serotonin or noradrenalin, produces: #1 a craving for alcohol, #2 anger, #3 anxiety. They found this to be especially true for those who have a history of alcoholism…


The Yale study mentioned is Specificity of Ethanol-like Effects Elicited in Serotonergic and Noradrenergic Mechanisms," ARCHIVES OF GENERAL PSYCHIATRY, Vol. 51, Issue 11, pgs 898-911.


(Thanks to William C. Head.)