Think (Clearly) Before Voting to Legalize THC

I encourage people think before they vote for the legalization of marijuana, Proposition 19 in the November 4 election. This is a different view, coming from a physician specialized in psychiatry as well as addiction, and a resident of our beloved state of California.

I am not going to speak here to whether marijuana is addictive or not, nor am I going to discuss the medical implications of its use. I am going to address the behavioral implications of marijuana use with regard to driving safety, job performance, and financial problems. I am using alcohol as a comparison for legalized marijuana.

Tetrahydrocannabinol (THC), the active ingredient in marijuana, has a very long half-life. It stays in your system for 25 to 30 hours, five times longer than it takes alcohol to get it out of your system after last use, and the effects can last even longer for chronic users. Alcohol has a comparatively short half-life and can be eliminated faster. I agree that alcohol might have more medical complications, but it gets out of your body faster. For example: If a person were to consume enough alcohol to become inebriated on Friday and Saturday, their system should be clear of alcohol on Monday, unlike THC. We are still talking about recreational use, and not chronic use.

So what is wrong with having THC in my brain?

THC can cause psychomotor impairment including but not limited to the following:

Object distance and outline are often distorted.

The ability to make rapid critical judgments is impaired (as demonstrated in a study by Isabel Gorodostky, et al, published in 1967).

Reaction time, information processing, and time perception are all slowed, while perceptual motor performance is impaired. (Shown by Chait and Piere, 1992.)

I am sure you can see how all of the above are going to affect driving. Would you feel safe with more drivers like that on the road?!

Besides psychomotor impairment, marijuana bestows cognitive impairment. THC interferes with short-term memory—and the longer the THC use the more pronounced the cognitive impairment. A 1988 study (by Page, Fletcher, et al) showed that THC alters memory, attention, and their integration as needed to perform complex tasks. Also, marijuana has a deleterious effect on curiosity, which is very important for problem-solving and motivation. THC use is associated with higher risk of quitting high school, and a higher rate of job turnover, as well as poorer job performance. I hope it is clear from the foregoing the ways in which marijuana could negatively affect work performance in our state, at a time when we need the sharpest brains possible.

Unfortunately, a lot of people think that marijuana is harmless and does not affect your body organs like alcohol affects your liver, which might be true if you do not consider the brain to be an organ. I have patients who thought the drug was harmless, only to realize that their grades in school went way up after they stopped smoking marijuana; they reported more mental clarity without it.

I personally do not want the person who does my taxes, for example, to be under the influence of marijuana. Any mistake he makes due to cognitive impairment or simple lack of concentration may drain my time and energy, not to mention my finances. Do you want the surgeon who is going to operate on you to be under the influence of THC, experiencing lack of concentration and memory problems? For that matter, do you want the attorney defending you in court on drug-related charges to be under the influence?!

Not that we even have an accurate way to test whether somebody is under the influence of THC. We do not yet have a test to distinguish recent use from use more remote in time, nor do we for have a quantitative test. So a driver, for example, may very well be impaired by marijuana, but the lack of testing makes it difficult to determine the cause. By contrast, it is relatively simple to enforce our laws against driving when your alcohol level is above 0.08.

In addition, THC intoxication does not show as a linear curve, meaning that the blood level does not correlate to the impairment. You can argue also that we do not have impairment levels for opioids or Xanax or Valium, but at least these medications are controlled by physicians who, with the help of pharmacists, monitor the quantities prescribed. The drug dosage is not left uncontrolled, as THC intake would be if marijuana were legalized.

Speaking of which, marijuana ranks ahead of alcohol in terms of drug-related admissions to emergency rooms—it is the second most commonly detected drug, according to Principles of Addiction Medicine (Third Edition, page 250).

I hope you take the time to consider the impact legalization will have on you and me and our great State of California before going to vote on prop 19.

Sherif El-Asyouty is a psychiatrist and co-medical director of Recovery Road Medical Center in Santa Barbara.