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Source: Flickr user Free Photos.

Not many issues can fully harness the attention of the American public at the moment, but marijuana might just be one of them.

In just two decades the United States has gone from having zero states in which marijuana was legal for medical purposes and recreational use, to 23 states (as well as Washington, D.C.) passing legislation for medical marijuana and four states (plus Washington, D.C.) enacting laws to allow the drug to be sold for adult recreational use. This is truly remarkable considering that the federal government and the Drug Enforcement Administration still hold marijuana to be a Schedule 1 drug. By definition, Schedule 1 drugs have no medically defined benefit and are considered illicit.

This bifurcation between the federal government and 23 states -- and even between jurisdictions within states that have legalized marijuana across the board, such as Colorado -- have made for a dicey clash between supporters and opponents of marijuana's expansion.

Proponents and opponents square off
Supporters of marijuana see a twofold benefit for legalization. First, it represents freedom for many individuals. More importantly, though, it could give terminally ill and chronic disease patients access to a therapy that has demonstrated benefits in a number of clinical studies.

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Source: National Institute on Drug Abuse via Facebook.

States and even the federal government could also benefit from marijuana legalization through tax collection. NerdWallet estimated last year that a sweeping legalization of marijuana could net $3.1 billion in state and local tax revenue. Although such an amount would not close a large federal budget deficit, imagine what $3.1 billion could do for America's education system, or how many jobs that could create. For select states that's an intriguing proposition. Investors are also closely monitoring that figure, because the marijuana market could be enormous, and it could lead to substantial gains if the drug were legalized.

Opponents, on the other hand, will point to the many unanswered questions that surround marijuana usage. There are concerns marijuana could negatively affect a person's health and/or brain function, or that it could lead to an increased crime rate. Because so many studies for the last few decades focused on the negative effects of marijuana, these skeptics have a large amount of data to make their case.

However, a new study released last week could be a shot in the arm for the marijuana proponents camp.

Did this federal study just side with marijuana?
One of many concerns cited by legalization opponents is that marijuana can dangerously impair a driver's ability to operate a motor vehicle.

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Source: Oregon Department of Transportation via Flickr.

With that in mind, the National Institute on Drug Abuse, the Office of National Drug Control Policy, and the National Highway Traffic Safety Administration funded a test to see how well 19 adult volunteers using a driving simulator were able to stay within their lane and drive the speed limit while under the influence of alcohol, vaporized marijuana, or a placebo. Specifically, users were taken to a peak breath alcohol concentration of 0.065% and a THC concentration of 13.1 micrograms per liter. Additionally, the test was comprised of occasional marijuana users who used the drug more often than twice monthly but less than three times weekly.

As noted by the researchers, "Alcohol, but not marijuana, increased the number of times the car actually left the lane and the speed of the weaving." It could be that users understood they were "high" and they overcompensated for this feeling by driving more cautiously than normal. However, some might argue that people under the influence of alcohol tend to take more risks because they underestimate their level of impairment.

Of course, marijuana wasn't completely without side effects. Researchers noted it reduced the peripheral vision and/or awareness of those under its influence, leading to an increase in intra-lane weaving, which is consistent with what you might see with an individual who is legally impaired by alcohol. Also, the researchers noted that the combination of alcohol and marijuana, even if both were within the legal limit, increased the number of times the simulated car left the lane or weaved within the lane.

In other words, drivers under the influence of marijuana are still impaired, but they would appear to be at a lesser risk of driving erratically than people under the influence of alcohol.

Good news for proponents, but still a baby step forward
This federal study also follows recent data in and around the County of Denver that marijuana hasn't led to a societal upheaval, as once feared. As reported by online site Mic, property crime rates fell slightly in 2014 from the prior year, while traffic fatalities remain unchanged on a year-over-year basis. It's a small sample size, but the initial data would appear to suggest marijuana isn't a gateway drug to societal ruin.

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Source: White House on Flickr.

But, even with a federal study suggesting marijuana could be safer than alcohol when attempting to operate a motor vehicle, this represents nothing more than a baby step forward for legalization. The marijuana movement is still a metaphorical mile away from getting true change enacted on a federal level.

For starters, marijuana just isn't a high priority for Congress or President Barack Obama. While Obama has suggested that states like Colorado and Washington are providing a great experiment for the nation, including lawmakers, to monitor, it will be years before data on crime rates, taxes, and other areas is mature enough for federal leaders to even consider legislation that would reschedule or decriminalize marijuana.

To that same end, we also have decades' worth of studies on marijuana's adverse effects and a relatively short history highlighting its benefits. Expect this research to take time to mature before any serious comparisons can be made, and fully expect Congress to hold off on taking up the rescheduling of marijuana until all data is present. 

Even in context to the aforementioned federal study, 19 people is hardly representative of the American population. The margin for error in such a small study is likely high, meaning it represents a stepping stone for additional research, rather than the concrete answer that proponents want.

In reality, real change is probably a long ways off, meaning more waiting for marijuana supporters, and possible disappointment for investors expecting marijuana stocks to be the next great thing.

Sean Williams has no material interest in any companies mentioned in this article. You can follow him on CAPS under the screen name TMFUltraLong, track every pick he makes under the screen name TrackUltraLong, and check him out on Twitter, where he goes by the handle @TMFUltraLong.

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