Marijuana appears set for a critical year. We've already witnessed nearly two-dozen states approve marijuana for medicinal use since 1996 (the year in which California became the first state to legalize the use of cannabis for certain ailments), and residents in four states have voted to legalize recreational marijuana since 2012. Now, come November, we could see around a dozen more state-level marijuana initiatives and referendums on ballots.

Grassroots campaigns in California and Florida are working tirelessly to get marijuana initiatives on the ballot and in front of voters. In Ohio, organizers are trying to regroup after a disappointing defeat this past November, which seems mostly to have been a negative reaction to the oligopolistic grow farms that would have been created by the language of the proposal rather than opposition to marijuana itself. In Vermont, lawmakers are considering passing a recreational marijuana law in the state's legislature rather than even putting it in front of voters. Long story short, marijuana could see a very rapid expansion following the November elections.

On the flipside, we've witnessed lawmakers on Capitol Hill doing a whole lot of nothing when it comes to marijuana reforms. Congressional inaction, combined with President Obama suggesting that marijuana isn't on his agenda in his final year in the Oval Office, seems to have doomed the marijuana industry to continued disadvantages.

Marijuana's clearest path to approval

For supporters of marijuana, the path to approval appears cloudy at best. However, a new study released just weeks ago suggests that marijuana's best chance at federal approval could be solely for medicinal use. In other words, forget the idea of recreational legalization (for now) and focus solely on legalizing marijuana for specific medical ailments.

The study in question comes from researchers at the Hebrew University of Israel who evaluated the responses of patients to THC-dominant cannabis taken daily over the course of six months. The 176-patient study involved patients with chronic pain conditions who had been previously unresponsive to traditional pain medications.

The findings? Two-thirds of patients in the study experienced an improvement in their pain symptom scores after using cannabis -- improving from an average of 83.3 to an average of 75 -- and a majority of those treated saw robust improvements in their quality of life. More interestingly, opioid consumption dropped 44% during the study, and quite a few patients completely ditched opioid use altogether.

Here's the official conclusion from the seven study authors:

The treatment of chronic pain with medicinal cannabis in this open-label, prospective cohort resulted in improved pain and functional outcomes, and significant reduction in opioid use. The results suggest long-term benefit of cannabis treatment in this group of patients, but the study's non-controlled nature should be considered when extrapolating the results.

As we see with most initial or small-pool studies, the findings won't be considered concrete until a larger or more controlled study is undertaken. However, the correlation between pain reduction and marijuana here is fairly consistent with other studies that have emerged over the last couple of years.

Saving lives and money

What makes this study even more intriguing is that a 2014 study published in the Journal of the American Medical Association Internal Medicine by a team of researchers at the University of Pennsylvania showed that states with medical cannabis laws in place had a roughly 25% lower mean annual opioid overdose mortality rate than states that did not have cannabis laws on the books.

This trend was also noted to increase over time, with opioid-related overdose deaths declining by 20% one year following the implementation of a medical cannabis law, 25% after two years, and 33% after years five and six. This is noteworthy since the Centers for Disease Control and Prevention points out that prescription painkiller overdoses have jumped by more than 400% for women between 1999 and 2010, and 237% for men over the same time span.

This would imply two key points. First, that medical marijuana could potentially reduce the number of overdose-related chronic pain deaths. In 2014, not a single person who overdosed on marijuana died from it. By comparison, some 18,900 people die annually from overdoses tied to opioid-related medications. Reducing the use of opioids in favor of THC-based medicines could, in theory, mean fewer overdose-related deaths.

Additionally, the CDC pinpointed the direct and indirect costs (i.e., lost productivity) of opioid overdoses at $55.7 billion in 2007 -- and this figure has presumably risen since then. Although marijuana overdoses cost the healthcare system as well, the total cost of marijuana overdoses is unlikely to be even close to the same caliber as opioid-induced overdose costs.

Thus, using marijuana as an alternative to opioids, assuming a similar pain-reducing effect is observed, could be a life- and money-saving move.

Of course, the allure of marijuana as a medicine is that it's demonstrated numerous benefits beyond just pain reduction. In clinical trials we've witnessed improved glycemic balance for type 2 diabetes, heightened sensitivity to radiation for certain types of brain cancer, and a marked reduction in seizures for certain childhood-onset epilepsy patients.

It would appear that angling for the approval of medical marijuana at the federal level, where public support for legalization stood at 84% according to a CBS News poll in 2014, could be the smart way to go.

The waiting game continues

But for marijuana supporters and investors, the waiting game is expected to continue. The 2016 presidential election could possibly bring change, with a small handful of candidates demonstrating favorability toward marijuana. However, the vast majority, if elected, would probably leave the current status quo firmly in place, or perhaps even take a step back from where we are now.

Inaction at the federal level continues to make investing in the marijuana industry a complete crapshoot. Those aforementioned inherent disadvantages include unfair taxation, since marijuana businesses are unable to take normal business deductions, such as rent, as well as limited or no access to basic banking services. If businesses can't even open checking accounts, their prospects of expansion remain very limited outside of turning to venture capitalists. This doesn't paint a particularly good picture for the marijuana industry, at least as it relates to investors.

Yet if federal inaction is going to be broken, it's likely to come in the form of a medical marijuana approval, as opposed to a push to legalize the drug for recreational use. We could still be years away from seeing something like this happen (if it ever happens) since lawmakers are still gathering critical safety information on marijuana, but it's something to keep your eyes on as marijuana marches forward at the state level.