Public support for legalizing marijuana has never been higher, but the latest studies show recreational use is linked with prescription drug misuse.

In the latest nationwide survey [PDF] of 1,501 people polled in mid-March about legalizing marijuana, 52% of those surveyed favored making weed legal, and 72% said that efforts to enforce anti-marijuana laws bring more cost than benefit.

The poll, conducted by the Pew Research Center, also tracked trends in public support for legalization, which has risen dramatically since 1969, when a Gallup poll found only 12% in favor.

The results revealed some interesting trends, including strong generational differences on the question, generally driven by the amount of experience each generation has with the drug.  Only 32% of the “Silent” or World War II generation born between 1928 and 1945 favored legal marijuana— and in that age group, only a tiny proportion reported ever trying it. Among Baby Boomers born between 1946 and 1964, who were the first generation to smoke pot in relatively large numbers, 50% supported legalization and around the same proportion had tried the drug.

Younger respondents from Generation X  who came of age in the 1980s and 1990s reported the highest level of youth drug use, with 60% of all high school seniors in 1980 reporting having ever tried marijuana.  Xer’s were also the generation targeted by the “Just Say No” anti-drug campaign. Only 28% of this generation favored legalization in 1994— when the media and politicians were heavily focused on fighting the drug war— while 54% now do.

Millennials who were born after 1980 were the most enthusiastic supporters of legalization, with 65% favoring ending marijuana prohibition and only 26% agreeing with the idea that smoking weed is “morally wrong.”  In contrast, 48% of the Silent Generation think marijuana use is immoral—although this is down from the 71% among that age group who felt that way in 2006.

Experience with the drug also seems to play a major role in determining where people stand on the issue. Overall, 70% of those who have tried marijuana think it should be legal, while only 35% of those who haven’t done so favor change. Politically, more  Independents and Democrats support legalization, with 60% and 59%  in favor respectively, compared to just 37% of Republicans. Interestingly, these divisions narrow dramatically when respondents were asked whether marijuana prohibition is worth the cost: 67% of Republicans, 71% of Democrats and 78% of Independents did not think spending money on enforcing marijuana laws made sense.

One factor that did not seem to influence views on legalization? Whether the survey participants lived in states that had legalized medical marijuana use; views on legalization did not vary in relation to these state laws, although the laws vary dramatically in their control over sales of the drug.

Changing perceptions on whether marijuana is a “gateway” to other drugs did seem to matter, however. In 1990, the Institute of Medicine  questioned this notion in an analysis of studies on medical marijuana use and drug abuse rates; the review did not find support for the idea that cannabis physiologically generated a need for more or other illicit drugs. Only 38% of people now agree with the idea that “for most people, the use of marijuana leads to the use of hard drugs” compared to 60% in 1977.

While marijuana use may not cause use of other drugs, there is an association between pot use and subsequent drug misuse. In the latest study, based on drug testing results compiled by Quest Diagnostics in 2011 and 2012, researchers analyzed urine samples from more than 200,000 patients that were submitted by physicians who were monitoring use of potentially addictive medications like opioid pain relievers. Because many doctors order tests only when they suspect drug misuse, the results likely do not represent those of typical pain patients or drug users.

In about 60% of the samples tested, either additional drugs that were not prescribed were found, or medications that were prescribed and should have been present were not found. In 42% of these samples that were inconsistent with the doctors’ prescriptions, the tests did not find evidence of prescribed medications.

Among those with such inconsistent test results, 26% of samples were positive for marijuana, and 45% of those samples also showed nonprescribed pain medications or sedatives in their urine. By comparison, 36% of those who did not use marijuana also tested positive for drugs, primarily sedatives and pain medications, that were not prescribed.

And medical marijuana users were no more — or less — likely to have inconsistent urine results than those who did not report medical marijuana use. This parallels previous research that showed therapeutic use of potentially addictive drugs like marijuana carried less risk for addiction than recreational use.

So what does this association mean? Studies find that marijuana users are at least twice as likely to misuse other drugs.  But the data suggests that this correlation reflects users’ desire to try new and different substances, rather than a drive to seek out the same feelings brought on by marijuana. As the Institute of Medicine report discussed:

People who enjoy the effects of marijuana are, logically, more likely to be willing to try other mood-altering drugs than are people who are not willing to try marijuana or who dislike its effects. In other words, many of the factors associated with a willingness to use marijuana are, presumably, the same as those associated with a willingness to use other illicit drugs.

Teasing apart how trends such as marijuana use and prescription drug misuse are connected will require more, and more detailed, research to better understand how each affects and influences the other, as well as other factors that could contribute to the association. That’s especially important for drug policy, given that more Americans than ever before favor legalization of marijuana.

Marijuana plants are displayed for sale at the Canna Pi medical-marijuana dispensary in Seattle on Nov. 27, 2012.

When citizens of Colorado and Washington voted in November to legalize marijuana, they created a conflict, because pot remains illegal under federal law and anyone who lights up is committing a federal crime and could theoretically still be arrested for it. After Colorado passed its referendum, Governor John Hickenlooper said the implementation of the law in his state would be a “complicated process” and warned residents not to “break out the Cheetos or Goldfish too quickly.”

While it seems unlikely that the federal government will make much of an effort to arrest pot users in Colorado or Washington — President Obama has said he has “bigger fish to fry” — the tension between federal and state laws on marijuana remains. Just last week, an appeals court rejected a suit that sought to lower the drug classification of medical marijuana under federal drug laws.

That court ruling threw the issue back to Congress and the Drug Enforcement Agency, which should start a serious reconsideration of national policy toward marijuana. The federal government should start by reclassifying medical marijuana, legalizing it outright or at least dialing down the penalties. And it should begin to have the sort of serious discussion about legalizing recreational marijuana use that is now occurring in the states.

The campaign to legalize marijuana has long been viewed as a fringe cause backed by young people and old hippies. That perception has lingered even though public-opinion polls have shown that a growing percentage of the public favors legalization — as much as 68% in one recent poll. In the past two decades, supporters of marijuana have focused on legalizing medical use, and they have had impressive success. Today, 18 states and the District of Columbia have made medical use legal, and at least seven morestates are considering it. Meanwhile, the DEA, under the federal Controlled Substances Act of 1970, still classifies marijuana as a Schedule 1 drug — a classification for drugs that have no accepted medical use. Americans for Safe Access, a pro-marijuana group, challenged this classification, but last week the U.S. Court of Appeals for the D.C. Circuit rejected the lawsuit. That ruling left in place the DEA’s blunt position that there is “no currently accepted medical use for marijuana in the United States.”

The votes in Colorado and Washington were a watershed, however, because they shifted the debate from medical use to general-use legalization. And the votes were not even close. In Colorado, the referendum passed by more than 6%. In Washington, the margin was 10%.

Afterward, Obama said the federal government has a lot of crime to prosecute and so “it does not make sense from a prioritization point of view for us to focus on recreational drug users in a state that has already said that, under state law, that is legal.” Last week, Washington Governor Jay Inslee said he had a conversation with Attorney General Eric Holder that encouraged him about his state’s ability to carry out the referendum legalizing marijuana.

It is good that the Obama Administration appears to be standing down now, but that has not always been the case. As recently as last year, the Justice Department was cracking down on medical-marijuana producers in California and other states. There is no way to know if the federal government will continue to leave marijuana policy to the states. And whatever policy the Obama Administration adopts, it could be undone when a new President takes office.

Justice Louis Brandeis once said that the states should function as “laboratories,” testing new ideas for possible adoption by the whole nation. We have seen enough over the past 16 years from the states that have legalized medical marijuana to know that the benefits are real and the alleged dangers overblown. With this data in hand, the DEA should reclassify marijuana to acknowledge its possible medical uses.

In Colorado and Washington, a bolder experiment is now under way. The rest of the nation should watch closely. It is possible that legalization will lead to higher crime rates, increased use of harder drugs and other menaces that marijuana critics warn about. But if legalization in these states has few negative effects, we will have the strongest argument yet for why marijuana should be legal nationwide.

Reported by Adam Cohen

Many unknowns if pot measure were to become law

A lame-duck session also has fueled new momentum in Springfield, according to the bill'ssponsor, Rep. Lou Lang, D-Skokie, who said last week that he was close to the 60 votes needed to pass the measure to the Senate, which has approved similar legislation before.

"It is very clear that the tenor is different," Lang said Thursday after lawmakers had adjourned for the weekend. "We're hovering around the votes we need to pass it."

But in the fragmented and emotional realm of state-permitted marijuana use, experts and advocates say that voting "yea" will likely be the easiest part. Even if the legislation is enacted, Illinois will still have to establish its own production and distribution scheme for a substance that the federal government continues to prohibit as a Schedule 1 drug, along with heroin.

"(It) is going to be a difficult and long, drawn-out process," said Paul Armentano, deputy director of the National Organization for the Reform of Marijuana Laws, which advocates amending laws to permit adults to use marijuana. "That is simply the reality of the fact that we are talking about marijuana and that we aren't talking about, I don't know, kale or something else."

States that have already legalized medical marijuana have spent years tackling a host of questions that have often produced complicated answers, such as deciding who is eligible to light up a joint or purchase and eat a marijuana-infused brownie.

Who would qualify

In most states that allow for the use of medical marijuana, patients with chronic or severe pain can qualify. California's list of conditions also includes a catchall category for any other illness for which marijuana provides relief.

In its current form, Illinois' legislation would roll out as a three-year pilot program that would be more restrictive, naming several dozen distinct medical conditions such as cancer, HIV, wasting syndrome and multiple sclerosis. The Illinois Department of Public Health could add to that list in the future.

"We have clearly defined diseases that a doctor must certify that you have or you're not getting the permit to be able to buy the product," Lang said.

While that has put some critics at ease, scientists and physicians say that medical research has shown scant evidence that marijuana is a safe and effective treatment for many of the afflictions the Illinois bill would cover.

A handful of uses in the bill — such as pain suffered by people with AIDS and cancer — are supported by some solid scientific evidence. But none meets the standards, such as large, well-designed clinical trials, required by the U.S. Food and Drug Administration in approving new drugs.

"We've got a serious issue here," said Dr. Eric A. Voth, chairman of the Institute on Global Drug Policy and a practicing internist and pain specialist. "The fundamental underpinnings of these measures bypass the FDA and I think hurt consumer protection."

Although California does not require ID cards for patients or state licensing for marijuana cooperatives, most states have moved toward an official registration and verification process to instill greater regulation, according to Armentano.

In those states, advocates point out that federal officials have largely not interfered with the medical marijuana programs.

In Colorado, for instance, patients must register with the state's Department of Public Health and Environment, which issues official ID cards. Hundreds of medical marijuana centers, infused product makers and cultivators are also regulated by the state Department of Revenue and local governments.

Registration problems, however, have cropped up in states such as Michigan, where patients and caregivers, who are allowed to provide marijuana to patients, have waited months at times for the state to issue registry identification cards.

Patients and caregivers without the IDs have faced the possibility of arrest and confiscation of their marijuana by police. Even some officially registered patients have been fired by employers after testing positive for pot.

Medical marijuana for a 7-year-old?

(TIME.com) -- Like some cancer patients in states where it's allowed, Mykayla Comstock uses cannabis as part of her treatment.

Comstock is 7-years old. Her mother, a long time advocate for medical use of the illegal drug, has been giving her a gram of oral cannabis oil every day. Despite the fact that medical marijuana is legal in Oregon, where Comstock lives, the idea of giving it to a child still gives pause to many adults who associate the drug with recreational use that breaks the law.

As reported by ABC News, Mykayla was diagnosed with acute lymphoblastic leukemia in July. Against her doctor's wishes, her mother, Erin Purchase, began giving her lime-flavored capsules filled with cannabis oil after she had a poor response to her initial chemotherapy treatment.

Her doctors suggested a bone marrow transplant, but while she was taking the medical marijuana, she went into remission in August. She continues to rely on cannabis to ease pain and nausea and her mother plans to continue giving her the drug during the additional two to three years of chemotherapy she still faces.

Purchase believes that certain components in marijuana, which show anti-cancer activity in many early studies, helped spark the remission. Mykayla's current doctor knows she takes the capsules, but doesn't discuss the marijuana as part of her medical therapy.

TIME.com: Marijuana in Colorado -- ready for business

Experts like Igor Grant of the University of California's Center for Medical Cannabis Research warn that the effects of the drug on child development are unknown. But the same is true for other medications used to fight pain and nausea that are currently given to children with cancer, as well as for powerful antipsychotic drugs that are used in long term treatment of childhood mental illnesses. Opioid drugs like morphine and Oxycontin, which are sometimes used to treat the severe pain that accompanies life-threatening cancer and other diseases, for example, can cause overdoses.

Although marijuana can be addictive, addiction rates are often lower than those to opioid drugs, and discontinuing opioids is associated with severe physical withdrawal symptoms not seen with marijuana. While opioids can cause nausea and vomiting, marijuana reduces the risk of these symptoms that frequently plague cancer patients as side effects of radiation or chemotherapy.

Advocates like Purchase argue that if opioids are acceptable to treat youngsters' cancer pain, then marijuana should be as well.

TIME.com: How cannabinoids may slow brain aging

The American Academy of Pediatrics, however, disagrees, and opposes the use of marijuana to treat young children, citing its addictive potential and the many unknowns about how it may affect developing bodies. The Institute of Medicine (IOM), a scientific group of experts consulted by Congress, analyzed the available data and since 1999 has acknowledged that certain legitimate medical uses of marijuana are worth additional study.

While the panel noted that many effective treatments already exist to relieve nausea and cancer pain, it recognized that for some patients who may not respond to these therapies, the components in marijuana may be helpful. The group's main objection to the drug was its use in smoked preparations, which is not an issue in this case.

The IOM's report highlights the need for much more research into understanding medicinal uses of marijuana -- including for which symptoms or conditions it might be most effective, and for which patients. Those concerns are magnified when it comes to treating children like Comstock, who often are not included in clinical trials because of their young age, and who may have many more years to contend with any possible side effects of the drug.

Some experts point out that not all of marijuana's components, and their effects on the body, have been studied, not to mention well understood. Without more research, both doctors and parents will continue to face the difficult decision of giving youngsters a compound and hoping it will do more good than harm.

Reported by By Maia Szalavitz, TIME.com