As Colorado “celebrates” its third year of marijuana legalization, reporters and marijuana enthusiasts gloat of the state’s sweeping success. “Live and let live,” they naively remark, with all the wisdom of a 1970s hippie fresh out of Woodstock. But perhaps the cannabis devotees should pause and ask themselves by what metric success ought be measured.

Most accounts of Colorado’s triumph extol the vast revenue accrued via legalization and subsequent taxation (seehere, here, and here). These heralds, however, neglect to tell you the rest of the story.

Just off 15th and Little Raven Streets in Denver, Colorado is a place called “Stoner Hill.” At Stoner Hill, Colorado’s homeless youth, who are ever-growing in number, congregate and smoke in what a Denver news site, Westword, describes as “a perpetual party, a misdemeanor micro-economy and a meeting ground for Denver’s youngest homeless and assorted travelers.” Westword reports, “The grassy hilltop is where a housing crisis meets legal cannabis, and it just happens to have a panoramic view of booming downtown Denver.”

Stoner Hill is emblematic of the growing crisis Colorado and other legalization states like Washington, Oregon, and Alaska face. Coincidentally – or perhaps not so coincidentally – both Colorado and Washington, the first two states to legalize, wereamong the top three states with the largest increases in youth homelessness from 2013 to 2014. In each state, the youth homelessness rate grew by 27 and 13.3 percent respectively in just one year.

The youth-related marijuana numbers are no less concerning and should be alarming to anyone concerned with the betterment of America’s youth.

Just this month, the U.S. Department of Health and Human Services released a surveyshowing that Colorado now ranks number one for regular marijuana use among youth. This proud achievement only came incrementally, though; Colorado once ranked a distant 14th in the country for youth usage. Once again, this jump in the rankings coincided with Colorado’s 2012 passage of Amendment 64, which legalized marijuana for recreational use.

These numbers are unsurprising, though, since Colorado’s “edibles” often intentionally resemble candy or cookies. Much like the big tobacco advertising campaigns geared toward young people, big marijuana is marketing its drug as an innocuous or appealing snack, sure to garner youth attention. Stanford Law Professors Rob MacCoun and Michelle Mello have dubbed it an “attractive nuisance.”

The distrusting naysayer would retort that Colorado is just one state and should not be a bellwether for the nation. Colorado, however, is not alone in its marijuana accolades. When you consider “average past month use of marijuana by those 12 to 17 years old” – the main metric for youth usage – the cynic has a lot of explaining to do. Average youth use among teens in recreational/medical marijuana states rests at 10.5 percent compared to 8.9 percent in states where it is only legal for medicinal purposes and 6.1 percent in states were the drug is banned altogether. In other words, there is a direct correlation between availability of marijuana and teen usage.

Teenage use numbers alone do not fully capture the impending crisis Colorado and other states face. According to Arapahoe House Treatment network in Colorado, teenage admissions for marijuana addiction in Colorado increased by 66 percent between 2011 and 2014, again correlating with the 2012 passage of Amendment 64. This phenomenon is entirely predictable by science.

Dr. Christian Thurstone of the University of Colorado explains the epidemic this way:

I’m interested in this subject because 95 percent of the teenagers treated for substance abuse and addiction in my adolescent substance-abuse treatment clinic at Denver Health are there because of their marijuana use, and because nationwide, 67 percent of teens are referred to substance treatment because of their marijuana use. Marijuana is the No. 1 reason why adolescents seek substance-abuse treatment in the United States.

Citing a study by Wayne Hall and Louisa Degenhardt, Dr. Thurstone points out that two-thirds of new marijuana users annually are under the age of 18, and one in six of those new users will go on to use regularly or become dependent on the substance. For Colorado, this is a troubling finding.

Marijuana usage is not only detrimental for its addictive characteristics but also for its long-term effects on the adolescent brain. Marijuana has “acute (meaning up to six hours), subacute (6 hours to 20 days) and long-term (more than 20 days) effects.” Where the subacute effects of alcohol can be the annoyance of a brief hangover, marijuana can have substantial lingering effects, especially for young people.

Charles Stimson of the Heritage Foundation reports that, while alcohol is broken down quickly, THC – the main active chemical in marijuana – is stored in the body, where it can remain for days or weeks and impair cognitive ability for enduring periods of time. Consequently, using the drug is associated with “lower test scores and lower educational attainment.”

The long-term effects are most worrisome. A comprehensive New Zealand study of 1,000 individuals over many years found that participants who used cannabis heavily in their teens had an astonishing average loss of eight IQ points. Accordingly, Dr. Michelle Cretella, President of the American College of Pediatricians, notes that “[m]arijuana’s impact on the teen brain leads to an increased risk of motor vehicle accidents, sexual victimization, academic failure, permanent loss of IQ, psychopathology, addiction, and psychosocial and occupational impairment.”

Sadly, youth usage is not the only devastating impact legalization has had. In Colorado, “pot-positive traffic fatalities” have increased 100 percent, emergency room visitsrelated to marijuana have increased 57 percent, and infant exposure has increased 268 percent since legalization.

But the adverse impact on America’s youth should be enough by itself to trigger scrutiny and reform. Former Drug Czar William Bennett remarked: “We know we have a problem, and we have not managed to keep those things from kids. Colorado was supposed to eliminate the marijuana black market, but it did not.”

While supporters applaud America’s new cash cow – marijuana – perhaps we should ask ourselves whether this newfound flow of revenue should be hoarded at the expense of America’s youth – the marijuana martyrs.