The White House has responded to several of the petitions to end federal prohibition of marijuana. https://petitions.whitehouse.gov/response/what-we-have-say-about-marijuana-and-hemp-production The response cites sources on their concerns about marijuana use. From the health aspect the White House cites The National Institute of Drug Abuse  http://www.drugabuse.gov/ where the health problems associated with marijuana smoking are discussed such as memory loss, bronchitis, psychosis and the risk of cancer. Also cited are the instance of emergency room treatment in association with drug abuse at.  http://www.oas.samhsa.gov/2k10/DAWN034/EDHighlights.htm  And voluntary substance abuse treatment at. http://oas.samhsa.gov/TEDS2k7highlights/TEDSHighl2k7Tbl3.htm

The White House also denies that marijuana has any medical use, citing that no sound scientific studies support medical use of marijuana for treatment in the United States. It also states that marijuana is a dangerous drug that belongs in the schedule 1 of the Controlled Substance Act . Reality paints a much different picture where 18 states and the District of Columbia have medical marijuana programs, 2 states have legalized marijuana for recreational purposes and mountains of evidence now support marijuana as a treatment for a myriad of different ailments.

“Marijuana is listed in schedule I of the Controlled Substances Act (CSA), the most restrictive schedule. The Drug Enforcement Administration (DEA), which administers the CSA, continues to support that placement and FDA concurred because marijuana met the three criteria for placement in Schedule I under 21 U.S.C. 812(b)(1) (e.g., marijuana has a high potential for abuse, has no currently accepted medical use in treatment in the United States, and has a lack of accepted safety for use under medical supervision). Furthermore, there is currently sound evidence that smoked marijuana is harmful. A past evaluation by several Department of Health and Human Services (HHS) agencies, including the Food and Drug Administration (FDA), Substance Abuse and Mental Health Services Administration (SAMHSA) and National Institute for Drug Abuse (NIDA), concluded that no sound scientific studies supported medical use of marijuana for treatment in the United States, and no animal or human data supported the safety or efficacy of marijuana for general medical use. There are alternative FDA-approved medications in existence for treatment of many of the proposed uses of smoked marijuana.” http://www.fda.gov/NewsEvents/Newsroom/PressAnnouncements/2006/ucm108643.htm

The response also claims that marijuana potency has tripled over the last 20 years raising serious concerns about the safety of marijuana use. This argument has little meaning when we consider that most people smoke only to the point where they reach a comfortable high. It is like comparing beer to hard liquor. Would it be reasonable to assume people would drink the same amount of alcohol by volume if they were drinking 3.2% beer or 151 proof rum?                            http://home.olemiss.edu/~suman/potancy%20paper%202010.pdf

The White House also has specific claims to the efficiency of substance abuse treatments.  http://www.drugabuse.gov/publications/principles-drug-addiction-treatment/frequently-asked-questions

And the use of drug courts which require the defendant to plead guilty and pay for substance abuse treatment or counseling and submit to periodic and random drug testing also at their own expense for at least 1 year, where any failure will result in the original sentence being administered resulting in incarceration. This also drives up the number of people involved in voluntary substance abuse treatment even if they volunteered to avoid incarceration or just to save their job. http://www.drugabuse.gov/publications/principles-drug-addiction-treatment/frequently-asked-questions

It is worth noting that the only sources listed are government-funded and controlled. In the SAMSHA.gov reports about emergency room treatments it is also worth noting that the results are skewed because adult use of alcohol (age 21 and up) is deliberately left out of the results, leaving the impression that emergency room treatment associated with marijuana use is almost as prevalent as that of alcohol. It is also interesting that marijuana is listed alone but alcohol is listed alone and as used with other drugs. It would be a better comparison if all parameters were equal. It is also worth noting that just because the drug was listed as associated with an emergency room visit, it may not be the cause or the reason for the emergency room visit, just that it was noted that the patient was under the influence.