Medical marijuana is legal in more than 15 states in the U.S. However, it remains controversial as state laws continue to run into conflict with federal regulations.

In California, for instance, federal prosecutors had launched an aggressive crackdown on medical marijuana dispensaries that were allegedly just trying to rake in huge profits under the guise of complying with state law. Last year, 71 pot stores in Los Angeles County were targeted by federal authorities as part of the ongoing crackdown.

Benefits of Marijuana
The latest available statistics show there are approximately 1 to 1.5 million Americans who are legitimate medical marijuana patients. Albeit limited, previous studies have shown how cannabis can be of help to patients with certain debilitating conditions, such as cancer and AIDS/HIV. According to the National Cancer Institute, the potential benefits of medical marijuana for cancer patients include antiemetic effects, appetite stimulation, pain relief, and improved sleep.

Dr. Tod H. Mikuriya, a California psychiatrist who helped make the use of marijuana for medicinal purposes legal in the state, began studying marijuana's medicinal benefits in the 1960s. He held a list of over 200 ailments whose symptoms can be relieved by cannabis use. These symptoms include stuttering, insomnia, premenstrual syndrome, writer's cramp, poor appetite and some side effects of cancer treatment like nausea and vomiting, according to a 2007 New York Times report. Before he died from complications of cancer in 2007, he reportedly wrote marijuana prescriptions for nearly 9,000 patients.

Some marijuana proponents claim that the drug has anti-bacterial properties which inhibits tumor growth and helps in enlarging the airways, thereby easing the severity of asthma attacks. Others claim that marijuana provides therapeutic relief for patients with PTSD and multiple sclerosis, as well as to help control seizures and muscle spasms in people suffering from epilepsy and spinal cord injuries.

But despite all those claims, marijuana advocates are finding it hard to convince the U.S. Drug Enforcement Administration (DEA) to reclassify marijuana from its current status. The DEA strongly stands firm on its position on marijuana, categorizing the drug as a Schedule I substance -- which declares it has " high potential for abuse, has no accepted medicinal value in treatment in the United States."

Risks of Marijuana
One of the significant concerns about medical marijuana is the recommended dosage for patients. When doctors prescribe their patients with painkillers or other drugs, there are specific instructions on when to take the medicine, how much should be taken and for how long. Unfortunately, such detailed instructions are not available for patients prescribed with medical marijuana. That's because there are several factors that influence the effects of marijuana to patients, such as the strain of cannabis the patient is using; how often the patient medicates; and how the marijuana was grown, harvested, and stored -- to name a few.

When it comes to death rates associated with marijuana use, available data would say it's safer than alcohol. A 2001 mortality data report by the Substance Abuse and Mental Health Services Administration (SAMHSA) indicated that while there had been several cases of death involving marijuana, the figure is at a much lower frequency than alcohol, cocaine, or heroin/morphine. But according to the FDA AERS report, the number of deaths caused by marijuana from 1997 to 2005 was 0. Similarly, a 2009 data from the DrugWarFacts.org indicated a 0 death toll from cannabis use.

The negative effects of marijuana have also often been associated with physical, social, behavioral, academics, and mental health of the users. Several studies suggested that marijuana use could trigger attacks of mental illnesses, such as psychosis and schizophrenia. There were also studies linking marijuana use to impaired perception, judgment, thinking, memory and learning. A recent study from Duke University found that people who frequently use marijuana are at risk of slowing down their IQ.