New Study Highlights The Good, The Bad And The Unknown About Marijuana

It can almost certainly ease chronic pain and might help some people sleep, but its also likely to raise the risk of getting schizophrenia and might trigger heart attacks.

Those are among the conclusions about marijuana reached by a federal advisory panel in a report released Thursday.

The experts also called for a national effort to learn more about marijuana and its chemical cousins, including similarly acting compounds called cannabinoids.

The current lack of scientific information "poses a public health risk," said the report released by the National Academies of Sciences, Engineering and Medicine. Patients, health care professionals and policy makers need more evidence to make sound decisions, it said.

Several factors have limited research. While the federal government has approved some medicines containing ingredients found in marijuana, it still classifies marijuana as illegal and imposes restrictions on research. So scientists have to jump through bureaucratic hoops that some find daunting, the report said.

Federal prohibition impedes research

A federal focus on paying for studies of potential harms has also impeded research into possible health benefits, the report said. The range of marijuana products available for study has also been restricted, although the government is expanding the number of approved suppliers.

Twenty-eight states and the District of Columbia have legalized marijuana for a variety of medical uses, and eight of those states plus the district have also legalized it for recreational use.

The report lists nearly 100 conclusions about marijuana and its similarly acting chemical cousins, drawing on studies published since 1999.

It found strong evidence, for example, that marijuana can treat chronic pain in adults and that similar compounds ease nausea from chemotherapy, with varying degrees of evidence for treating muscle stiffness and spasms in multiple sclerosis.

Limited evidence says marijuana or the other compounds can boost appetite in people with HIV or AIDS, and ease symptoms of posttraumatic stress disorder, the report concluded. But it said theres not enough research to say whether theyre effective for treating cancers, irritable bowel syndrome, epilepsy, or certain symptoms of Parkinsons disease, or helping people beat addictions.

There may be more evidence soon: a study in Colorado is investigating the use of marijuana to treat PTSD.

Turning to potential harms, the committee concluded:

• Strong evidence links marijuana use to the risk of developing schizophrenia and other causes of psychosis, with the highest risk among the most frequent users.
• Some evidence suggests a small increased risk for developing depressive disorders, but theres no evidence either way on whether it affects the course or symptoms of such disorders, or the risk of developing post-traumatic stress disorder.
• Theres strong evidence that ...