Medical marijuana is coming to Illinois soon. The state has a long list of approved conditions for marijuana including cancer, glaucoma, HIV and multiple sclerosis.i If you have one of these conditions, you may be wondering if marijuana would be effective for you.

The best evidence is provided by double blind studies in which neither the patient nor the investigator knows what medication they are taking. Marijuana studies have two big problems:

1. A double blind study may be impossible to do since most patients can tell if they are taking marijuana or a placebo.
2. The Federal government has limited marijuana studies for years. Even though individuals find marijuana helpful for their condition, few scientific studies have been done.

For this article, 35 conditions approved by Illinois law for marijuana treatment were researched. After this, the conditions were rated by the evidence. There is good evidence marijuana can help the symptoms of chemotherapy induced vomiting and conflicting evidenceii,iii. it can alleviate severe weight loss from cancer.3 The evidence found was limited to these cancer related problems, although, marijuana may be used for any cancer in Illinois. For chronic nerve painiv and marked weight loss from AIDs there is also good evidence. Reducing muscle spasm from multiple sclerosis and pain is supported by a small number of studies,v,vi,vii but not tremor.viii

Small studies or case reports support improving symptoms of inflammatory bowel diseaseix,x, decreasing spasticity from spinal cord injury (although massage was more effective) xi and reducing side effects of hepatitis C treatment. For other conditions, either no supporting studies were found or evidence that marijuana should not be used. For example, Illinois law approves marijuana to treat glaucoma, but a 1999 Institute of Medicine Report referenced by the Illinois law advises against using marijuana for glaucoma.

Of the 35 conditions reviewed, 3 had reasonable evidence, 6 had some evidence of lower quality. No good evidence was found for the other 26 conditions in scientific medical articles. Illinois marijuana legislation clearly focuses on compassionate use for patients with difficult-to-treat illnesses.

Before you consider using medical marijuana you should try established treatments. These often work as well or better. Every treatment has risks. Marijuana can cause side effects such as confusion. Heavy use is associated with lung cancer.xii The amount of active ingredient varies between batches.
Until more scientific studies are done, there will be little or no evidence of effectiveness for many conditions. You may also have trouble finding a doctor to recommend medical marijuana. In Colorado, a small number of doctors prescribed a large percentage of the medical marijuana.

Several other aspects you should consider:

1. You can still be arrested for using medical marijuana under Federal law.
2. Medical marijuana is not cheap. An ounce in California may cost $300. This works out to $5,000-$6,000 a year with no insurance coverage. Costs in Illinois may be as high as $400 dollars an ounce. xiii
3. You can still be fired from your job after a positive drug test for marijuana or arrested for driving under the influence of marijuana. A urine drug test for marijuana may remain positive for two weeks after stopping.

In summary, medical marijuana will soon be available in Illinois. Use caution since evidence is lacking for most conditions.