A new study shows that marijuana extracts may reduce spasticity symptomsin people with multiple sclerosis.

Five of the six published studies analyzed by Shaheen Lakhan, PhD, and Marie Rowland, PhD, of the Global Neuroscience Initiative Foundation in Los Angeles, reported a reduction in spasticity and an improvement in mobility in MS patients treated with marijuana extracts.

The extracts were administered orally according to Lakhan. The use of cannabis extracts delta9-tetrahydrocannabinol, or THC, and cannabidiol, or CBD, in people with MS were included in the reviewed studies.

"We found evidence that combined THC and CBD extracts may provide therapeutic benefit for MS spasticity symptoms," Lakhan says in a news release.

A paper that was published in the journal BMC Neurology, the researchers write that recently introduced therapies of combined THC and CBD have the potential to release symptoms and that past reviews have also suggested that cannabinoid therapy is beneficial for people with MS.

The results of the reviewed studies were published between 2002 and 2007 and they included data from almost 500 people with MS. Out of the total six studies, five reported significant improvements in spasticity. One of the studies reported no improvement in spasticity.