June 6 (Bloomberg) -- The U.S. Supreme Court dealt a setback to the medical marijuana movement, ruling that federal narcotics laws make it a crime to grow and use the drug even when it never crosses state lines and is used only to relieve pain or nausea.

The justices today said Congress's power over interstate commerce is broad enough to let it ban locally grown and used medical marijuana. The 6-3 ruling, issued in Washington, overturns a lower court decision that had let two California women use cannabis to treat pain, nausea and other symptoms.

California and nine other states exempt seriously ill people from laws banning cultivation and use of marijuana. Today's ruling means people in those states nonetheless will face the risk of federal prosecution if they use or distribute marijuana.

The case is Ashcroft v. Raich, 03-1454.

To contact the reporter on this story: Greg Stohr in Washington at gstohr@bloomberg.net.

Last Updated: June 6, 2005 10:20 EDT