The bill sponsored by Democratic Rep. Pat Noonan of Ramsay fell on a 50-49 vote.
The bill called for a label to read, “Warning: In some instances, marijuana may trigger acute psychosis or symptoms of schizophrenia and other mental illnesses.”
Noonan tells the Billings Gazette in a story published Friday that he was asked to introduce the bill by the Montana Chapter of the National Alliance on Mental Illness.
Republican Rep. David Howard of Park City opposed the bill, contending it legitimizes what he considers an illegal substance.
Montana voters approved medical marijuana in a 2004 initiative.
Information from: Billings Gazette, http://www.billingsgazette.com