Old Lyme — The Community Action for Substance Free Youth, a local prevention council, will hold a “Reefer Sanity” community forum at 7 p.m today in the Lyme-Old Lyme High School Media Center.

John Daviau, a psychologist focused on substance abuse, violence prevention and school safety initiatives, will speak at the forum.

He will address the following topics: Is marijuana really harmful? How does the state’s medical marijuana law work? What is happening with Colorado’s experiment and its impact on teens? How do we prevent another “Big Tobacco”? Following his presentation, there will be a question and answer session.

The program is free and open to the public.