Researchers discovered that combining tobacco with cannabis affected the brain differently than using cannabis alone.

Brain scans showed dual-users had higher levels of an enzyme that breaks down anandamide — a natural compound linked to mood, calmness and emotional balance. The more active this enzyme became, the faster the brain removed its own “feel-good” signals.

The findings suggested that mixing tobacco didn’t just change the experience in the moment — it could alter how the brain processed stress and reward over time.