When Cannabis and Tobacco Combine, Your Brain’s “Bliss Molecule” Takes a Hit

"If you’re one of the millions of people who mix tobacco with cannabis — in a joint, a blunt, or a vape — your brain may be doing more than catching a buzz. It might be reprogramming its own chemistry for stress, pleasure, and addiction.
A new McGill University study found that people who use both tobacco and cannabis show striking differences in brain activity compared to those who use cannabis alone. 

*Specifically, they have higher levels of a brain enzyme that breaks down anandamide — the so-called “bliss molecule” that helps regulate mood, stress, and emotional balance.

This is the first evidence in humans of a molecular mechanism that may underlie why people who use both cannabis and tobacco experience worse outcomes.
The problem is that the two drugs act on overlapping chemical systems in the brain. 

---Both nicotine and THC influence the endocannabinoid system, a network of molecules and receptors that help control stress, reward, and motivation. 

One molecule of note in this system is anandamide, a neurotransmitter whose name comes from the Sanskrit word for “bliss.” Anandamide’s job is to keep our emotional state stable. When it’s depleted, people tend to feel more anxious or depressed.
Anandamide doesn’t stick around forever. It’s broken down by an enzyme called fatty acid amide hydrolase, or FAAH. More FAAH means less anandamide, and that imbalance has been linked to depression, anxiety, and greater vulnerability to addiction.
The results suggest that smoking tobacco on top of cannabis may intensify brain changes associated with mood instability and withdrawal.
FAAH levels in the cerebellum — a region involved not just in movement but also emotion and cognition — were strongly correlated with the number of cigarettes smoked per day. The more participants smoked, the higher their FAAH levels climbed.
That connection, said Romina Mizrahi, co-author and director of the McGill Research Center for Cannabis, was surprisingly strong: “What surprised us was how strong the effect was, and how different it was from those who only used cannabis, compared to those who used both tobacco and cannabis.”
Rabin’s team believes this might explain why people who use both substances tend to experience worse outcomes when trying to quit. “Identifying this mechanism is an important step toward finding targets for future medications to treat cannabis use disorder,” she said." 

ZME