It’s a question that has long baffled marijuana users. Why is it that cannabis makes some people happy and relaxed and provides them an escape, while it makes other people anxious?

Does Cannabis Make You Paranoid?

The answer, a new study has found, is “it depends.” And what the study found it depends upon is how THC, the chemical in marijuana that causes the high feeling, interacts with receptors in your brain.

Apparently, genetics could be the reason some people can’t stop laughing when they use marijuana and feel like they are in the best mood ever, while others keep biting their fingernails. In the latter case, cannabis does make you paranoid.

The Study’s Main Findings

The new study comes from the University of Western Ontario in Canada. Researchers there used rats to test the effects of THC. What they found is somewhat technical, but it goes like this:

• The nucleus accumbens is the frontal region of the brain associated with reward behavior and the neurotransmitters dopamine and serotonin.
• Both dopamine and serotonin result in good feelings
• This is the part of the brain THC apparently impacts the most
• THC attaches primarily to receptors in the nucleus accumbens front area. This leads not only to feelings of euphoria but also to more reward-related activity patterns in the neurons. That’s all very “feel good” stuff.
• However, it’s a different story if THC attaches to the anterior of the nucleus accumbens, which is a region associated with “aversion processing”
• When that happens, it can lead to adverse cognitive and emotional symptoms.

This apparently is the reason why sometimes it’s fun to get high, and other times it is not. But it also leads to another question: why does it work differently with different people?

Genetic Variation and Marijuana

In a statement about the research, Christopher Norris said the study’s findings are important because “they suggest why some people have a very positive experience with marijuana when others have a very negative experience.”

Genetic variation in the rat subjects is what led to the different outcomes, Norris said. That variation leads to people having different sensitivities in this area of the brain, with receptors attaching to THC in different areas.

In short, there might not be anything you can do about it if certain types of marijuana give you a negative feeling. In that sense, the answer to “does cannabis make you paranoid?” is “yes.” But it might impact you differently, depending on the strain of cannabis.

Steven R. Laviolette, another researcher on the study, told Yahoo that the next logical step is human testing. However, he warned that research into this area is just now starting to unravel the mysteries around “some of the more intricate details of how cannabis is affecting the brain.”

“Monitor your use and if you’re experiencing negative side effects, talk to your physician,” he said.