Marijuana can produce radically different effects depending on the person, researchers studying different areas of the brain have found.

It’s a drug that’s been legal now for close to a year, but one that researchers like Dr. Steven Laviolette of the Schulich School of Medicine and Dentistry, say needs further examination.

“From a research point of you it’s a fascinating drug because it has this diverse range of psychological effects and we are really just starting to scratch the surface as to what’s happening in the brain to control those effects.”

By using rodent models, Laviolette and his research team studied the effects THC (tetrahydrocannabinol) had on specific areas of the brain.

“We focused on the area of the brain called the nucleus accumbens, which is the frontal part of the brain, and we know there are hot spots in that area responsible for psychotic effects and addictive effects as well.”

Depending on the area of the brain, Laviolette says, some people had negative reactions to THC, which was obviously concerning.

However those who had positive reactions to THC were not in the clear.

“When we activated that area with THC, we made the rewarding effects of opioids much more salient, so it seems to modulate rewarding effects of other drugs of abuse as well.”

Negative effects of THC included psychiatric side effects that resembled a pattern similar to schizophrenia

Laviolette says with limited data on THC effects his research team will now take these findings and conduct further studies

“We are trying to move into more human image studies so that’s the goal, to sort of map out some of these pathways in the brain and also look at the underlying molecular genetic mechanism that may be responsible for this.”