That’s potentially positive news suggesting that whatever impact marijuana use might have on the size or volume of that part of the brain, it may be offset by better connectivity and structural soundness. ”It suggests that there is definitely a more complicated pattern that the brain seems to be able to compensate for any kind of loss in order to keep that network maintained,” Filbey said.

However, Filbey’s research also indicated that some of these findings could be affected by how young the person was a the time that they started using marijuana and how long marijuana use continued. People who started younger appeared to show more protective effects — stronger connectivity and integrity in their white matter. But the longer the person used the drug, those features began to erode. After about six or seven years of use, connectivity and integrity begin to erode.

“So whatever compensatory effects that there may be originally seemed to diminish with prolonged use,” she added.