Crystal says she truly believes that her 17-year-old son, Dominique, is addicted to marijuana. “I am so concerned about his brain. I’m sure it’s going to have long-term effects,” she says.

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Dominique, a former varsity athlete and honor roll student who dropped out of high school in his junior year, admits to smoking around seven “blunts” every day. He claims his habit helps him with anxiety and depression and denies it has had any negative impact on his academic or physical performance.

WATCH: Teen Says He Wants Dr. Phil To Change His Family’s Views On Marijuana

Dr. Phil introduces Dr. Hans Breiter, a psychiatrist at Northwestern Medicine in Chicago, the director of the Northwestern Medicine Warren Wright Adolescent Center, and co-senior author of a study that linked the casual use of marijuana and the psychoactive compound THC (tetrahydrocannabinol) it produces to major changes in the brain.

“I don’t know why people persist in thinking it’s good for the brain; why it’s good for your capabilities, your motivation, your working memory,” says Dr. Breiter, adding, “the scientific data is irrefutable at this point.”

Watch the video above to learn more about Dr. Breiter’s research and why he says, “If I were to design any compound to damage the developing brain, it would be THC.”

Check here to find out where you can see more from Wednesday’s episode.

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