Long-term use of methamphetamine is more damaging to teen brains than to adult brains, according to a new study. The drug does its greatest damage in the area of the brain involved in a person’s ability to organize, reason and remember.

“It’s particularly unfortunate that meth appears to damage that part of the brain, which is still developing in young people and is critical for cognitive ability,” study author Dr. In Kyoon Lyoo said in a news release. “Damage to that part of the brain is especially problematic because adolescents’ ability to control risky behavior is less mature than that of adults. The findings may help explain the severe behavioral issues and relapses that are common in adolescent drug addiction.”

The researchers studied 51 teens and 54 adults, all of whom chronically abused meth, HealthDay reports. Their MRI brain scans were compared with those of 60 teens and 60 adults who did not use meth. Teen meth users had greater and more widespread brain changes, compared with adults who used the drug.

“There is a critical period of brain development for specific functions, and it appears that adolescents who abuse methamphetamine are at great risk for derailing that process,” said study co-author Dr. Perry Renshaw.

The researchers noted that teens generally use smaller amounts of meth than adults. The findings suggest it takes a much smaller amount of meth to cause greater damage in teens’ brains than in adults’ brains, they noted in Molecular Psychiatry.