One of the biggest brain imaging studies yet found the five biggest drivers of brain aging -- and smoking marijuana is one of them.
The study evaluated 62,454 brain scans of more than 30,000 people from 9 months old to 105 years old and looked at "regional cerebral blood flow in the brain that is reduced in various disorders."
The Journal of Alzheimer's Disease published the study done by scientists from Amen Clinics, Google, John's Hopkins University, University of California, Los Angeles and the University of California, San Francisco.
Researchers found that schizophrenia, marijuana abuse, bipolar disorder, ADHD and alcohol abuse are among the top things that can age your brain.
"The cannabis abuse result was especially important, as our culture is starting to view marijuana as a harmless substance," Dr. Daniel G. Amen, psychiatrist and lead author of the study said. "This study should give us pause about it."
Cannabis abuse was found to age the brain by 2.8 years. Schizophrenia is said to age the brain by four years, bipolar disorder by 1.6 years, ADHD by 1.4 years, and alcohol abuse by 0.6 years.
Researchers studied 128 brain regions to determine the chronological age of the patient. Accelerated aging was found when the brain scan age didn't match the patient's chronological age.
The study found that these five behaviors and disorders predicted accelerated aging.
The Center for Brain Health at the University of Texas at Dallas cited a similar study comparing marijuana use to brain aging and development.
That study described how those who began using marijuana at age 16 or younger had different forms of arrested brain development. Those who started using pot after age 16 showed the opposite effect -- their brains aged faster.
Dr. Francesca Filbey with the Center for Brain Health said that studies show "the timing of cannabis use can result in very disparate patterns of effects."
Filbey said the age of use impacts both brain development and maturation.
