BLOOMINGTON, Ind. (AP) — Two Indiana University scientists are embarking on a study of marijuana users they hope sheds light on pot’s little-understood impact on the brain — research that comes at a time when the drug has gained more acceptance in several states.
Clinical psychologist Brian O’Donnell and colleague Sharlene Newman are seeking current and former marijuana users for the study, which is one of the first of its kind. Their work is being funded by a $275,000 grant from the National Institutes of Health.
The research is taking place as marijuana is gaining more acceptance in some parts of the nation, with pot now legalized for adult use in Colorado, Washington state, Alaska and Oregon. Many other states also have medical marijuana programs, according to the National Conference of State Legislatures.
“It’s being decriminalized, but without knowledge of really its long-term effects on brain structure or function,” O’Donnell told The Courier-Journal.
He said people who choose to use marijuana need to know “what aspects of physical or mental function it might affect.”
Recreational use of marijuana remains illegal in Indiana.
Study participants will undergo a series of brain scans so the Bloomington-based research team can zero in on changes in their brains. They’ll be analyzing brain-scan images for evidence that could show how marijuana may change the brain’s structure and functions.
O’Donnell, a professor in the Department of Psychological and Brain Sciences, said animal studies and preliminary human findings suggests marijuana use can affect parts of the human brain and also the connections between them.
The IU researchers will use magnetic resonance imaging, or MRI, techniques to conduct the study on 90 people ages 18-35.
Along with current and past users of marijuana, the study, which will include people who have never used pot.
“We’re comparing the subjects in the different groups. … The group that’s never used marijuana is our baseline group,” said Newman, an associate professor and the director of IU’s Brain Imaging Facility.
The users will go through drug screening to verify that they aren’t taking other drugs so the study can focus only on the impact of marijuana on the brain, she said.
Prior to their brain scans, participants will undergo tests of perception, thinking and memory and take a questionnaire about problems they may be having, such as strange hallucinations, O’Donnell said.
In a previous study, he said the researchers found that connectivity in the brain was altered in cannabis users in a way that seemed to make the brain less efficient.
According to the National Institute on Drug Abuse, negative effects of marijuana include altered perceptions and mood, impaired coordination, difficulty with thinking and problem-solving, disrupted learning and memory.