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.