IU Receives Grant For Adolescent Cannabis Use Study

While adolescent cannabis use is not a new phenomenon, it is an issue that has some people concerned as legalization spreads across the country and around the world.

To get a better idea of how cannabis use may affect developing brains, researchers at Indiana University (IU) have launched a study involving individuals between 12 and 14 years old.

Researchers say using cannabis during adolescence may impair working memory and increase chances of developing psychosis later in life.

The National Institute on Drug Abuse (NIDA) recently awarded more than $2 million to the IU Gill Center for Biomolecular Science to research the impact of cannabis use on adolescents.

IU says the goal of the study, which uses mice, is to develop therapies to treat adverse reactions in humans.

Health Concerns for Adolescents

IU College of Arts and Sciences’ Department of Psychological and Brain Sciences Professor Hui-Chen Lu believes adolescent cannabis use is a significant health concern.

“Today’s cannabis strains are being bred for increased THC content,” says Lu. “It’s very different and much riskier than the more traditional strains used in the past. There’s an urgent need to understand the effects of these new strains.”

Lu points out that dispensaries in legal states sell edible products that young people find attractive.

Psychological and Brain Sciences Department Professor Ken Mackie says that heavy users of high-THC cannabis between 12 and 14 years old are two-to-five-times more likely to develop schizophrenia or another psychotic disorder.

“One of the functions of the prefrontal cortex is working memory, as well as processes like planning and impulse control,” says Mackie. “That part of the brain is still developing in adolescence, and developing brain structures are particularly vulnerable to environmental impacts, such as drug use or stress.”

Lu says sex-dependent changes need identified.

“For example, working memory originates in the brain’s prefrontal cortex, which develops a lot later, especially in boys,” says Lu. “That could be why boys are more susceptible to THC exposure and more likely to suffer negative effects.”

According to Lu, the human brain is not precisely wired from the beginning and requires input from environment, experience, and interactions with others.

Lu says a properly configured prefrontal cortex is crucial for goal-directed behavior and social interaction.

“If cannabis disrupts prefrontal cortex development during this critical period, the impact can be huge and long-lasting,” says Lu. “To help these individuals, we need to figure out which therapies will work based on our understanding of what happens in the brains of young adolescents using cannabis.”

Researching Cannabis

For Lu’s and Mackie’s research, IU says the pair will use their new method involving mice to better comprehend how cannabis affects adolescents.

IU says Lu and Mackie chose mice of both sexes with diverse genetic backgrounds to simulate human diversity.

Because previous studies did not use male and female mice, they could not determine sex-dependent differences in THC effects.

IU says Lu and Mackie will study underlying molecular changes that explain behavior changes like working memory deficits.

Additionally, IU says the researchers will study cannabidiol (CBD) because it exists in THC-rich cannabis that users consume.

According to IU Bloomington, CBD can potentially counteract THC’s psychoactive effects.

But IU says CBD levels in plants decline as growers breed them to produce higher levels of THC.

IU says the researchers will study CBD to determine whether there are harmful side effects and how it might protect developing brains from adverse consequences of THC exposure during adolescence.