$2million NIH grant to study cannabis in adolescents

Researchers in the US have received more than $2million from the NIH’s National Institute on Drug Abuse to study the impact of cannabis use during adolescence.

The current research into the impact of adolescent cannabis use on mental health is conflicted.

While some scientists have found evidence that suggests it could lead to psychosis and conditions such as schizophrenia in later life, other recent research appears to have disputed these findings.

Researchers at at the Indiana University Gill Center for Biomolecular Science are now aiming to gain a deeper understanding of the effects of teenage cannabis use with a $2million grant from the National Institutes of Health (NIH).

The team of neuroscientists are specifically focused on studying cannabis use in adolescents aged 12 to 14, during this critical period of brain development.

Hui-Chen Lu, director of the Gill Center and a professor in the IU Department of Psychological and Brain Sciences said there is a “significant public health concern” associated with cannabis strains that are bred for increased THC content.

“It’s very different and much riskier than the more traditional strains used in the past,” Lu said.

“There’s an urgent need to understand the effects of these new strains.”

Ken Mackie, a Jack and Linda Gill Chair of the Gill Center and a professor in the Department of Psychological and Brain Sciences, said some studies indicate that heavy use of cannabis with high THC – particularly cannabis use that begins between ages 12 and 14 – could increase the risk of schizophrenia and other psychotic disorders from two- to five-fold.

“One of the functions of the prefrontal cortex is working memory, as well as processes like planning and impulse control,” Mackie said.

“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.”

The researchers have chosen to work with mice with diverse genetic backgrounds to mimic human diversity.

Unlike in past studies, they’ll also be using both male and female mice to see if there are sex-dependent differences in THC effects. They will be studying the underlying molecular changes that account for behaviour changes, like working memory deficits.

“If there are sex-dependent changes, we need to know what those are,” Lu said.

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

Lu and Mackie will also be studying CBD as earlier work from IU Bloomington suggests that CBD might protect from THC’s negative effects. The researchers will explore how CBD could protect the developing brain from the adverse consequences of adolescent THC exposure.

“Our brain is not wired precisely from the beginning,” Lu said.

“To properly develop, it needs to combine inputs from our environment, our experiences and our interactions with others. In particular, a properly configured prefrontal cortex is very important for goal-directed behaviour and social interactions.

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

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