Hereditary behavior, symptoms of which appear during adolescence may be associated with adult cannabis use

While some teens try marijuana but do not go on to long-term use, others develop a potent potency use that leads into adulthood. A large new study shows that at least a small portion of the risk for developing into an adult marijuana user may be related to hereditary behaviors and symptoms that appear during adolescence.

The magazine Addiction published by researchers at Brown University and Emory University.

“Our analysis suggests that some early teenage behaviors and symptoms – such as depression, neuroticism and addiction – may be a hallmark for cannabis use later in life,” says Rohan Palmer, senior author of paper and associate professor in the Emory Department of Psychology, where he heads the Addiction Behavioral Genetics Laboratory.

Decades of research have shown that behavior can be a genetic component. And while there isn’t a single genetically influenced trait that determines whether you’re going to be a long-term cannabis user, our paper reveals that polygenic effects are in many behaviors and possessive traits. shows a tendency for more risk. “

Leslie Brick, Lead Author and Associate Professor, Department of Psychology and Human Behavior, Brown’s Alpert School of Medicine

Brick, a longtime collaborator with Rohan, also holds an acclaimed faculty position in the Emory Department of Psychology.

The Transmissible Liability Register is a well-known measure for a constellation of hereditary symptoms that may appear in the developmental years associated with the risk of substance use disorder. For the mainstream paper, the researchers wanted to find out which of these inherited traits may be associated with marijuana use again later in life.

“There has been no less study of cannabis use than tobacco and alcohol,” Palmer says. “For one thing, it’s harder to get people to honestly answer detailed questionnaires about cannabis, because it’s an illegal substance. And it’s also much harder than consuming cannabis. normalization, as opposed to cigarettes and alcohol. “

The use of cannabis, however, is widespread among teenagers and young adults. In 2018, more than 35 percent of high school seniors surveyed reported using marijuana in the past year and more than 20 percent said they had done so on the job. last month, according to the National Institute on Drug Misuse (NIDA).

As cultural norms have shifted, with the legal introduction of marijuana for adult recreational use in many states, teens ’perceptions of the dangers of marijuana use have declined.

These risks, however, are real.

“Adolescence is a key period of brain development,” Brick says. “In fact, our brains will not stop developing until we are around 25 years old. Research shows that cannabis has some major effects on our biology, although not yet understands its full effects. “

The researchers drew data from the National Longitudinal Study of Adolescent Health, or Add Health, which includes a nationally representative sample of 20,000 teens in grades 7 to 12 in the United States last year. lead to adulthood. Comprehensive data from early adolescence to adulthood were collected on health-related health and behaviors, including substance use, personality, and genetics.

For the current paper, the researchers identified a large homogeneous subgroup of individuals from the Add Health study, approximately 5,000 people of European ancestry, for their final analysis sample. They then examined existing genome-wide association studies to examine whether certain traits of hereditary behavior identified during adolescence were related to the Transmissible Liability Register, and whether any of the these symptoms are also associated with risk for later cannabis use.

The results showed that a small proportion of the risk for cannabis use can be reversed into adulthood due to the genetic effects of neuroticism, risk tolerance and depression that can manifest during adolescence.

“While this work marks an important step in identifying genetic factors that may increase the risk for cannabis use, a significant proportion of the risk factors remain unexplained,” Palmer says. “We have shown how you can use the existing data to assess the potential of a polygenic risk score. More studies are needed to continue to identify genetic sources and other specific environments for long-term cannabis use risk. “

“A better understanding of the behaviors and traits that predispose someone to long-term cannabis use will give us a better view of identifying those most at risk so we can gain access. on effective interventions, “Brick says.

The main limitation of the current study, the researchers add, was that it focused on individuals of European ancestry, since sample size was not large enough for the genome-wide analysis available for ancestral groups. other.


Magazine Reference:

Brick, LA, et al. (2021) Intermediate role of adolescent sexual characteristics and behavior on the potential links between polygenic risk and cannabis use among young adults of European ancestry. Addiction.