Teens who smoke weed show vast differences in brain structure

Teens who smoke weed, drink alcohol or vape before age 15 have a different brain structure than teens who don’t, a study shows.

Researchers at Indiana University followed nearly 10,000 adolescents for two years, 35 percent of whom self-reported having used alcohol, marijuana and/or nicotine before the age of 15.

All participants also underwent brain scans which showed that those who had used any of the substances before the age of 15 had a thinner prefrontal cortex – a part of the brain associated with regulating emotions – compared to those who said they had used them at a young age. had not used drugs or alcohol. .

Those who said they had used substances at a young age also tended to have larger brains and greater subcortical volume, the area of ​​the brain related to memory, emotions, pleasure and hormone production.

Scientists said it was not clear whether the substances changed the teen’s brain or whether teens with certain brain characteristics were predisposed to trying substances.

The researchers concluded that varying brain structures may reflect the predisposition teens have to engage in substance use earlier in life, which “could have potential implications for the development of later problems.”

Dr. Nora Volkow, director of the National Institutes of Drug Abuse (NIDA), said: ‘This adds to emerging evidence that an individual’s brain structure, in addition to its unique genetics, environmental exposures and interactions between these factors, influence can be at the risk level. and resilience to substance use and addiction.

‘Understanding the complex interplay between the factors that contribute to and protect against drug use is crucial for informing effective prevention interventions and providing support to those who may be most vulnerable.’

For the study, published this month in JAMA network openedchildren were recruited from the Adolescent Brain and Cognitive Development study (ABCD study).

The study, set up by NIDA, aims to analyze the development of children’s brains and how it can be affected by certain factors, including drug abuse.

For the current article, children were recruited from 22 sites in the US and were nine years old at the start of the study.

They were followed from June 1, 2016 to October 15, 2018 and asked to self-report whether they had used substances.

Among the 3,460 respondents who admitted to using substances before their 15th birthday, alcohol was the most commonly used substance; 90 percent reported this.

About 62 percent of participants also reported using nicotine, while 52.4 percent said they had used marijuana before age 15.

In the analysis, adjusted for factors such as gender, the researchers identified five key whole-brain differences between the two groups – including different overall brain size.

These were that teens who said they had used substances tended to have a thinner prefrontal cortex, but a thicker cortex in all other lobes, such as the occipital lobe – the area of ​​the brain related to visual perception, including color, shape and movement.

The results also showed they had larger brains, a larger globus pallidus – a structure that regulates voluntary movements – and a larger hippocampus – a part of the brain that helps with learning and memory.

At a regional level, they also identified 39 differences between the two groups – with around 56 percent of these related to cortical thickness.

Of these, 22 of them (or 56 percent) were related to variations in cortical thickness, with the cortical layer being the outermost layer of the brain and important for higher-level processing such as language, memory and reasoning.

There were also some differences depending on the substance used, with those who used cannabis having lower right caudate volume – an area associated with the processing of visual information.

The researchers wrote in the study: ‘Our findings suggest that structural differences in the prefrontal cortex may predispositionally contribute to the early stages of substance involvement.

‘Our data cannot yet determine at which developmental point(s) substance-related variability in brain structure arose.

‘Large-scale longitudinal studies… that track neurodevelopment and substance exposure or involvement from the neonatal period through young adulthood are needed to address the origins of these differences.’

The rate at which teens use substances has experts concerned about the effects on brain development.

Previous research has found that excessive alcohol use in teens, or binge drinking, hinders the growth of brain areas related to impulse control, memory and learning, and also puts them at greater risk for depression.

Smoking marijuana at a young age can also affect the way the brain builds connections and thickens gray matter, which can cause lifelong problems with memory, attention and learning.

There are also suggestions that vaping nicotine could increase a person’s risk of dementia by narrowing the blood vessels that supply blood to the organ.

Researchers from the study published this month hope the data can be used to identify people at risk of substance use disorder early and trigger rapid interventions.