Teenagers who smoke weed, drink alcohol or vape before their 15th birthday have a different brain structure from those who do not, a study has found.
Researchers at Indiana University tracked nearly 10,000 adolescents for two years, of which 35 percent self-reported consuming any alcohol, marijuana and/or nicotine before age 15.
All participants also underwent brain scans that revealed those who had used any of the substances before 15 had a thinner prefrontal cortex — an area of the brain linked to regulating emotions — compared to those who said they had not used drugs or alcohol at a young age.
Those who said they had used substances young also tended to have larger brains overall and a greater subcortical volume, the area of the brain linked to memory, emotion, pleasure and hormone production.
Scientists said it was not clear whether the substances altered the teenager’s brains or if teens with certain brain characteristics were predisposed to try substances.
The researchers concluded that varying brain structures may reflect a predisposition teens have for engaging in substance use earlier in life, which could have ‘potential cascading implications for development of later problems.’
Dr Nora Volkow, director of the National Institutes of Drug Abuse (NIDA), said: ‘This adds to some emerging evidence that an individual’s brain structure, alongside their unique genetics, environmental exposures and interactions among these factors, may impact their level of risk and resilience for substance use and addiction.
‘Understanding the complex interplay between the factors that contribute and that protect against drug use is crucial for informing effective prevention interventions and providing support for those who may be most vulnerable.’