So what becomes of children who grow up in trauma? Childhood adversity, i.e. being abused, neglected or exposed to violence, has long been known to have long term health effects on scientists. Its impact on the heart is one of the most urgent issues: childhood trauma has been associated with an increased risk of cardiovascular disease during adulthood. Less is known, however, about the impact of trauma on risk behaviors and cardiovascular health in adolescence, when habits and health trajectories are initially established.
Published in the Journal of Child Psychology and Psychiatry (2025), a new study by the 2004 Pelotas Birth Cohort in Brazil offers some of the only longitudinal evidence by a low and middle income country (LMIC). It reveals the impact of trauma on behaviors in adolescence such as smoking, drinking, and drug use and presents unexpected information about cardiovascular health.
The Study at a Glance
Population: 4,229 teenagers who were born in Pelotas, Brazil, in 2004.
Exposure to trauma: 81.9% had been exposed to at least one trauma at age 18.
Measures of behavior at 18: alcohol misuse, cigarette smoking, illicit drug use, sleep duration.
Cardiovascular parameters: resting HR (heart rate) levels and blood pressure (BP).
Scholars followed birth to age 18 exposure to trauma and associated it with health and lifestyle outcomes. Age 18 years: Approximately one out of 3 teenagers had a problem with drinking, approximately 9% were cigarette smokers, and 27% had been using illicit drugs.
Trauma and Teen Risk Behaviour.
The results indicate a dose response relationship: the greater the amount of trauma adolescents were exposed to, the greater the risk they had of using substances.
Age 15 trauma raised the likelihood of problematic alcohol use, smoking and drug use 25-44.
At age 18, trauma accounted for 36.8 percent of adolescent drinking, 59.1 percent of smoking and 27.9 percent of drug use.
Surprisingly, trauma was not associated with the duration of sleep.
This shows that trauma does not only cause emotional wounds, but it also defines the behaviors that may aggravate chronic health. The authors note that preventing trauma or providing support to the children who have been affected could greatly decrease substance use rates among teens.
The surprise heart discoveries
The most surprising finding, perhaps, was that exposure to more trauma was also associated with a lower blood pressure and resting heart rate at age 18.
The average resting heart rate of teens with three or more traumas was nearly four beats lower than controls.
It was also found that smoking and alcohol use were related to decreased blood pressure, which is the opposite.
This is contrary to the well known adult evidence that trauma increases cardiovascular risk. What could be the reason which causes adolescents to exhibit the reverse?
According to researchers, there are possible explanations:
Developmental timing: Trauma can have different impacts on adolescent physiology when compared to adult systems.
Externalizing behaviors: Antisocial behavior and substance use have been associated with low resting heart rate in teens.
Measurement limits: simple markers are HR and BP; more comprehensive tests of the cardiovascular system can indicate other outcomes.
The authors emphasise that such results do not imply that trauma is protective. Instead, they emphasize that the interaction of stress and biology is more complex at various stages in our life.
Why This Study Matters
Target LMICs: LMICs are often exposed to a greater number of traumas, yet most trauma studies are conducted in wealthy nations. This is an essential evidence gap covered by this Brazilian research.
Adolescent window: It is during adolescence that risky behaviors start. The role of trauma can be understood to influence timely interventions.
Policy implications: A significant fraction of substance-using teens could be prevented by reducing exposure to trauma and reducing disease burden in the future.
Practical Consequence: The Pelotas Peace Accords
The paper also mentions the local projects such as the Pelotas Pact for Peace, released in 2017. This is a city wide program that focuses on urban violence by reforming health, education, and justice. Violent crime has been lowering since its introduction in Pelotas, demonstrating that interventions organized at the community level can help to reduce exposure to trauma at the community level.
Lessons that Parents, Educators, and Policymakers Should Learn
Early trauma matters. Childhood adversity can be prevented, which will help lessen smoking, drinking, and drug use later in life.
Support systems help. Children who have been exposed to trauma require specialized mental and behavioral care in their adolescent years.
More research is needed. These unexpected cardiovascular results highlight the importance of longitudinal research that would trace the impact of trauma on heart health in adulthood.
Conclusion
This historic Brazilian Pelotas Cohort study demonstrates that childhood trauma is a strong predictor of substance use in adolescence and explains up to 59% of smoking. The connection between trauma and cardiovascular health in teens is confusing, but the message is clear: treating trauma at a young age may alter the future health of adolescents.
Prevention and trauma informed intervention is more than a strategy to safeguard mental well-being; it can also determine healthier health outcomes for whole generations.
References & Resources
Bailey, M., Fairchild, G., Hammerton, G., et al. (2025). Childhood trauma, adolescent risk behaviours and cardiovascular health indices in the 2004 Pelotas Birth Cohort. Journal of Child Psychology and Psychiatry. https://doi.org/10.1111/jcpp.14173
World Health Organization (2024). Cardiovascular diseases (CVDs) fact sheet.
Pelotas Pact for Peace: peaceinourcities.org