Childhood trauma linked with poor adolescent mental health outcomes

A cross cultural study from researchers in Brazil and the UK has revealed a strong connection between childhood trauma and the development of psychiatric disorders in adolescents living in low-and middle-income countries.

The research findings are based on the 2004 Pelotas Birth Cohort, Brazil, which has tracked more than 4,000 children born in Pelotas, a city in the southern state of Rio Grande do Sul, from birth to 18 years of age. Published in The Lancet Global Health, the study looked at how trauma exposure from childhood affects risk for mental health disorders during adolescence.

The results showed that by age 18, 81 per cent of the adolescents had been exposed to some form of trauma, such as witnessing a violent crime, abuse or neglect. The more different types of trauma experienced, the greater the chances of adolescents developing mental health problems, particularly anxiety, mood, and conduct disorders. 

By the age of 18 years, one third of all mental disorders were potentially explained by trauma exposure.

The new study builds upon the researchers’ earlier findings in the same cohort, which showed that one in three children living in Pelotas were exposed to trauma by 11 years of age, and that trauma was linked to the emergence of common childhood mental health problems.

“Our findings show that childhood trauma has a lasting impact on mental health, particularly in low- and middle-income countries where trauma is very common,” Lead researcher Megan Bailey said.

“In combination with previous studies that have also shown these effects in both young people and adults in high-income countries, it is clear that childhood trauma exposure is a key risk factor for developing mental health problems across the board.” 

“Our finding that trauma accounts for at least 31 per cent of all mental health problems by 18 years of age further underscores this relationship. Early interventions are critical to reduce exposure to trauma and help those most at risk of developing mental health disorders.”

In Pelotas, a city-led intervention programme, the Pelotas Pact for Peace, was launched in 2017 to reduce urban crime and violence through health, education, and criminal justice system projects. Early evaluations of this intervention showed lower rates of violent crimes after the intervention was implemented, though more research is needed to establish whether it also reduces the prevalence of mental health problems in young people.

This new analysis was funded by a studentship awarded to Megan Bailey by the University of Bath and the South-West Doctoral Training Partnership (Economic and Social Research Council) and by projects funded by the Brazilian National Research Council (CNPq; 409224/2021-9) and the Research Support Foundation of the State of São Paulo (FAPESP)/ Economic and Social Research Council/UK Research and Innovation (UKRI; 2023/12905-0).

Access the findings in full here.