Researchers warn early development may be linked to rising youth anxiety

High rates of anxiety in children and young people may be rooted in the earliest stages of life, researchers have warned.

The number of young people living with anxiety is rising. Rates are highest in developed countries.

Stress caused by the COVID-19 pandemic cannot fully explain this trend. While it did worsen mental health in young people, it had a lesser effect than many experts predicted.

Writing in Science, Professors Mark Hanson and Sir Peter Gluckman hypothesise that early biological adaptations may contribute to anxiety. Some of these adaptations happen even before birth. While they were once protective, the researchers suggest they may now be mismatched to modern life.

Professor Hanson is Emeritus Professor at the University of Southampton. He is also part of the NIHR Southampton Biomedical Research Centre (BRC)’s Nutrition, Lifestyle and Metabolism theme.

Professor Sir Peter Gluckman is based at the University of Auckland.

An evolutionary mismatch

Anxiety evolved as a survival tool. It can be understood as an internal alarm system to detect danger.

In pregnancy, early environmental signals can shape how a child’s brain responds to threats. These predictive adaptive responses prepare the body for the expected environment.

However, the new hypothesis suggests that the environments children are born into may no longer align with the environments they grow up in.

Signals in the womb or early childhood may suggest a harsh, threatening environment. Adaptations could misfire if a child then grows up in a fast-paced, digital world where threats are more social than physical.

This can result in heightened anxiety, poor emotional regulation and depression. It can also reduce their ability to handle everyday stress.

A critical window

The researchers challenge the traditional diathesis-stress model, which focuses on predisposition plus later-life stress.

Instead, they highlight the first 1,000 days - from pregnancy through early childhood - as the key period for shaping mental resilience.

The brain’s executive functions take shape in early childhood. A child’s ability to manage stress, build relationships, make decisions and maintain focus is largely shaped before the age of four.

Modern families face a range of pressures, including rising levels of maternal stress, limited caregiver interaction and the increasing presence of digital devices. These can all interfere with early brain development, priming children for dangers that may never appear.

Rethinking government policy

The researchers say that most government strategies for mental health begin too late as they miss the critical window of early development.

Professors Hanson and Gluckman are calling on policymakers to adopt a lifecourse approach. It includes:

• Prioritising maternal mental health during pregnancy
• Investing in responsive, high-quality early childhood care
• Shifting education and social policy to support early brain development

This is the approach taken by the NIHR Southampton BRC.