Hidden Scars: How COVID Lockdowns Altered Teen Brains Forever

Research from the University of Washington revealed that COVID-19 lockdowns led to accelerated cortical thinning in adolescents, impacting brain development significantly.

This effect was more pronounced in females than males, raising concerns about long-term brain health. The study highlights the importance of social interactions during adolescence, a period critical for cognitive development and mental health, especially as social restrictions have exacerbated conditions like anxiety and depression among teenagers.

Impact of Lockdowns on Adolescent Brain Development

A recent study reported the somewhat alarming findings that the social disruptions of COVID-19 lockdowns caused significant changes in teenagers' brains.

Researchers at the University of Washington in Seattle used MRI scans to examine the adolescent brain's cortex — the folded outer layer responsible for complex thinking. They discovered that the typical age-related thinning of the cortex accelerated after the lockdowns, with girls showing more pronounced changes than boys.

What do these findings mean?

Science highlights adolescence as a critical stage for brain development. Many typical teenage behaviors stem from the brain cortex still maturing. During this period, key developmental processes occur, including the thinning of the cortex, which helps the brain become more efficient and better organized.

Groundbreaking research published in 2022 provided the first evidence of a crucial window of brain "plasticity" — its ability to adapt — in the frontal brain region. This area is essential for functions such as decision-making, problem-solving, short-term memory, and managing social behavior.

Given the evidence of this sensitivity of brain development in adolescence, is it possible that the pandemic lockdowns really did accelerate harmful brain aging in teenagers? And how strong is the evidence that it was due to the lockdowns and not something else?

To answer the first question, we have to realize that aging and development are two sides of the same coin. They are inextricably linked. On the one hand, biological aging is the progressive decline in the function of the body's cells, tissues, and systems. On the other, development is the process by which we reach maturity.

Adverse conditions at critical periods of our life, especially adolescence, are very likely to influence our aging trajectory. It is therefore plausible that the "accelerated maturation" of the teenage brain cortex is an age-related change that will affect the rate of brain aging throughout life.

So it seems there is an unpalatable and much more serious conclusion: the reported accelerated maturation – though serious enough – is not a one-off detriment. It may well set a trajectory of adverse brain aging way beyond adolescence.

The Role of Social Interaction in Brain Health

Now to the second question: the role, if any, of the lockdowns. One of the central pillars of brain health is "social cognition": the capacity of the brain to interact socially with others. It has been embedded in our brains for 1.5 million years. It is not an optional add-on. It is fundamentally important. Interfere with it and potentially devastating health consequences result, particularly in adolescents who depend on social interaction for normal cognitive development.

At the same time, adolescence is also a period of the emergence of many neuropsychiatric disorders, including anxiety and depression, with younger females at a higher risk of developing anxiety and mood disorders than males.

Devastating Consequences

The socially restrictive lockdown measures appear to have had a substantial negative effect on the mental health of teenagers, especially girls, and the new study provides a potential underlying cause.

There is little doubt that the pandemic lockdowns resulted in devastating health consequences for many people. To the litany of evidence, we may now add a particularly grim finding – that the developmental brain biology of our precious teenage population has been damaged by these measures.

But perhaps the main message is that the wider effects of single-issue health policies should be considered more carefully. In the case of the known damaging effects of social isolation and loneliness on brain health, it's not as if the evidence wasn't there.

Written by James Goodwin, Professor in the Physiology of Ageing, Loughborough University.

Adapted from an article originally published in The Conversation.

Reference: "COVID-19 lockdown effects on adolescent brain structure suggest accelerated maturation that is more pronounced in females than in males" by Neva M. Corrigan, Ariel Rokem and Patricia K. Kuhl, 9 September 2024, Proceedings of the National Academy of Sciences.
DOI: 10.1073/pnas.2403200121