When childhood feels unpredictable, the brain remembers

UC Irvine-led study finds overlooked form of adversity can reveal hidden mental health risks in nearly 30,000 children

Orange, Calif. — For years, pediatricians have relied on a widely used checklist to identify children who have experienced traumatic events such as abuse, neglect or household violence. But a new UC Irvine-led study suggests that another, less visible form of adversity may be shaping children’s mental health, and it often goes undetected.

Researchers found that growing up in an unpredictable environment, where daily life lacks consistency and children are unsure what comes next, is strongly associated with depression, anxiety, sleep disorders and other mental health challenges. The findings, published in Nature Mental Health, are based on nearly 30,000 children receiving care through Rady Children’s Health pediatric clinics in Orange County.

The study also shows that asking children and families a handful of questions about unpredictability can identify many at-risk young people who would not have been recognized through traditional Adverse Childhood Experiences, or ACEs, screenings alone.

The work represents years of neuroscience research translated into a practical tool that could help pediatricians identify vulnerable children earlier and give families opportunities to intervene before problems become more severe.

From the neuroscience lab to the doctor’s office

The project brings together neuroscientists, psychologists, pediatricians and data scientists from UC Irvine, Chapman University and Rady Children’s Health, demonstrating how discoveries about the developing brain can move beyond the laboratory and into everyday clinical care.

At the center of the research is Dr. Tallie Z. Baram, UC Irvine Donald Bren Professor and Distinguished Professor of pediatrics, neurology, and anatomy and neurobiology, as well as Danette Shepard Chair in Neurological Studies. For decades, Baram has studied how early-life experiences influence brain development.

Her laboratory research revealed that developing brains rely on predictable patterns to build healthy neural connections — findings that now appear to extend to children’s everyday lives.

“What we discovered in the laboratory mice is that optimal development of the brain depends on consistent patterns, which enable the maturation of brain connections,” said Baram, the study’s senior author and co-corresponding author. “Like mice, children’s brain connections involved in happiness, threat and safety benefit from repeated, predictable experiences. This study shows that those principles matter not only in neuroscience research but also in the lives of children and families from a broad range of wealth and backgrounds.”

Looking beyond traditional measures of adversity

Traditional ACEs screenings focus on experiences such as abuse, neglect and family dysfunction. While those tools have transformed the understanding of childhood trauma, they do not capture every child who may be struggling.

The new study evaluated whether adding a simple five-question measure of childhood unpredictability could improve screening.

Researchers found that both traditional adversity and unpredictability were linked to higher rates of depression, anxiety, behavioral concerns, sleep disorders and physical symptoms including headaches and abdominal pain.

But unpredictability revealed something more.

Children who reported highly unpredictable lives were substantially more likely to experience depression than children who scored low on both measures, even when they had no traditional ACEs. The screening also proved especially useful in identifying children at risk for sleep disorders.

When researchers combined both screening methods, the relationship to mental health outcomes was often stronger than either tool alone.

“Traditional ACEs screening has helped our understanding of childhood adversity, but it fails to identify many children who are at risk for mental health problems,” said Laura M. Glynn, PhD, professor of psychology at Chapman University and co-corresponding author of the study.

“Our findings suggest that unpredictability is a distinct and meaningful form of adversity that contributes to risk in ways that existing screening tools do not detect, thus increasing our ability to target individual children.”

A statewide effort with national implications

The study grew out of a $2.9 million grant awarded in 2021 by the California Initiative to Advance Precision Medicine. Between 2021 and 2024, researchers incorporated the unpredictability questionnaire into routine pediatric visits at 19 Rady-affiliated clinics across Orange County.

California’s statewide ACEs screening initiative, the first publicly supported program of its kind in the nation, created a unique opportunity to test whether expanding childhood adversity screenings could improve care for families from diverse socioeconomic, ethnic and cultural backgrounds.

Nearly 30,000 children under age 18 participated, making the project one of the largest real-world studies examining how different forms of adversity affect a child's mental health.

Small routines can make a difference

Unlike many forms of childhood adversity, unpredictability is often something families and communities can influence.

Consistent bedtime routines, reliable caregiving, predictable schedules and stable daily patterns may all help create environments that support healthy brain development. Previous research by members of the team also found that predictable home environments helped buffer children from stress during the COVID-19 pandemic.

Baram emphasizes that the findings are not about perfection.

“For parents, this isn’t about creating a perfect home,” Baram said. “It’s about recognizing that consistency matters. Small routines and predictable patterns in daily life can support healthy development.”

As pediatricians increasingly look for ways to identify children before mental health problems escalate, the researchers say measuring unpredictability could become an important addition to routine care and provide families with another opportunity to support healthy development during the years when the brain is growing fastest.