A review of four decades of youth data found little change in overall symptom burden, but shifts in specific problems.
Researchers examined population-based samples of children and teenagers aged 1 to 18 from around the world. The studies used the Child Behavior Checklist, completed by parents, teachers or young people themselves, to compare symptom levels across data collected over four decades.
Overall symptom burden stayed broadly stable, although some groups showed decreases. The makeup of symptom profiles changed: externalizing problems such as aggression generally declined in several groups, while some reports pointed to increases in anxiety, depression, social problems or somatic complaints.
How symptom patterns changed
Across 175 studies and 418,528 participants, overall symptom burden did not change over the 40-year period, apart from some decreases in early childhood based on parent reports, middle childhood based on self-reports, and teenage boys based on self-reports.
The strongest multi-informant findings showed decreases in externalizing problems, including aggression in middle childhood, and decreases in internalizing problems among boys and girls in middle childhood. Other changes appeared in only one type of report: parent reports indicated more anxiety and depression in teenagers and fewer rule-breaking behaviors, while self-reports indicated more somatic complaints in teenage boys and fewer withdrawn or depressed symptoms overall. Self-reported social problems increased among European teenagers.
Results for attention and thought problems conflicted across informants. Attention problems appeared to increase in parent reports but decrease among middle-childhood boys in teacher reports. Thought problems increased in parent reports but decreased among teenage boys in self-reports.
Evidence and caveats
This was a pre-registered cross-temporal meta-analysis of population-based samples, using data collected from 1981 to 2019 and a standardized, cross-culturally validated checklist. It included parent, teacher and self-reports and examined age, sex, response rate and continent as possible influences.
The study measured subclinical mean symptom levels rather than diagnosing mental disorders, and the results compare groups studied at different times rather than following the same young people across generations. Several findings depended on a single type of informant, and some measures pointed in opposite directions depending on who reported the symptoms. The researchers said attention-problem results should be interpreted cautiously because the reliability of that subscale declined over time and there was evidence that it may not have measured the same way across periods. The analysis also did not examine changes after the COVID-19 pandemic.
// Source
Clinical Child and Family Psychology Review · 2026 · DOI: 10.1007/s10567-026-00574-6
Authors: Boglarka Vekety, Zsófia K. Takács, Tamás Kói, John Protzko, Heather C. Whalley, H. N. Alexander Logemann
Institutions: Vrije Universiteit Amsterdam, Semmelweis University, University of Edinburgh, Eötvös Loránd University, Central Connecticut State University, Budapest University of Technology and Economics, MRC Centre for Regenerative Medicine
