Children are not only cared for, scolded, rewarded, and punished. They are also theorized about—and those theories change with time. Adults have concluded, variously, that children are in constant spiritual danger, or that they are inherently close to God, or that they are blank slates. Around the turn of the 20th century, some Western health professionals decided to gather data on children by studying how they grow. One of the first to do so, psychologist and pediatrician Arnold Gesell, MD, PhD, spent his most influential years at Yale, founding in 1911 what later became Yale Child Study Center. Gesell’s then-novel interest in children’s development, and the insistence of his successor Milton Senn, MD, on a cross-disciplinary approach, established traditions of curiosity and collaboration at Yale that have long influenced the world of child mental health. Today’s Yale Child Study Center is a leader in the study of such topics as varied as pediatric trauma, psychopharmacology, autism, mind-body connections, and how early childhood experiences and environmental influences affect health throughout the lifespan. One of its unifying principles is that children’s mental and physical well-being aren’t separate. That insight informs the close ties between the center and the Department of Pediatrics, according to Yale Child Study Center Chair Linda Mayes, MD. “[Pediatrics Chair Clifford Bogue, MD] and I are keen to continue to work closely together and to bring the departments together,” said Mayes, who is Yale Child Study Center’s Arnold Gesell Professor of Child Psychiatry, Pediatrics, and Psychology. “We really have a hope for an agenda about child health. Not child physical health, not child mental health—child health.” Where child mental health begins As an assistant professor in Yale University’s Department of Education, Gesell founded a children’s clinic in 1911. At the time, he was one of very few scholars of child development to study babies, and he used new tools like photography to investigate developmental milestones. In 1934, his groundbreaking Atlas of Infant Behavior provided these milestones for parents’ reference. Gesell spoke out against scolding and physical punishment and advocated for child welfare reform. Though not all his views have aged well—he favored eugenics, even while supporting environmental interventions like preschool programs—his approach offered an alternative to authoritarian parenting guides and guilt-inducing psychoanalytic theories. Upon Gesell’s 1948 retirement, Senn assumed leadership of the children's clinic, which became the Child Study Center, and later was named chair of the Department of Pediatrics. Senn not only helped entwine the two departments, he also widened the center’s focus to include social workers and educators, initiating the interdisciplinary emphasis that continues today. Supporting traumatized children In fall 2021, the American Academy of Pediatrics declared a state of national emergency in child and adolescent mental health. COVID-19 and its widespread death and disruption had poured fuel on an existing crisis, with rates of depression, anxiety, and suicidal behavior climbing in young people years before the pandemic. Many such mental health problems arise after trauma and early-life adversity, according to Mayes; without intervention, affected children may face lifelong poor health. “We as humans have a pretty adaptive biology. But you can bend a tree so that it breaks,” Mayes added. Still, there are ways to help bolster that tree. Yale Child Study Center has a long history of caring for pediatric trauma survivors. The late Donald J. Cohen, MD, Yale Child Study Center’s 1980s- and ’90s-era director and one of his generation’s leading child psychiatrists, developed an extensive international network of collaborators to improve the care of traumatized children around the world. Steven Marans, MSW, PhD, Harris Professor in the Child Study Center and professor of psychiatry, renowned for training police to work sensitively with traumatized children, co-directs the Yale Center for Traumatic Stress and Recovery, which develops new trauma interventions and provides direct services to children who have witnessed or experienced violence. Many of those kids come Marans’ way via emergency physician Kirsten Bechtel, MD, professor of pediatrics (emergency medicine) and of emergency medicine. Bechtel, an expert in caring for traumatized and abused children, works alongside Yale Child Study Center fellows to care for troubled and suicidal children who come to the Emergency Department. She is partnering with Yale Child Study Center faculty to develop ways to prevent abusive head trauma—including a 90-second video to help new parents cope with frustration—as well as on legislation to limit children’s access to firearms. “We’re trying to find where we naturally have overlap, and then garner our forces to work together,” Bechtel said. “We’re lucky—we have lots of resources at Yale, and we’re lucky that we have folks who are studying behavioral health.” Facing uncertain futures Arguably, climate change is the greatest crisis younger generations face, and anxiety related to its potential effects is a growing topic of psychiatric research. Associate research scientist Laelia Benoit, MD, PhD, studies how children and adolescents in France, Brazil, and the United States perceive and feel about climate change. They are alarmed but not paralyzed, she’s found, and they’re keen to take action. Furthermore, they respond positively to messages of hope and collective climate action, such as inspiring stories of change on social media. “We are focusing on making sure that the new narratives are something that helps you feel empowered, have fewer mental health issues, and take concrete action at your local level, using media that young people actually use, like TikTok or Instagram,” Benoit said. Amid societal inequity, some of today’s children will go on to lead much healthier lives than others. The divergence starts young. How exactly early-childhood experiences affect lifelong health fascinates associate research scientist Amanda Dettmer, PhD, who studies those questions using nonhuman primates. There are striking similarities between human and monkey infants. Both experience difficult health if they are born into worse social situations or if their attachments to caregivers are disrupted. But, Dettmer said, “What’s been really hard to determine in humans is why.” Using a vast data set and biobank from her previous work with monkeys at the National Institutes of Health, Dettmer is working to tease out the biological processes that tie early experiences to lifetime health. So far, it has become clear that infant monkeys with disrupted attachment tend to be hyper-responsive to stress, while the immune systems tend to falter in infant monkeys who are lower ranking in the troop. Dettmer expects a more detailed picture to emerge in time. Because monkeys reach adulthood in just a few years, Dettmer has data ready to analyze across the lifespan. All of it is relevant, and all of it begins in infancy and childhood. “One of my grants is from the National Institute on Aging,” Dettmer noted—hardly the norm in a pediatric department. “It’s just a reflection of the way the science is moving, which is much more collaborative—and understanding that studying lifelong health is really important.” Jenny Blair, MD is a frequent contributor to Yale Medicine Magazine.