Every experienced pediatrician, child psychologist, and child psychiatrist knows this child: one week they're thriving, the next they refuse to eat, develop obsessive fears, experience motor tics, or explode in rage. Parents almost always describe it the same way: "A switch flipped." Many add something even more heartbreaking: "It's like I lost my child overnight."
For some families, that sudden change marks the beginning of months—or even years—of searching for answers. Children are often diagnosed with anxiety, obsessive-compulsive disorder (OCD), ADHD, eating disorders, or behavioral disorders. Those diagnoses may accurately describe the symptoms, but according to children's mental health expert Dr. Roseann Capanna-Hodge, they may not fully explain what's driving them.
Drawing on more than 30 years of clinical experience, analysis of more than 10,000 quantitative EEG brain maps, and her own family's experience navigating PANS and Lyme disease with her son, Dr. Roseann believes one question is too often overlooked: What changed biologically?
At NeuroImmune Day, a leading conference on neuroimmune health, Dr. Roseann will challenge clinicians to look beyond symptoms and consider how the nervous system, immune system, and brain interact when a child changes almost overnight. "When a child changes this dramatically, we have to ask a different question," says Dr. Roseann. "Not simply, 'What diagnosis fits these symptoms?' but 'What changed biologically that caused this child to change so suddenly?'"
For decades, many children experiencing sudden psychiatric or behavioral symptoms have been viewed primarily through a mental health lens. Today, a growing body of research—and the clinical experience of practitioners treating infection-triggered neuroimmune illness—is encouraging a broader conversation. Conditions such as PANS (Pediatric Acute-onset Neuropsychiatric Syndrome), PANDAS, Lyme disease, autoimmune encephalitis, and other neuroimmune disorders can trigger inflammation that affects the brain, immune system, and autonomic nervous system. For some children, the result is a dramatic change that appears almost overnight.
What looks like anxiety may be neuroinflammation. What looks like defiance may be a nervous system locked in survival mode. What looks like a psychiatric disorder may have an underlying biological driver that deserves further medical evaluation. Researchers estimate that PANS alone may affect as many as 1 in 200 children, yet many healthcare professionals receive little formal training in recognizing it.
"Parents often tell me, 'This isn't my child,'" says Dr. Roseann. "And they're right. These children haven't simply developed a behavior problem overnight. Something has changed in the biology that's driving their behavior."
One of the most frustrating experiences for families—and the clinicians caring for them—is watching children receive appropriate care while continuing to struggle. The infection has been treated, therapy has started, medications adjusted, yet some children remain stuck. According to Dr. Roseann, one important question is often overlooked: What state is the child's nervous system in?
"When the brain and body remain locked in chronic survival mode, healing becomes much more difficult," she explains. "The nervous system influences everything from emotional regulation and executive functioning to sleep, digestion, immune function, and a child's ability to benefit from therapy and medical treatment."
Rather than viewing the nervous system as simply another body system, Dr. Roseann describes it as the body's master regulator—continually communicating with the immune system, the gut, the endocrine system, and the brain. This understanding forms the foundation of Regulation First®, her clinical framework, which views nervous system regulation as a biological prerequisite for healing.
At NeuroImmune Day, Dr. Roseann will present "PANS/PANDAS and the Whole-Body Matrix: Why Dysregulation Isn't Just a Brain Issue," exploring how chronic nervous system activation influences immune function, sleep, gut health, vascular health, executive functioning, and emotional regulation. "We can't ask a child to heal while their nervous system still believes they're under constant threat," says Dr. Roseann. "Healing begins when the body finally receives the message that it's safe."
For parents whose child changes overnight, Dr. Roseann encourages not waiting. "Trust what you're seeing," she says. "Those changes deserve thoughtful medical evaluation and a conversation with clinicians who understand the connection between the brain, the immune system, and the nervous system."
Dr. Roseann's forthcoming book, The Dysregulated Kid: The Parenting Playbook for Helping Your Child Find Calm in a Chaotic World, published by Page Two Books on September 22, 2026, offers families practical tools based on the Regulation First® framework, including the Love Pause®, CALMS Protocol®, and 10-Minute Resets. "I wrote the book I wish every parent had the moment they realized, 'Something has changed, and I don't know what to do next,'" says Dr. Roseann.
