Why Cry-It-Out and Sleep-Training Techniques Are Bad for Babes

Abstract

Editorial In 1998, Dr. Dick Krugman, then Editor-in-Chief of the journal Child Abuse & Neglect, asked me to write a review of new studies coming out on the neuropsychology of trauma, with a particular focus on the long-term impact of childhood abuse. I was happy to do it. It was an exciting time in the child maltreatment/trauma field. With new technology, researchers could finally study living human brains. This technology opened up whole new worlds, and I had a chance to summarize these findings for the major journal in my field (Kendall-Tackett, 2000). The article took months to write. Since research in this field was so new, many of the findings were contradictory. For example, the physiological footprint of major depression was the exact opposite of the footprint for posttraumatic stress disorder (PTSD). How could that be? It was common for one person to have both. Researchers eventually developed better models that helped us understand these apparently contradictory findings. But in those first few years, they were hard to understand. One finding, however, was remarkably consistent across studies: chronic stress was bad for the brain. This was true for adults. And it was especially true for children under the age of five, whose brains are malleable, and therefore highly vulnerable to stress. As Bruce Perry found, ongoing childhood stress could permanently alter the way children's brains worked. Robert Sapolsky (1996) authored one of the classic articles on the effects of stress in the journal Science: Why stress is bad for the brain. In this article, he described the impact of the stress hormone cortisol on the hippocampus, the section of the brain involved in learning and memory. In in vitro studies, dripping cortisol on hippocampal cells made them shrink. In living human beings, those who experienced ongoing chronic stress or depression (which elevated cortisol levels), had smaller hippocampi than those without stress or depression. Doug Bremner and others have found a similar pattern with combat vets and sexual abuse survivors with PTSD (Bremner, 2006). There were many other studies with similar findings. But the bottom line is this: chronically elevated cortisol levels harm brain cells.