Childhood trauma occurs when an individual experiences one or more of what are known as adverse childhood experiences. These experiences include physical, sexual, or emotional abuse, neglect, or household dysfunction in which one might grow up around mental illness, divorce, domestic violence, an incarcerated relative, or substance abuse. The ACE study determined that those who experience adverse childhood experiences are more likely to present with a higher incidence of negative health and behavioral outcomes as adults. This study helped reveal the lifelong consequences of childhood trauma. We also know that trauma can impact the structure and neurochemistry of the brain, resulting in a more intense fear response.