In 2008, social scientists at the Centers for Disease Control and Prevention conducted a study that looked at the effects of positive stress, tolerable stress, and toxic stress on children. The study looked at 17,000 adults of which almost 2/3 reported one type of stress and more than 20% reported multiple types of stress.
Positive stress was defined as causing minor psychological changes including an increase in heart rate and changes in hormone levels. This type of stress can be managed with help from caring adults. An example would be a child attending a new daycare.
Tolerable stress refers to adverse experiences such as the death of a loved one, family disruption from divorce, and other issues that can be managed with the support of caring adults. This type of stress may become positive stress or toxic stress if the child lacks adequate support.
Finally, toxic stress was defined as resulting from intense adverse experiences over a long period of time. This includes abuse and neglect. Here, the stress response system gets activated for a prolonged period of time and can lead to permanent changes in the brain and leave a person susceptible to infections and chronic health problems. Sustained toxic stress can lead to damage of the hippocampus, the area of the brain responsible for memory and learning.
This study found that participants who were sexually abused as children were more likely to experience multiple types of stress related issues. Those who witnessed intimate partner violence were 2 to 6 times more likely to experience another type of stress related problem. As the frequency of witnessing intimate partner violence increased, the chance of reported alcoholism, illicit drug use, IV drug use, and depression also increased.
Overall, the study found that exposure to physical abuse, sexual abuse, and intimate partner violence in childhood resulted in women being 3.5 times more likely to report intimate partner violence victimization. Exposure to physical abuse, sexual abuse, and intimate partner violence in childhood resulted in men being 3.8 times more likely to report intimate partner violence perpetration.