The effects of childhood abuse and lack of parental affection can last a lifetime, taking a toll both emotionally and physically.
There are many reports assessing the psychological damage resulting from childhood abuse, and the effects on physical health have also been well documented. For instance, this "toxic" stress has been linked to elevated cholesterol, cardiovascular disease, metabolic syndrome and other physical conditions posing a significant health risk. The research into the physical effects of abuse, however, has focused on separate, individual systems.
A new UCLA-led study for the first time examines the effects of abuse and lack of parental affection across the body's entire regulatory system, and finds a strong biological link for how negative early life experiences affect physical health. The study is published online by the Proceedings of the National Academy of Sciences.
"Our findings suggest that there may be a way to reduce the impact abuse has, at least in terms of physical health," said Judith E. Carroll, a research scientist at the Cousins Center for Psychoneuroimmunology at UCLA, and the study's lead author. "If the child has love from parental figures they may be more protected from the impact of abuse on adult biological risk for health problems than those who don't have that loving adult in their life."
The researchers studied 756 adults who had participated in a study called Coronary Artery Risk Development in Young Adults (CARDIA). They measured 18 biological markers of health risk, such as blood pressure, heart rate, stress hormone, cholesterol, waist circumference, inflammation, and blood sugar regulation, and added up their risks across these markers to create a summary index called "allostatic load." Values at the upper range across these markers indicated they were at higher biological risk for disease. Previous research has shown that higher levels of allostatic load are associated with increased likelihood of a negative health event such as a heart attack or stroke, or show declines in physical or cognitive functioning.
To determine the study subjects' childhood stress the researchers used a well-validated self-report scale called the Risky Families Questionnaire.
They found a significant link between reports of childhood abuse and multisystem health risks But those who reported higher amounts of parental warmth and affection in their childhood had lower multisystem health risks The researchers also found a significant interaction of abuse and warmth, so that individuals reporting low levels of love and affection and high levels of abuse in childhood had the highest multisystem risk in adulthood.
The researchers suggest that toxic childhood stress alters neural responses to stress, boosting the emotional and physical arousal to threat and making it more difficult for that reaction to be shut off.