Abuse Victims More Stress-Sensitive

B O S T O N, Aug. 1, 2000 -- The horror of childhood abuse can often linger for a lifetime, with higher rates of depression, anxiety and drug abuse found among abuse survivors. But researchers have never fully understood why.

Now, a group of psychiatrists at Emory University are exploring the biological basis for that heightened vulnerability, hoping to develop new drug therapies that could assuage — and even prevent — it.

“We know that adults who were victims of child abuse are more prone to depression and anxiety problems,” says Dr. Jeffrey Newport, assistant professor of psychiatry and behavioral science at Emory University’s School of Medicine in Atlanta. “We wanted to investigate what might be underlying that vulnerability, and, down the road, provide some protection.”

In a study published today in the Journal of the American Medical Association, researchers led by Dr. Charles Nemeroff, also of Emory University, examined a small group of 49 women, ages 18 to 45.

The women fell into four separate categories: women who had been physically or sexually abused as children and currently suffered from depression; women who had been abused but were not currently depressed; women who had not been abused as children but currently had depression; and women who had not been abused and were not depressed.

Stress Test

All the women were subjected to a simulated “social stress test,” where they performed math problems and a mock job interview in front of an audience while having their heart rates and their levels of stress hormones monitored.

“Both groups of women who were abused, depressed or not, had elevated stress hormones,” Newport says. “Our interpretation is that the early life abuse sensitizes a stress system. Once a new stress situation occurs, those individuals are more sensitized to the effects of the situation.”

All of us have a certain vulnerability to stress that, once exceeded, can manifest itself in illness, such as depression or anxiety. But for these women, researchers say, the threshold of how much stress they can tolerate has been lowered; the abuse has rewired their stress hormonal systems to be either hyperactive or oversensitive.

Stress Hormonal System When we are faced with stressful situations, our hypothalamus produces a hormone called corticotropin-releasing factor, or CRF. That in turn, induces the pituitary gland to increase the release of adrenocorticotropic hormone (ACTH), which tells the adrenal gland to release more cortisol. These two hormones are the biological measurements of stress.

In these women, the researchers hypothesize, the signal to release CRF seems to go off too easily, causing these stress hormones to flood their system and produce symptoms associated with depression and anxiety, such as decreased appetite and feelings of fear.

“People need to realize that environmental stimuli can imprint themselves on the brain in a way that affects the body forever,” says Dr. Philip Gold, chief of the clinical neuroendocrinology program at the National Institute of Mental Health.

But David Finkelhor, director of the Crimes Against Children Research Center at the University of New Hampshire, warns against alarming women with a history of abuse.

“It is important we not frighten people who have a history of this into thinking their brains have been permanently damaged, and they should start taking some medication, even in the absence of any disturbance,” he says. “I think that would be very inappropriate.”

New Understandings But Gold says people should take comfort in the fact that scientists are beginning to understand the biological changes that occur after such terrible events and perhaps even be able to prevent them.

“They should not be hopeless,” he says. “These are biological changes that can be addressed by current medications and psychotherapy.”

And now, researchers at Emory and elsewhere are developing what are known as “CRF antagonists” to dampen the signal that releases these stress hormones. Nemeroff’s group is currently conducting follow-up trials on the drugs in Europe.

Although these drugs are probably a decade away, psychiatrists say this class of medication might also help the 20 to 30 percent of patients who have proven unresponsive to traditional depression drugs like Prozac and Zoloft, which concentrate on neurotransmitters in the brain rather than on the hormone-producing glands. Some of these patients may in fact have systems that are overproducing CRF.

“The upcoming ‘CRF antagonists’ are particularly exciting,” says Dr. David A. Baron, chair of the psychiatry department at Temple University School of Medicine. “I am convinced they will be the next major breakthrough in the pharmacological treatment of depression.”