Children Who Lost a Parent in the 9/11 Terror Attack Had Persistent HPA Axis Dysregulation

Marlene Busko

April 05, 2007

April 5, 2007 — A 2-year study found that, compared with a control group of nonbereaved children, children who lost a parent in the September 11, 2001 terror attack had persistent hypothalamic-pituitary-adrenal (HPA) axis dysregulation, shown by salivary cortisol levels. The bereaved children also had higher rates of anxiety, especially posttraumatic stress disorder.

The study is published in the April issue of Biological Psychiatry.

Lead author Cynthia R. Pfeffer, MD, from Weill Medical College of Cornell University in New York, New York, told Medscape: "The main findings were that the children who were bereaved had higher levels of cortisol that persisted over the course of the study, and they did develop higher rates of anxiety disorders.... Before 9/11 they were functioning quite normally."

The group aimed to conduct a prospective study to evaluate the longitudinal relation among severe psychosocial stress, psychiatric morbidity, and HPA axis function in children who lost a parent in the terror attack.

Dr. Pfeffer explained that the actions of the HPA axis go back to ancient times when the body responded to stress with a "fight or flight" reaction. Usually, cortisol levels (which are markers for the activity of the HPA axis) rise in response to stress and then slowly go back to normal. The group hypothesized that they would find persistent dysregulation in HPA axis functioning, as well as higher rates of anxiety and mood disorders, in bereaved compared with nonbereaved children.

The team contacted New York schools and police and fire departments to recruit children. The bereaved children had suffered the sudden unexpected loss of 1 parent during the September 11, 2001 terror attacks. The 45 bereaved and 34 nonbereaved children were matched for age (8.9 ± 2.9 years vs 9.3 ± 2.5 years, respectively) and other characteristics.

The children entered the study 4 months to 3 years after September 11, 2001 and were evaluated every 6 months for 2 years. The evaluation included a diagnostic interview (Child Schedule for Affective Disorders and Schizophrenia [K-SADS]) to determine the presence of psychiatric disorders. Their cortisol levels in saliva were also measured at baseline (from samples taken in the morning, at 4 pm, and at bedtime) and after the administration of dexamethasone (which suppresses cortisol).

Higher Rates of Psychiatric Disorders

Before the loss of a parent in the attack, only 31.8% of the bereaved children had experienced a psychiatric disorder (most commonly anxiety or attention deficit disorder), which was similar to the rate for nonbereaved children (35.3%). After losing a parent, and during this 2-year study, the rate of psychiatric disorders increased to almost 73% in the bereaved children, whereas the rate in the nonbereaved children remained the same. Posttraumatic stress, especially, was significantly higher in the bereaved group.

Psychiatric Disorders: Bereaved vs Nonbereaved Children

Disorder type

% of Bereaved Children

% of Nonbereaved Children










Posttraumatic stress








Persistently ElevatedCortisol Levels, Risk for Future Morbidities

Compared with nonbereaved children, bereaved children had persistently higher baseline morning and 4 pm levels of cortisol. Cortisol suppression after dexamethasone was less in bereaved than in nonbereaved children, but this was not statistically significant. The circadian rhythm of cortisol levels was maintained in all children throughout the study

Compared with bereaved children with no psychiatric disorders, bereaved children with posttraumatic stress disorder had significantly lower 4 pm baseline cortisol and significantly greater 4 pm suppression of cortisol with dexamethasone, "which may be due to sensitization of the glucocorticoid receptor resulting from severe stress," the group notes.

They write that the fact that, over the 2 years, psychiatric disorders declined but salivary cortisol levels remained elevated in the bereaved children "suggests that traumatic bereavement causes lasting changes in HPA axis regulation that persist even as the psychiatric disorders resolve." They add that further studies are needed to determine whether early identification and intervention can prevent this persistent abnormal neuroendocrine functioning in bereaved children, with its risk of future morbidities, such as cognitive impairment, reduced bone density, and insulin resistance.

Dr. Pfeffer said that the message for practicing clinicians is that "children who have lost a parent should have an evaluation, and clinicians should appreciate the fact that the child is likely to be under severe stress." It is also likely that the grieving parent needs to be assessed, she added. She emphasized that the researchers would like to acknowledge their gratefulness to the children and families who participated in this research.

Biol Psychiatry. 2007;61:957-965.


Comments on Medscape are moderated and should be professional in tone and on topic. You must declare any conflicts of interest related to your comments and responses. Please see our Commenting Guide for further information. We reserve the right to remove posts at our sole discretion.