Risk of Depression Increases Following Head Injury
DURHAM, N.C. - People with a history of head injury have an increased risk of depression for decades after the injury is incurred, and those with more severe head injuries appear to be at highest risk, according to an article in the January issue of the Archives of General Psychiatry.
Dr. Tracey Holsinger, from the department of psychiatry and behavioral sciences at Duke University Medical Center, and colleagues identified 1,718 male World War II veterans who served during 1944 to 1945 and were hospitalized during that time, and used military records to establish the presence and severity of head injury. Then, in 1996 and 1997, Holsinger and her colleagues interviewed the 520 veterans who had been hospitalized with head injury (mean age at which the head injury was sustained was 20.9 years) and 1,198 who had been hospitalized for other reasons to determine their lifetime history of depressive illness. Men with dementia were excluded from the study.
The study showed that lifetime prevalence of major depression was 18.5 percent in those with a history of head injury compared with 13.4 percent in those without.
"We found an association between head injury during early adulthood and lifetime prevalence of major and minor depression," Holsinger said. "This finding may not be surprising given the reports of increased rates of depressive symptoms shortly following head trauma."
The researchers also found that the prevalence of major depression was higher in younger compared with older patients.
According to background information in the article, more than 1.2 million Americans sustain head injuries annually. The mechanism by which brain injury might affect lifetime risk of depression is unclear and that disability after head injury may be attributed to physical, cognitive or psychological factors. Head trauma has been considered a risk factor in Alzheimer's disease and other dementias.
"Whether depression results from direct damage to [brain] regions or from response to the damage is unclear," Holsinger said.
"Our findings suggest that the effects of head trauma continue for decades after injury," she added. "The cost of depression to individuals includes shortened life span and decreased quality of life. The cost to society includes increased burden of illness, adding to the already extensive cost of brain injuries."
This study was supported in part by a grant from the National Institute on Aging, National Institutes of Health.
Joining Holsinger in the study were Duke colleagues Dr. David Steffens, Michael Helms and Brenda Plassman; Caroline Phillips, Dr. Richard Havlik and Dr. Jack Guralnik from the Epidemiology, Demography and Biometry Program of the National Institute on Aging; and Dr. John Breitner from the School of Public Health at Johns Hopkins University.