## Virus Infection in Infancy May Trigger Depression Later in Life
A Japanese research team has discovered a potential link between a specific virus infection during infancy and the development of depression later in life. This finding challenges the long-held belief that inherited genes are the primary cause of depression.
The team, from the Jikei University School of Medicine in Tokyo, published their findings in a U.S. science journal in February. Their research focused on the human herpes virus type 6 (HHV6), which causes exanthema subitum, a common childhood illness characterized by a three-day fever.
Almost everyone is infected with HHV6 during infancy, and the virus remains dormant in the body throughout life. However, when an individual with the virus experiences stress or illness, HHV6 can become reactivated and spread from the mouth to the brain, causing reinfection. This process leads to the production of SITH1 proteins, which have been linked to an increased risk of depression.
one that readily produces SITH1 proteins and another that produces them less easily.
Their study of 28 patients with depression and 35 healthy individuals revealed that 68% of the patients were infected with the type of HHV6 that easily produces SITH1 proteins, compared to only 29% of the healthy group. Additionally, among the patients with the high-producing virus, 47% had family members with depression, suggesting a potential link between maternal transmission of the virus and increased susceptibility to the disorder.
This research suggests that the development of depression may be influenced by a combination of genetic and environmental factors, including early exposure to specific viruses. While further research is needed to fully understand the complex interplay between these factors, these findings offer new insights into the potential causes of depression and may pave the way for the development of novel prevention and treatment strategies.