Childhood difficulties can leave their mark for life
Ton Photography/Getty Images
People who have experienced severe adversity early in life appear to have higher amounts of a certain protein in their brains. mental health problems. Moreover, drugs targeting this protein may one day help mitigate these effects.
According to a US report, approximately one in five teenagers having experienced at least four potentially traumatic events in childhood, such as abuse, neglect, homelessness, or the death of a parent. Research shows it may affect brain development and increase the risk of mental illnesssuch as depression, and in adulthood.
“We still don't fully understand the mechanisms by which adversity or stress experienced early in life can have such long-lasting effects,” says Christophe Anacker at Columbia University in New York. “People who have experienced childhood trauma also tend to be less responsive to currently available antidepressants.”
Previous studies have shown that people with depression increased levels of SGK1 proteinor serum and glucocorticoid-regulated kinase 1 in their blood. Little is known about this protein, although it appears to influence how brain cells process and transmit information.
To better understand its effects, Anacker and his colleagues analyzed SGK1 in the brains of 50 men after they died, 36 of whom had committed suicide. All men completed a questionnaire about whether they had been physically or sexually abused before they were 16 years old.
The researchers found that in the hippocampus (an area of the brain involved in stress and memory), levels of the genetic material encoding SGK1 were on average about 33 percent higher in men who committed suicide than in those who did not, and even higher among those who also experienced suicide. childhood adversity.
In another part of the study, the team looked at more than 8,500 children aged 9 to 10 years and found that children diagnosed with depression were more likely to have increased activity of genes encoding SGK1, and this increased activity was also associated with childhood adversity.
Finally, the researchers injected 10 adult male mice with an experimental drug that inhibits SGK1 every day for 10 days. Thirty minutes after each dose, the animals were placed in a cage with an aggressive mouse for 5 minutes, which increased their stress levels.
After 10 days, the injected mice showed fewer signs of anxiety and depression than a separate group of mice exposed to an aggressive animal after the salt water injection. For example, former mice spent on average more than twice as much time in the center of an empty cage, rather than huddling in a corner, than control animals.
“When we reduce the level of SGK1 in this region of the brain, the hippocampus, the mice become more resilient to the effects of stress,” says Anacker. It appears that a similar pathway occurs in humans, so targeting SGK1 may help alleviate depression in people who have experienced difficulties early in life. It's not entirely clear how SGK1 might lead to poor mental health, but one explanation is that it prevents the formation of brain cells in the hippocampus.
The drug used in this study is not approved for use in humans, but other SGK1 inhibitors are in clinical trials for certain heart diseases. If they prove safe, they could be repurposed to treat mental illness, Anacker says. However, “such basic research in rodents is many, many steps away from the evidence that would be needed to say that we [an] a viable target for human treatment,” says Katie McLaughlin at Harvard University.
Do you need a listening ear? British Samaritans: 116,123; US National Suicide Prevention Lifeline: 1 800 273 8255; hotlines in other countries.
Topics:
