A new study conducted on mice shows that excess stress experienced during teenage years can lead to severe mental illness during adulthood.
Johns Hopkins researchers found that when a teenager experiences elevated levels of stress, he or she could suffer from serious cases of metal illnesses during adulthood. This is mainly because adolescence is a crucial stage in the growth and development of the brain.
"We have discovered a mechanism for how environmental factors, such as stress hormones, can affect the brain's physiology and bring about mental illness," said study leader Akira Sawa, M.D., Ph.D., a professor of psychiatry and behavioral sciences at the Johns Hopkins University School of Medicine. "We've shown in mice that stress in adolescence can affect the expression of a gene that codes for a key neurotransmitter related to mental function and psychiatric illness. While many genes are believed to be involved in the development of mental illness, my gut feeling is environmental factors are critically important to the process."
During the course of the study Sawa and his team found that when a health mouse was kept in isolation from other mice, it showed not behavioral problems. However, when a mouse that had a genetic predisposition to characteristics of mental illness was kept in a similar isolated place, it showed signs of mental instability such had hyperactivity. They also observed that when this mouse was removed from isolation and put to live with other mice, it continued to showcase similar abnormal behaviors.
"Genetic risk factors in these experiments were necessary, but not sufficient, to cause behaviors associated with mental illness in mice," Sawa said. "Only the addition of the external stressor -- in this case, excess cortisol related to social isolation -- was enough to bring about dramatic behavior changes."
Through this study Sawa hopes to point out that proper care needs to be taken of teenagers, especially if they have mental illness in their families. Keeping them away from stress is extremely crucial.
The findings were published in the journal Science.
