Scientists have found that a particular gene, known as DCC, is responsible for dopamine connectivity in the brain’s prefrontal cortex during adolescence. This gene is altered by experiences that take place during the teen years and may greatly affect the chances of developing major mental illness.
“We know that the DCC gene can be altered by experiences during adolescence,” said Cecilia Flores, Ph.D., senior author on the study and professor at McGill’s Department of Psychiatry.
“This already gives us hope, because therapy, including social support, is itself a type of experience which might modify the function of the DCC gene during this critical time and perhaps reduce vulnerability to an illness.”
Most signs of mental illness begin to appear during adolescence. During this phase of brain development, teens are particularly vulnerable to psychiatric disorders, including schizophrenia, depression and drug addiction.
“The prefrontal cortex is associated with judgment, decision making, and mental flexibility — or with the ability to change plans when faced with an obstacle,” said Flores.
“Its functioning is important for learning, motivation, and cognitive processes. Given its prolonged development into adulthood, this region is particularly susceptible to being shaped by life experiences in adolescence, such as stress and drugs of abuse. Such alterations in prefrontal cortex development can have long term consequences later on in life.”
In their previous research with mouse models, the researchers have shown that dysfunction of this gene during the teen years has behavioral consequences which carry into adulthood.
“Certain psychiatric disorders can be related to alterations in the function of the prefrontal cortex and to changes in the activity of the brain chemical dopamine,” said Flores. “Prefrontal cortex wiring continues to develop into early adulthood, although the mechanisms were, until now, entirely unknown.”
Even subtle changes in DCC during the teen years produce significant alterations in prefrontal cortex function later on. To see whether the findings could translate to human subjects, researchers examined DCC expression in postmortem brains of people who had committed suicide.
These brains did, in fact, show higher levels of DCC expression — some 48 percent higher when compared to control subjects.
Now that the researchers have identified the first molecule involved in how the prefrontal dopamine system matures, they now have a target for further investigation for developing pharmacological and other types of therapies.
Early therapy and support in the teen years — as soon as a mental health issue first manifests itself — offers far greater potential for a successful outcome and a healthy adulthood.
Source: Translational Psychiatry