In new insight into adolescent brain development, Canadian investigators say a single gene responsible for dopamine connectivity may influence the development of numerous psychological disorders, including schizophrenia, depression, and drug addiction.

Falling something short of a unified field theory on teenagers, the newly isolated “teen gene” explains much about the adolescent media prefrontal cortex, at least in mouse studies. Cecilia Flores, a professor at McGill University, worked with colleagues at the Douglas Institute Research Center on the study.

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," Flores said in a statement. "Prefrontal cortex wiring continues to develop into early adulthood, although the mechanisms were, until now, entirely unknown."

As the adolescent human brain develops, even minor variations to the gene during teenage years produced significant differences later in prefrontal cortex function, the investigators said. In the study, they examined gene expression in the preserved donor brains of people who’d committed suicide, observing levels of gene expression 48 percent higher than others used as a control.

"The prefrontal cortex is associated with judgment, decision-making, and mental flexibility — or with the ability to change plans when faced with an obstacle," Flores said. "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."

By identifying the molecular trail head, investigators may now traverse further along the pathogenesis of some of these diseases, with onset in early adulthood. "We know that the DCC gene can be altered by experiences during adolescence," Flores. "This already gives us hope, because therapy, including social support, is itself a type of experience which might modify the function of the [teen] gene during this critical time and perhaps reduce vulnerability to an illness."

Psychiatrists say earlier therapy and support brought by speedier diagnoses would dramatically improve prognoses, into early adulthood and beyond.

Flores, Cecilia. Translational Psychiatry. Discovery Of 'Teen Gene' Could Hold Promise For Combating Severe Mental illnesses. 2013.