EDMONTON, Alberta, Feb. 2 (UPI) -- One in four older teenage girls will suffer at least one major depressive episode within the next four years, says a Canadian university study released Monday.
It has long been known females between 13 and 65 are twice as likely as males to suffer from depression, said psychologist Nancy Galambos of the University of Alberta, lead author of the study published in the latest edition of the International Journal of Behavioral Development.
But the level of depression Galambos and her team found among girls in their late teens was quite unexpected, the Globe and Mail reported.
The researchers monitored the mental health of 1,322 teenagers -- 648 boys and 674 girls -- between the ages of 12 and 19 over the course of four years.
They found 25 percent of girls between 16 and 19 experienced at least one major depressive episode within that four-year period.
Depression was defined as experiencing several of a range of symptoms over a prolonged length of time, including fatigue, irritability, inability to make decisions, sleeping problems, a lack of interest in day-to-day activities and suicidal thoughts.
