Roughly 13 percent of American teens have suffered from at least one episode of major depression – that equates to 3.1 million 12- to 17-year-olds. Now, a new study published in the Journal of Youth and Adolescence has investigated the patterns of depressive symptoms in teens over more than a decade, determining the differences between boys and girls. The findings could help clinicians better diagnose and treat cases of depression in youngsters.

The team turned to 5,409 adolescents involved in the UK’s Avon Longitudinal Study of Parents and Children. They followed them from the ages of 10 to 22, asking them to fill in a mood and feelings questionnaire at eight different points during the 12-year time period. The researchers then examined their answers, determining when depressive symptoms were strongest and increasing most rapidly.

“One possible explanation for increased depressive symptoms during adolescence is that young people face a number of social, psychological and biological changes during this stage of development,” the researchers note in their paper. “These changes include transitioning between schools, making new friends, taking exams and experiencing puberty.

“Efforts should be made to monitor individuals who show heightened depressive symptoms as they may be individuals at a greatest risk of depression or higher levels of depressive symptoms.” 

The results showed that at age 11, boys and girls have similar levels of depressive symptoms. However, up to the age of 20, girls experience a greater increase. After the age of 20, depressive symptoms were found to decrease in both sexes.

The researchers also found that depressive symptoms increased fastest in girls when they were 13.4 years old and quickest in boys when they were 16. The team thinks this difference may be related to the fact that girls tend to go through puberty earlier than boys. Boys and girls experienced their most intense depressive symptoms at similar ages, with girls’ depressive symptoms peaking at 19.6 years and boys’ at 20.4 years of age.

So why is this important? The researchers hope that knowledge of when teens are most likely to be suffering from depressive symptoms could help doctors treat and prevent depression in adolescents, a group that’s suffering from the condition more than the generations that came before them, at least in the US. (However, it should be noted that rises in depression could simply be a sign of better diagnostic methods and people being more likely to seek help.)

“These findings have implications for clinical services, schools and parents, who should be made aware that females are more likely to be younger when depressive symptoms are increasing most rapidly, with males following at a later stage,” the team writes.

While the results are certainly interesting, and provide information to medical practitioners, further research is needed to confirm the findings as this study is the first of its kind. Future studies might also help us explain exactly why boys and girls experience increases in depressive symptoms at different ages.

[H/T: BPS Research Digest]