Early puberty linked to depression in girls

Girls who go through puberty early could be more likely to experience depression and behaviour problems that last into their 20s compared to peers who start menstruation later, a U.S. study suggests.

Researchers studied data on nearly 7,800 women who had their first menstrual cycle at an average age of 12. The women were interviewed four times, starting around age 16 and continuing until about age 28.

Girls who went through puberty earlier than most were more likely to become depressed, and their symptoms were also more severe in adolescence, the study found.  

The younger the age at the first period, the stronger the association between early puberty and mental health problems; It was stronger for girls who started menstruation at age 8 than at age 10, for example.

With earlier puberty, girls were also more likely to have behaviour issues that led to things like stealing, lying, breaking into buildings and selling drugs. The link lasted into young adulthood.

Problems in adulthood

Interestingly, the magnitude of the association between puberty and these psychological difficulties remains stable, meaning that puberty is as strongly associated with depressive symptoms and antisocial behaviour during adulthood as it is during adolescence, said lead study author Jane Mendle, a researcher at Cornell University in Ithaca, New York.
 
This suggests that the psychological vulnerability of earlier puberty lingers longer than we previously may have expected, Mendle said by email. It's not simply a question of adolescent growing pains.

Sweeping changes in biology, appearance, self-perception and emotion combine to make puberty one of the most pivotal phases of development during the life span, the researchers note in Pediatrics. Although puberty can be a challenging time for all adolescents, it can be a particularly vulnerable time for girls who physically mature ahead of their peers.

Because physical maturation is linked to changes in social roles and relationships, this has long been linked to difficulties coping with new changes and stressors in life as well as changes in the brain that can make youth exceptionally vulnerable to mental health and behavior difficulties.

Researchers examined data from the National Longitudinal Study of Adolescent Health, a nationally representative study that includes youth from a broad range of racial, ethnic and socioeconomic backgrounds. The interviews examined in the current study were conducted in four waves from 1994 to 2008.

Questions focused on the timing of menstruation and also touched on symptoms of depression that the teens had experienced in the past week and the frequency of so-called anti-social behaviours like lying, stealing and dealing drugs.

Young women who experienced depression as adults may have been at risk because they were more likely to start experiencing these symptoms during adolescence and remained at risk over time, the study concludes.
 
With antisocial behaviours, the increased risk of acting out in adulthood after experiencing an early puberty wasn't as pronounced as it was for depression.

The study wasn't a controlled experiment designed to prove whether or how early puberty might influence the risk of 
depression or behaviour problems in adolescence or later in life.

Possible factors

It's also possible that a variety of factors not examined in the study, such as the impact of early puberty on academics or friendships, might at least in part explain the reason puberty timing appeared tied to the risk of depression and behaviour problems, the authors note.

From a social standpoint, girls who develop early tend to be treated like they are older than they really are, said Dr. Ellen Selkie, author of an accompanying editorial and an adolescent medicine specialist at the University of Michigan in Ann Arbor.

Sometimes, that means they might hang out with older kids to try to fit in, Selkie said by email.
 
But that also means they could be involved in things that they aren't really mature enough for, Selkie added. That sense of not really belonging can lead to mood problems and acting out — which we know can set up a pattern of behaviour that leads to adult problems as well.