There are few times in one's life that bring more change and upheaval than puberty; it comes with a vast array of alterations to our biology, behavior, appearance, and emotions.
Puberty can be a challenging time for anyone and at any age, but for the girls who make this transition earlier than average, the struggle can be even more significant.
Previous studies have shown that an early first period, or menarche, is linked to mental health issues such as depression, anxiety, eating disorders, substance use, and poor school performance in adolescence.
Although this relationship has been studied intensively, the exact causes are not understood. But they are probably many-fold.
As the body changes, so too do social roles and relationships. Girls who make the transition sooner may have more complex social interactions, causing increased cognitive and emotional strain.
There are also certain changes in the brain that, if they occur early, might somehow increase susceptibility to psychological problems.
The impact of early menarche in adulthood
Despite hundreds of studies investigating the relationship between early menarche and adolescent mental health, very few have investigated its influence as the individual progresses into adulthood. A recent paper, published in the journal Pediatrics, set out to fill this gap.
The current study used data from the National Longitudinal Study of Adolescent Health, following nearly 8,000 women across 14 years. Depression and antisocial behavior, such as drug-taking, stealing, and other illegal activities, were tracked.
Girls who had experienced menarche earlier than their peers were more likely to have depressive symptoms and demonstrate antisocial behaviors in adolescence and as young adults (roughly 28 years old).
In fact, the effect was almost as strong in adulthood as it was during adolescence. The authors conclude:
"These findings indicate that the emotional sequelae of puberty extend further than documented in previous research, and suggest that earlier development may place girls on a life path from which it may be difficult to deviate."
Why does early puberty increase risk?
Long-term psychosocial health is probably affected by early menarche in a number of ways. Because hormonal, physical, and emotional changes are so pronounced, picking apart the individual role of each is challenging.
A factor that might partially be able to explain why depression caused by early menarche persists into adulthood is that experiencing one bout of depression increases the risk of having more. So, simply experiencing depression once (for any reason and at any time) makes having it again more likely.
Also, the onset of depression in childhood or adolescence is associated with increased symptom severity and more frequent recurrence.
The authors explain another potential influencing factor: "Because adolescence often serves as a foundation for future life events, girls who experience psychopathology during this time may be more likely to face compromised career and educational options, related life stressors, and feelings of futility regarding potential improvements or changes to their lives."
Peer relationships are also likely to be involved; getting along with less physically developed peers might be more stressful, for instance. This could increase the chance of forging friendships with older peers, which is associated with antisocial behavior.
The findings are concerning, especially as the average age of puberty has declined significantly in the past 50 years. The researchers hope that they might raise awareness of the potential risks of early puberty. Perhaps more attention might be paid to early signs of mental health issues in the girls.
However, the authors also relay certain limitations of the current project; for instance, gathering the participants' age of menarche was reliant on self-reports. Furthermore, of the potential range of psychosocial parameters, only antisocial behavior and depression were measured.
The authors remind us that there are still large gaps in our knowledge that need to be investigated. They write, "A challenge for future researchers is to specify the cognitive, social, neural, and biological mechanisms that mediate this continued risk."
Because the new findings build on — as well as confirm — previous studies, their conclusions are worrying. Hopefully, as our understanding improves, early interventions might be designed that reduce the risk of mental health problems for women who experience early puberty.