Most of us are familiar with a stage of puberty (that we probably hope we can forever push to the back of our minds and never re-live ever again, and desperately hope that when our own children reach that stage, that our partner will take over parenting duties for a few years…) called gonadarche. This is the more obvious phase of puberty where secondary sex characteristics appear and hormones that are released from the gonads (testosterone for boys, estradiol for girls) start to increase. For girls, these are responsible for the start of menstruation. Chronological ages for the start of this phase vary a lot (and interestingly, for girls, where the start of menstruation is an easy way to mark this onset, ages have been getting increasingly younger over the past century!), but most would place this in the beginning of the teenage years.
What a lot of people don’t know is that there another, earlier phase of puberty that everyone goes through, when hormones from the adrenal gland such as DHEA are released, that is aptly named adrenarche. Again, ages vary, but we think kids around 6-10 (maybe as early as 5!) are going through this development. There are some physical changes that go along with with this phase of puberty too, like an increase in body and pubic hair.
My colleagues and I are especially interested in this phase of puberty, partly because we know less about it than gonadarche, but also because there is some evidence to suggest that the timing of it (i.e., when kids go through this phase compared to their same sex and chronological aged peers) is associated with mental health problems. We also think that this might be due to important changes in brain development during this time of life, but we need more research to test this. The bottom line is that we need to better understand this phase of life for kids because it could have really important implications for their brain and mental health later in life.
We’ve written a review paper that systematically goes through all the literature on adrenarche, mental health, and brain development. Then we propose a model for future research to test if adrenarche is a particularly sensitive time of neurobiological and mental health development for kids. It’s just been published in the excellent journal* Developmental Cognitive Neuroscience. It is an open access journal, meaning that anyone can see the full text (BIG CHEERS FOR THAT!). I hope you enjoy reading it.
*Also be on the lookout for a special issue in DCN coming out later this year, on methodological challenges in developmental neuroimaging, that I am helping to guest edit.