The developing brain

Transgender Trend summarizes some of what is known about puberty blockers and brain development:

When a child’s natural puberty is blocked we can expect to see effects not only on the body but on the developing brain. It is the surge of sex hormones at puberty which triggers the important changes in the adolescent brain which only reach completion in the mid-twenties. Hormonal changes at puberty  are thought to influence the development of both brain structure and function.

Recent research indicates that there is a window of development for some cognitive functions, and if this window is missed, cognitive development does not resume later even if blockers are discontinued. A reduction in long-term spatial memory was found to persist after discontinuation of blockers in a recent study on sheep, which concluded:

This result suggests that the time at which puberty normally occurs may represent a critical period of hippocampal plasticity. Perturbing normal hippocampal formation in this peripubertal period may also have long lasting effects on other brain areas and aspects of cognitive function. 

You’ll notice the wording is far from absolutist. The result suggests, the time may represent, perturbing normal formation may have lasting effects. This isn’t the usual Guardian-style manipulation, this is normal caution with new and sparse research.

Two previous studies which analysed IQ performance in girls taking puberty blockers for central precocious puberty also suggest the possibility that GnRHa treatment may have an adverse impact on cognitive functioning in children. The first study of 25 children in 2001 found a drop of 7 IQ points after two years on blockers. The second study in 2016 found a drop of 8 IQ points in 15 girls compared to a matched control group. An analysis of these studies is here.

Oy. On the other hand is there a control group? Maybe everybody sheds IQ points during puberty?

A study in 2017 of men with late stage prostate cancer found that treatment with GnRH analogs affects cognitive functions such as language ability, short-term memory capacity, mental flexibility, and inhibitory control.

Oy. Not functions you want to reduce. Also – could help explain the childish unreasonable bad-tempered nature of the “activism.”

At any rate, the issue needs more attention, if you ask me.

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