Magnesium has an important role in the chemistry and development of neurons, *an...

Magnesium has an important role in the chemistry and development of neurons, and it is very common for people to have a shortage of it:

https://pubmed.ncbi.nlm.nih.gov/31336935/

In my case taking magnesium helps with insomnia and ADHD symptoms (although it's impossible to tell if the ADHD improved directly due the magnesium, or due to better sleep)