There was also some work on repurposing fasoracetam for individuals with glutamate receptor issues, though I think they started with teens instead of adults. [0]

For a 2019 review of novel molecules, see [1].

[0]: https://www.nature.com/articles/s41467-017-02244-2 [1]: https://doi.org/10.1080/14737175.2019.1628640