> An interesting new drug is Auvelity, where Dextromethorphan is proposed to help stimulate neurotropic growth factor to help the brain repair itself,

Auvelity is interesting, but the exact mechanism of action is not very clear.

Auvelity is a combination of two drugs: Dextromethorphan and Bupropion. Bupropion, aka Wellbutrin, is an antidepressant by itself. In Auvelity it helps alter how Dextromethorphan is processed by the body, but we can't rule out that it contributes to the antidpressant effect. I mean it's literally an antidepressant.

Dextromethorphan has a lot of interactions and gets a lot of comparisons to ketamine because it has NMDA affinity, but if you look at the table of receptors it interacts with the serotonin receptor is one of the strongest interactions. It is a potent serotonin reuptake inhibitor, which is also known to have antidepressant effects. It also has some sigma receptor interactions which might be doing something significant.

The NMDA interactions get all of the attention because if you put "ketamine" in the headline you get a lot more attention, but NMDA may be much lower on the list or even negligible for this combo.