Yes, this is the other competing theory - NMDA is linked to neural plasticity and another theory as to the action mechanism of SSRIs. If I recall one issue with

Yes, this is the other competing theory - NMDA is linked to neural plasticity and another theory as to the action mechanism of SSRIs. If I recall one issue with the Seratonin SSRIs theory is the time lag between the detectable seratonin between synapses and subjective effect. It's not accurate to say Ketemene (S-Ketemine) has no action on the Seratonin pathway, I believe there was a recent study that found a possible action via the 5-HT_1B receptor.