On a basic neurochemical basis, it is an N-methyl D-aspartate (NMDA) receptor inhibitor.
Blocking the NMDA receptor allows for modulation of glutamate (an excitatory neurotransmitter) and ultimately increases levels of Brain-derived neurotrophic factor (BDNF) and mammalian target of rapamycin (m-TOR), which create protein synthesis in neurons.

Many ketamine experts consider this process a “reset” button for the brain, just like you would reset your computer. A ketamine infusion allows the unhealthy neuronal pathways that are constantly “on” in your brain to turn off for a period of time.
One can consider all the unhealthy thoughts that continuously occur – such as automatic negative thoughts, obsessive thoughts, anxious thoughts, persistent pain – as these unhealthy pathways. When your brain comes back “on-line”, you can then access the more healthy pathways or loops in your brain.

Simply put, ketamine works by shutting down overactive neurons while improving the healthy function of the existing neurons. In addition, ketamine improves neural connectivity in the brain that enhances daily, healthy brain function. Ketamine helps a patient restore executive control of their thoughts and emotions.