Chapter 2

How psychedelics and ketamine work in the brain


What researchers think is happening, from receptors to brain networks, and what's still unknown.

In progressLast updated September 26, 2026

This chapter is being written. Every chapter is reviewed against the published research before it goes live.

What this chapter will cover

  • Serotonin 2A receptors and classic psychedelics
  • NMDA receptors, glutamate and ketamine
  • Neuroplasticity and the ‘window’ after treatment
  • Brain networks and the default mode network
  • What we still don’t know