Here is an outstanding essay explaining ketamine treatment for depression: The current mental health crisis and the coming Ketamine revolution
The author is a PhD neuroscientist with a deep understanding of the science and the issues. Instead of rehashing the same oversimplified messages like most articles about ketamine, this one gives a complete explanation of the key issues, and makes them very easy to understand without dumbing anything down. Most articles about ketamine recycle the same soundbites, using the same oversimplified headlines. But this article gives a complete overview, and explains how ketamine fits into the bigger picture of the US mental health care system. It contrasts ketamine against the established approach toward treating depression, which has essentially failed those with severe, treatment-resistant depression. Highly recommended reading.
The author, Dr. Pascal Wallisch, has a blog (pensees.pascallisch.net) and twitter feed (https://twitter.com/Pascallisch) that cover topics in neuroscience and psychology. Many of his posts are very relevant to depression sufferers.