There are similarities in the general quality of the mental state. The BIG difference is that ketamine is dissociative. Perceptions on LSD and shrooms are still

There are similarities in the general quality of the mental state. The BIG difference is that ketamine is dissociative. Perceptions on LSD and shrooms are still strongly correlated with real sensory input. You're hyperconscious of your real surroundings. Ketamine is more like a lucid dream where you're having a rich, strange experience, but not very conscious of your real surroundings.