Temporal narcosis

Temporal narcosis is a condition whereby one experiences overwhelming neurophysical stress when entering another time continuum, in much the same way deep sea divers experience nitrogen narcosis.

In 2369, Captain Jean-Luc Picard experienced temporal narcosis shortly after boarding the USS Enterprise (NCC-1701-D), which had become trapped in a temporal fragment. Succumbing to this condition, Picard alternately experienced states of hysteria and panic, before being beamed out of the fragment's influence.