Insanitize

[Dianne]

To essentially wipe the mind of all sane thought (and likely replacing with insane thought, though not necessarily so), presumably from [an encounter] with something so incredibly insane as to have the power to do so.
This process is similar to [sanitizing], but instead of removing dirt and/or germs, it removes rationale; thus, insanitize is an effective portmanteau of the words insane and [sanitize].