I think this is the fic you're talking about. The Crystal Ship (http://8-track-gems.livejournal.com/16790.html) by autumn_lilacs
Other recs about insanity:
Blue Skies from Rain (http://lovesrain44.livejournal.com/26355.html) by lovesrain44 - The morning after Sam rescues Dean from the djinn, Sam and Dean go back to the warehouse to take care of the bodies of both the victims and of the djinn. But instead of what should be a simple clean-up job, Sam and Dean are sucked into a nightmare world brought about by the djinn’s last dying act of revenge. (Takes place directly after What Is and What Should Never Be.) What do you do when you wake up in a mental institution and you think your brother is dead? Sam/Dean
The Crow on the Cradle (http://kroki-refur.livejournal.com/72426.html) by Kroki Refur - On October 2, 2005, Sam Winchester walked out of the apartment he shared with his girlfriend Jess in the middle of the night, and didn't come back.
Sanity is Relative (http://www.fanfiction.net/s/6041618/1/Sanity-Is-Relative) by whinom - AU. Dean goes a little crazy after Sam goes to Hell.
The Storyteller (http://toldthestars.livejournal.com/17932.html) by toldthestars - Dean is an incurable schizophrenic and has been since childhood.
And I have some more mental illness recs here (https://sites.google.com/site/fanficthematic/home/cross-fandom/mental-illness#spn).
no subject
The Crystal Ship (http://8-track-gems.livejournal.com/16790.html) by autumn_lilacs
Other recs about insanity:
Blue Skies from Rain (http://lovesrain44.livejournal.com/26355.html) by lovesrain44
- The morning after Sam rescues Dean from the djinn, Sam and Dean go back to the warehouse to take care of the bodies of both the victims and of the djinn. But instead of what should be a simple clean-up job, Sam and Dean are sucked into a nightmare world brought about by the djinn’s last dying act of revenge. (Takes place directly after What Is and What Should Never Be.) What do you do when you wake up in a mental institution and you think your brother is dead? Sam/Dean
The Crow on the Cradle (http://kroki-refur.livejournal.com/72426.html) by Kroki Refur
- On October 2, 2005, Sam Winchester walked out of the apartment he shared with his girlfriend Jess in the middle of the night, and didn't come back.
Sanity is Relative (http://www.fanfiction.net/s/6041618/1/Sanity-Is-Relative) by whinom
- AU. Dean goes a little crazy after Sam goes to Hell.
The Storyteller (http://toldthestars.livejournal.com/17932.html) by toldthestars
- Dean is an incurable schizophrenic and has been since childhood.
And I have some more mental illness recs here (https://sites.google.com/site/fanficthematic/home/cross-fandom/mental-illness#spn).