Recs for fiction with strong psychological overtones, please - not necessarily psycho to the point of madness (although always interesting) - and definitely not limited to the free-flowing angst that is sometimes Dean's (or teen-Sam's) internal, self-centered monologue.

Please rec (or self-rec) stories where the psychology of a character (or characters) is particularly effective, as a means of advancing the plot or illuminating the character in a new way. Yes, I realize that many fics have psychological issues as subtext, but I'd like to hear your takes on those stories that elevate it to a feature of the main plot/character - in a twisty or otherwise interesting way. (e.g., sandymg's wonderful One Small Step, in which Jared's Aspergers often drives the plot and the relationship)

NOTE:I chose a few tags from the 'Affliction' and 'Genre' categories as examples, but we're not limited to these. Also, no matter if story is gen or slash.

As always, thanks to the community for your inexhaustible expertise.