I recall reading a long time ago, a Spuffy written by someone, who claimed to be a therapist, specializing in depression.

In their story, Spike, Dawn, Tara and, maybe Anya were helping Buffy out with some exercises and therapy techniques to help treat her depression, from the trauma of Willow's botched resurrection.

It might be possible, the writer was a depression patient and she used the exercises she actually used in her own recovery, in her own Spuffy fic.