Therapist

The Sim Shrink is an NPC that comes to your Sims when they go into aspirational failure (Aspiration bar in total red). He examines the Sims and helps them getting back a little of their Aspiration Bar, then he disappears again.

The shrink can only be seen by the sim that he is taking care off.

Using cheats, you can add the Sim Shrink to your family, but he will float away after a while, and be permanently stuck in your family.