The Therapy Mod allows you to assign skilled colonists to perform therapy on others. Distressed colonists will lie on the couch in their free time and available therapists will come to counsel them.
Going into therapy will make bad memories go away faster than usual. Might even remove addictions and other effects in future updates of this mod.
Therapy Mod instructions
To begin a therapy session you simply need to build a couch and a chair close by, and it will become a therapy room. Make sure you have at least one colonist set to perform the therapy job.