Apparently, happy memories are a lot stronger than sad feelings, according to a new study (in mice).
Researchers from the RIKEN-MIT Center for Neural Circuit Genetics found that recalling positive memories might be able to reverse stress-induced depression.
The team used genetic engineering to create mice in which memory cells could be tagged while memories formed and later reactivated. Basically, they could force the mice to recall a past experience.
Here's what they found, from the press release: