A new study published in the journal Nature Neuroscience suggests that a good sleep can help calm some fears.

On showing both the faces when they woke up, the researchers found that their fear reactions to the face that was linked with the odor that they had been exposed to when sleeping was slower compared to the other face.
“Sleep sort of stamps memories in more strongly. That’s when a lot of memory formation can take place. From a clinical perspective, this can be a new approach to try and treat stressful or traumatic memories”, lead researcher Jay Gottfried said.
Source-Medindia