At the SLEEP 2009 conference in Seattle this week, researchers from the University of California – Berkeley revealed results of a study that showed naps with rapid eye movement sleep refresh the brain’s perception of positive emotions. Study participants who took a 60 to 90 minute nap mid-day with REM sleep were much more receptive to happy facial expressions. Those who didn’t nap had an increased reaction to negative emotions.
Most opiate users never nap and during the night they do not experience good REM sleep. This may be another factor contributing to the sadness and depression that opiate dependent people experience.