It is generally assumed that a good night's sleep has a beneficial effect on mood. The present survey aimed to evaluate what a good night's sleep means for mental well-being and psychic functional capacity. A random community sample of 670 adult subjects was divided into three groups: good, intermediate and poor sleepers according to a sleep habit questionnaire based on self-reports. Their cognitive, emotional and personality features were assessed with various psychometric and personality tests, and differences between the groups were evaluated statistically. In the age- and gender-adjusted population the average good sleeper turned out to be a person who falls asleep in 10 minutes, after which his/her 7.5 hours' sleep is serene and without parasomnias. Immediately on awakening in the morning and later during the day he/she is mentally alert without distress or emotional problems.
Definite mood and personality differences between good and other sleepers in the adult population surveyed revealed that good sleepers are psychologically capable of maintaining a self-esteem which is in functional balance with their life-goals and mental well-being.