A study that involved more than 1.1 million people from 20-102 years old, by doctors at the University of San Diego and the American Cancer Society, indicated that the best survival rates were found among people who slept seven hours per night. Those who slept eight hours or more, and those who slept less than six hours per night, significantly increased their mortality risk. An increased risk of more than15% prevailed among those who slept more than eight and one-half hours, and those who slept less than three and one-half to four and one-half hours per night. People who complained vaguely of insomnia did not increase their risk. According to the study, prescription sleeping pill use was associated with significantly increased mortality after control for reported sleep durations and insomnia.

A prevalent idea is that everyone needs a solid eight hours of sleep every night, but many people do not realize that six to seven hours is the population average. Another study reported that people who slept longer than eight hours reported they had less energy and more psychopathology. Short sleepers did not report this. Insomnia and short sleep are not synonymous. People whose sleep durations fall well within the range of people without sleep symptoms often complain of insomnia. Misinformation about what sleep patterns are normal for a patient’s age may give rise to such complaints.

Sometimes when presented with a patient who is complaining about their quantity or quality of sleep, physicians are inclined to diagnose depression rather than insomnia.

It appears that sleeping too much or too little has a greater effect on men than on women. One study of 1,741 people found that men who slept less than six hours per night were at 19.6% increased risk for mortality. For women, the rate was 10.3%. Female patients were followed for 10 years, men for 14 years. In this study, insomnia was defined by a complaint of insomnia with duration of greater than a year, while poor sleep was defined as a complaint of difficulty falling asleep, staying asleep or early final awakening. Polysomnographic sleep duration was classified into two categories; people who slept greater than six hours, and those who slept for less than six hours.

Insomnia is associated with medical morbidity and mortality rates similar to those seen in patients who suffer from obstructive sleep apnea, according to the study’s lead author, Alexandros Vgontzas. Cognitive behavior therapy (CBT) he went on to say, may be of use in extending sleep duration and reducing the risk of mortality. And that’s not all. In another study led by the same author, it was found that measured short sleep duration is associated with increased risk of diabetes. Even though they have normal sleep duration, patients with insomnia are at increased risk for depression and the behavioral effects of insomnia.