First, it is important to understand that insomnia and sleep deprivation are two entirely different sleep problems. Those who have insomnia have the opportunity to sleep uninterrupted, but cannot take advantage of the opportunity; while those who suffer from sleep deprivation aren't afforded the opportunity for uninterrupted sleep. They are two different problems, but the effects are basically the same -- the lack of proper rest and the resulting lack of concentration and performance.

Those who suffer from only an occasional bout of insomnia will quickly recover from it. The normal insomnia will last for one night or possibly two and then the sufferer will sleep like the proverbial log on the next night. Those who suffer from insomnia are not inclined to nap during the day. They have the opportunity to sleep at night, and if sleep doesn't find them, it will be the next night before they have another opportunity.

Those who suffer from sleep deprivation are usually good sleepers who are put into a position where their normal sleep patterns are disrupted. Parents of a newborn baby, for example, may suffer from sleep deprivation. Shift workers also suffer from sleep deprivation. Their normal sleep pattern is disrupted by their having to work at night and only having an opportunity to sleep during daylight hours. Their internal clocks don't let them sleep during daylight hours, but they aren't suffering from insomnia. In the case of sleep deprivation, most of those who suffer from it immediately return to normal sleep patterns once the situation allows them to.

Insomniacs, however, have a much more difficult time with reestablishing normal sleep patterns once they fall victim to a prolonged battle with insomnia, and most of the time medical intervention is required.