There is a direct relationship between the amount of time you spend sleeping and your efficiency. It turns out that decreasing sleep by as little as 1.5 hours for just one night reduces daytime alertness by 32 percent. In addition, people who get less than six hours of sleep per night have a 70 percent higher mortality rate than those who get seven or eight hours a night. Given these statistics, it's not surprising that a study at UCLA concluded that sleep's primary function is to "increase efficiency and minimize risk by regulating the duration and timing of behavior."

Humans spend about one-third of their lives sleeping, but it's surprising that many executives still do not allow themselves to get enough sleep, insisting that they need to burn the proverbial midnight oil to keep up with their workload. Unfortunately, what occurs is counter-productivity - the exact opposite of the intended result.

It's no surprise that sleep improves memory and learning, but most individuals who do not get enough sleep are unable to recognize the effects of their lack of sleep on their mental health. And lack of sleep can be dangerous - some statistics show that almost 20 percent of US traffic accidents occur due to driver fatigue. Chronic fatigue along with a myriad of other symptoms, are caused by lack of sleep. Here are a few other areas affected by lack of sleep that ultimately contribute to poor efficiency both on the job and at home.

1. Thinking. Lack of sleep leads to reduced capacity of attention and concentration. This may lead to difficulties in making decisions or making the wrong decisions.
2. Memory. Nerve connections needed in memory are able to recover and harden during sleep. If you don't get enough sleep, you are more likely to forget things. Sleep is necessary to enable the storage of experiences and knowledge into short-term memory. If you're not sleeping enough, you're not remembering enough.
3. Difficulty learning new things. Lack of sleep makes learning more difficult because of an inability to focus. This leads to impaired memory. Studies have also shown that lack of sleep can contribute to hyperactivity in children.
4. Mood. If you're irritable, angry, or unable to handle normal stresses of the day, lack of sleep may be to blame.
5. Low energy. Lack of sleep creates less energy to do more of the healthy things in life such as exercising and eating a well-balanced diet.
6. Depression. Fatigue caused from lack of sleep increases the risk of depression. A University of North Texas study found that people with insomnia are ten percent more likely to develop depression and 17 times more likely to have anxiety.

So how do you know if you're getting enough sleep? The best indicator is when you awake in the morning and you don't feel sleepy. You should be energetic throughout the day and feel more tired as the day progresses. If this doesn't describe you, then you're not getting enough sleep.