The following is a guest post from Allie.

While you toss and turn in bed, the numbers on the clock are inching slowly forward, creeping closer to the morning alarm. With each passing minute, your anxiety increases, making sleep even more elusive. You roll out of bed to start your day feeling groggy and disoriented. You are not alone. According to the American Psychological Association, 60 percent of adults report having trouble sleeping a few nights per week or more, and it doesn’t take a psychology degree to know that living a groggy life can’t be good for your mental fitness. Over 40 million Americans have a sleep disorder that affects their health.

The amount of sleep needed to function properly varies from person to person, but a study by the National Sleep Foundation found that most people need at least seven hours of sleep per night, though we average only six and a half. When a person doesn’t get enough sleep to suit their body’s needs, they create a sleep debt that is often times not satisfied. This leads to fatigue and an inability to function at an optimum level.

The brain haze that most people experience after a poor night’s sleep is not something that can be alleviated with a few lattes. In fact, an inadequate amount of sleep, even for just one night, has a substantial impact on your mental focus. One startling finding by the CDC has shown that “insufficient sleep is responsible for motor vehicle and machinery-related crashes, causing substantial injury and disability each year. In short, drowsy driving can be as dangerous — and preventable— as driving while intoxicated.” This is because sleep deprivation slows reaction time and impairs hand-eye coordination.

Not only does lack of sleep affect motor skills, it also diminishes concentration. The foggy feeling that comes with a sleepless night, is partially due to a decline in alertness and concentration. Without the capability to pay attention, an individual becomes confused and has difficulty with complex thought. The ability to learn and process information is also hindered because of this lack of concentration. Focusing on complicated tasks is challenging and sleepy individuals often have a difficult time blocking out distractions.

Inadequate sleep impacts decision making skills as well. The brain’s executive functioning ability deteriorates with sleeplessness. A study at Duke University in which subjects completed economic decision-making tasks after being deprived of sleep, concluded that sleep deprivation caused people to overestimate the likelihood of positive outcomes and underestimate the likelihood of negative outcomes. This lead to a distorted risk perception, inciting subjects to make risky, and usually poor, economic choices. One of the study’s co-authors likened the findings to the evidence that medical residents made more mistakes after long work hours. In occupations that require strong decision-making skills, overly risky behavior caused by sleep deprivation can lead to job loss, financial issues, and harm to employees, customers, or co-workers.

Memory also relies heavily on sleep. The nerve connections in the brain that make new memories are strengthened during sleep. When the sleep cycles are disrupted, the memory is impaired. Sleep is needed to process what you have learned during the day. Researchers at Harvard Medical School performed memorization tests on healthy subjects. After half of the subjects were deprived of sleep, they were shown 150 slides of various people and objects and told to memorize them. 24 hours later, even after catching up on sleep, the sleep deprived subjects still performed poorly when asked to recall which slides they had memorized the day before. Furthermore, this memory deficiency wreaks havoc on language skills. Not only do individuals often experience slow or slightly slurred speech, but finding the correct word becomes an arduous task.

In a fast-paced world, multi-tasking and creativity are often essential to productivity. Sleep deficiency decreases the ability the ability to multi-task and stifles creativity. These effects are likely related to the inability to the loss of mental focus associated with sleep deprivation. Producing new ideas or creative solutions can be seemingly impossible, as the portion of the brain responsible for creativity is affected. A recent study showed that the ability to attend to multiple tasks simultaneously, the flexibility to alter one’s focus, the ability to follow multi-step instructions, the use of complex reasoning, and the ability to employ creative problem solving skills were diminished by sleep deprivation.

Cognitive functions are not the only thing affected by sleep deprivation. According to the National Sleep Foundation, emotions also tend to go haywire. One of the first signs of sleep deprivation is irritability. If an individual does not sleep after the initial symptoms, it can lead to flattened emotional responses, apathy, anger, or depression. This in turn can lead to an increase in risk taking behaviors, such as drug and alcohol abuse, and further impairment of cognitive abilities.

While research indicates that sleep deprivation leads to a deterioration in mental fitness, a select few claim to thrive on an inadequate amount of sleep. An MSN news article discussed “creative insomnia” and cited the theory that sleeplessness leads to an altered state of consciousness. Mild insomnia can help a minority of artists disassociate from reality and at times this can produce works of genius. Severe insomnia often results in hallucinations, which some argue brings out dream imagery. However, even those that hold this theory to be true, admit that the majority of people are more creative after a satisfying night’s sleep.

An overwhelming amount of research suggests that sleep deprivation is not only harmful to individuals’ health, but also has a considerable impact on mental fitness. National Geographic reported that sleeplessness in the United States has accounted for an estimated 50 billion dollars in lost productivity. Yet, it’s the personal costs that cause the most harm. Whether you are a shift worker, new parent, student, or insomniac, finding a way to get adequate sleep is integral to your quality of life.