Sleep deprivation can be defined as not obtaining an adequate amount of sleep. When someone is sleep deprived, they may notice changes in their health, specifically changes in the brain and cognitive functions. Sleep is a necessary, human function. Sleeping is an important human function because it allows our brains to recharge and our bodies to rest. Many people, especially high school and college students, do not realize the effects that sleep deprivation can have on their mental health; and how sleep deprivation can cause dramatic, possibly serious changes to their normal brain functions. While many do not realize the negative effects sleep deprivation can have on mental health, there is a link between sleep deprivation and mental health because it can put you at a greater risk of developing depression, can negatively impact mood, and can intensify levels of stress. One way sleep deprivation can affect mental health is by putting you at a greater risk of developing depression. According to the American Psychiatric Association, depression can be defined as a common and serious medical illness that negatively affects the way you think and feel. (Parekh) Depression can cause feelings of sadness, and can also cause you to lose interest in activities you generally enjoy taking part in. While depression is treatable, it is important to understand that sleeping well can help reduce and prevent symptoms of depression. In a 2013 study done by Maren Nyer; Nyer conducted an experiment on college students to study depressive symptoms in students with sleep deprivation and students without sleep deprivation. In this study, Nyer was able to conclude that “College students with depressive symptoms with SD (sleep deprivation) may experience a greater burden of comorbid anxiety symptoms and hyperarousal, and may have impairments in functioning, compared to students with depressive symptoms without SD”. (Nyer et. al) Another researcher, Matthew Walker, who conducted a similar study, suggests that “sleep deprivation functions similarly to depression and post-traumatic stress disorder” (Walker), also referred to as PTSD. Finally, sleep deprivation can also increase cortisol levels, an increase in cortisol levels can cause severe weakness, fatigue, and depression; which are all common symptoms associated with depression. A study that investigated cortisol levels found that in one hundred forty-five servicemen in China who were sleep deprived for a full twenty-four hours found that sleep deprivation could significantly increase cortisol level and may affect mental health in servicemen. The increase of cortisol levels is significantly related to mania disorder during sleep deprivation (Song). All researchers were able to establish a solid link between sleep deprivation and depressive symptoms. Another way sleep deprivation can affect mental health is by altering a person’s mood negatively. Mood is defined as a temporary state of mind or feeling. Often, when people are sleep deprived they may notice that they’re more overwhelmed, irritable, hostile, and angrier than usual. “People who suffer from sleep loss are especially likely to react negatively when something doesn’t go well for them”, says Amie Gordon of Psychology Today. That is because sleep deprivation enhances negative mood due to increase in amygdala activity, which functions with negative emotions such as rage and anger. In a study done by a group of University of Pennsylvania researchers, the researchers found that subjects who were limited to only 4.5 hours of sleep a night for one week reported feeling more stressed, angry, sad, and mentally exhausted. When the subjects resumed normal sleep, they reported a dramatic improvement in mood. (Dinges et al.) Chronic insomnia may also increase an individual’s risk of developing a mood disorder, such as depression or anxiety. Finally, sleep deprivation can affect mental health by increasing stress levels. Many, if not everyone has experienced some sort of stress in their life. Whether it be because of a new job, school, or stressful situations, stress is an uncomfortable emotional situation accompanied by predictable biochemical, behavioral, and psychological changes. Many studies have shown that stress increases when the length or quality of sleep decreases. When a person is sleep deprived, stress hormones tend to increase the following morning after a bad night sleep. A study of insomniacs published in the Journal of Clinical Endocrinology & Metabolism found that those with the worst sleep produced especially large amounts of ACTH (Adrenocorticotropic Hormone) and stress hormones throughout the day and night. In conclusion, many sources are able to conclude that there are negative effects of sleep deprivation on a person’s overall mental health. Sleep deprivation can negatively alter your mental health by making you more susceptible to depression as well as other mood disorders. When one does not receive the adequate amount of sleep to live a normal healthy life, many changes can occur. These changes can potentially be life-threatening if ignored over a long period of time. Because of this, it’s important to always remember the importance of sleep and the negative impacts it can have on you if deprived of it too.