The semester is coming to a close, which means a lot of late nights for some. However, there are many bad effects of sleep deprivation that people don't know about or choose to ignore. It has been proven that cramming doesn't help one study effectively, but many don't think about the toll on their body as well as their grades. Here are 11 reasons not to pull an all-nighter.

1. Sleep deprivation contributes to the symptoms of depression.

Sleep disorders and depression are very closely related. Not sleeping enough can worsen the symptoms of depression, while getting enough sleep can actually improve depressive attitudes.

2. Being sleepy makes you forgetful.

Have you ever noticed that when you don't get enough sleep, assignments and meetings seem to slip through your fingers? Sleep deprivation hinders your ability to make long and short-term memories and makes you more forgetful.

3. Losing sleep can make you gain weight.

Lack of sleep lowers your levels of hormones that signal when you are full. It also increases stress hormones which can cause you to eat more. This can cause substantial weight gain and is a contributor to obesity.

4. Sleep loss makes it hard to concentrate.

5. Sleepiness can cause accidents.

Lack of sleep slows your reaction times and can be very dangerous when driving. Sleepy driving is almost like driving drunk.

6. Lack of sleep makes it harder to learn new things.

7. Sleep deprivation weakens your immune system.

Your body creates antibodies while you're asleep. If you don't sleep enough then you don't have the right defenses against disease. It also makes it take longer to recover from an illness.

8. Sleep loss makes you clumsy.

Sleep deprivation hinders your fine motor skills, making you more clumsy and likely to injure yourself.

9. Sleepiness can make you more emotional.

10. Being sleepy stifles creativity.

Sleepiness makes it difficult to come up with new ideas as your brain is focused on trying to survive on three hours of sleep. Maybe save your poetry project for when you're all rested up.

11. Lack of sleep gets in the way of decision-making.

Lack of sleep increases activity in the part of the brain that sees good outcomes and less in the part that sees bad outcomes. This can lead to an overly optimistic view of potential decision.