Yes, you CAN get too much.
Ah, sleep. The ever-elusive natural health elixir that can squash a shockingly vast variety of our physical and mental ailments. Regularly getting a good night’s rest can boost your mood, sharpen your memory, and stave off anxiety, depression, and stress. It also helps you control your weight, increases your body’s immunity, and lowers your risk of heart disease, diabetes, stroke, and various types of cancers. We can go on if you want: Sleep also pumps up your libido, clears your skin, stimulates your creativity, and makes you less likely to get into car crashes, while not sleeping enough can literally make people not want to be around you and physically shrinks your brain.  […]

Source: This Is The ‘Sweet Spot’ For How Long You Should Be Sleeping