After several weeks of feeling apathetic, sad and dissatisfied with his life, Chris has suddenly become extremely cheerful and so talkative he can't be interrupted. He seems to need little sleep and becomes irritated when his friends tell him to slow down. Chri's behavior is indicative of .

Bipolar Disorder.

Explanation:

This is a mental disorder formally known as maniac depression which comes with different forms of dramatic mood swings which ranges from low to high. According to research, it is said to be caused by hormonal disorder or imbalance in a human body. This could give the said person(s) suicidal thoughts too in the cause of these steady depressions. Treatment of bipolar disorder cannot be pointed out exactly ad it last for weeks and months.