Bipolar Disorder or Manic Depression
A person with manic depression is in an abnormally elevated, persistently euphoric mood. The person is irritable argumentative and stubborn. The person has delusions of grandeur. They are like insomniacs,have a need to talk incessantly and are extremely restless.There is hypersexuality, weight loss and impulsiveness. Psychotic behavior is present during episodes. It can strike at any age. Most people are fully functional between episodes.

Major Depression
In this illness which is striking more and more people in modern society the person becomes depressed and loses interest and happiness in all activities .They cannot be cheered up. They become depressed , sad and have low levels of energy.They sleep too much, andhave increased thoughts of suicide. There is extreme fatigue and lack of energy.The pesron dwells on failures and has gulit feelings. They also blame themselves. They have no desire to interact or socialise. There is decreased sexual activity and lack of interest.