Bipolar disorder is a common mood disorder. To answer your question, Bipolar disorder is the more common term, but manic depressive is a term that refers to the same condition. This diagnosis requires significant attention and follow up with your
doctor. You may benefit from having a trained
psychiatrist (or mental health specialist) who can help with medicines and therapy for this disorder.
Bipolar disorder is a mood disorder in which patients experience two different types of episodes. One type of episode that they experience is known as a manic episode -- in which they feel high, are very distractable, have increased energy, have fast thoughts, have grandiose thoughts and often are very active / ambitious / reckless. The other type of episode is a depressive episode -- in which people are often tired, depressed, slowed down and fatigued. These episodes can last between weeks and months and people with bipolar can be in either a normal / balanced state, or in one of these episodes. Because the manic episode appears the exact opposite of the depressive episode, the disorder is known as bipolar. Others call this manic depressive as people are alternatively manic and depressive. Rarely, people have a mixed episode with features of both.
Talk to your doctor. This requires significant follow up.