Almost 2% of all US citizens will experience Bipolar Disorder. This is a disorder which both has depression and manic features. A patient will experience intermittent episodes of depression and mania/hypomania. Between episodes a person will often feel normal and there will not be anything to notice.
Depression
In almost all cases this disorder will first start with an episode of depression. That is why so many patients are diagnosed with primary depression instead of bipolar disorder because it will only become bipolar when a patient will experience manic episodes in the future. When experiencing depression, a person will feel really sad and he will believe that his situation is hopeless. It is not just a matter about feeling a little bit sad for a while, but it is feeling sad for at least 3 months which prevents normal functioning in society.
Mania and Hypomania
Bipolar depression is a mood disorder and both extremes are out of balance. In an episode of depression a person will feel really sad and depressed, but in an episode if mania a person will feel extremely good. He will feel he can take on the entire world and will succeed in all that he undertakes. Although this may sound great, a person can get himself in dangerous situations and do harm to himself. He will also not care about his finances and shop for everything that he likes and wants.
Hypomania
But a person will not always feel extremely well about himself, in some cases he will feel extremely annoyed about everything. Instead of feeling great he will feel annoyed about small thing and might even react aggressively. He could shout or hit someone in an act he would otherwise not do.
Psychotic features
In some cases a manic or hypomanic episode can become a psychosis. When this happens a person will lose all contact with the real world and will live in a world of his own. He might experience hallucinations and see people walking that are not really there. Psychotic patients often experience anxiety because they feel they are endangered. The only way to reduce these symptoms is by giving medication. When a person experiences psychotic episodes it is called manic depressive disorder with psychotic features.