Mood is difficult to define. However it can be thought of as the character of feeling that someone is going through and can range from feeling sad or depressed to feeling happy or elated. At present there is a general acceptance that when feelings are experienced at their extremes, either sadness or happiness they will affect how someone functions. One can thing of this disturbance as the marker of disorder. There is a reasonable argument hear that if the feelings are not affecting how someone functions both in their own life and in society, strictly speaking this is not a disorder.
Two types of extremes of mood or feelings that are a mood disorder are recognised to be on the one hand Depression and on the other extreme opposite end Mania.
Plum- Doctors refer to people who experience only Depression as having a Unipolar Disorder.
Some people during their lives only experience Depression. In addition other people never experience the extreme of mania but in addition to Depression they have episodes were their mood is higher than normal and they themselves feel this way as well as other people do notice. This elevation or heightening of mood is not extreme to be called mania and so it is referred to as hypomania (lower than mania).
Because these individuals experience both Depression which is low mood and Mania or Hypomania which is elevated mood they are said to have Bipolar Disorder. Think of this as someone experiencing two poles of mood. At one point low and at another point high.
So as opposed to Unipolar Disorder, Bipolar disorder people will have at a point in time low mood in other words Depression and at another point the other side which is elevated mood. This elevated mood can be as intense as mania or less intense but still high referred to as hypomania.
Plum- Therefore, Bipolar Mood Disorder is divided mainly into two subtypes. Bipolar type 1 and Bipolar type 2.
Here it gets slightly confusing but not that difficult to understand in all truth!
Bipolar Type 1- People who are at the extreme high of mood may be thought of as having Mania. If you experience Mania with no episodes of Depression you are still considered to have Bipolar type 1. Interestingly if you also have experienced Depression in the past you are still considered to have Bipolar type 1
Plum- Mania with or without Depression is Bipolar Type 1
People who experience Depression and Hypomania are said to have Bipolar 2. In otherwords you have to have Depression at some point then hypomania.
Plum- Depression plus Hypomania is Bipolar 2