Graph of a Probability Distribution. A probability distribution can be graphed, and sometimes this helps to show us features of the distribution that were not apparent from just reading the list of probabilities. The random variable is plotted along the x-axis, and the corresponding probability is plotted along the y-axis.
Manic-depression: Alternating moods of abnormal highs (mania) and lows (depression). Called bipolar disorder because of the swings between these opposing poles in mood. A type of depressive disease. Not nearly as prevalent as other forms of depressive disorders. Sometimes the mood switches are dramatic and rapid, but most often they are gradual.
Bipolar I disorder is referred to as manic depression. Manic depression presents differently for each individual, but the diagnosis requires a history of at least one manic episode. A manic episode involves a period of time in which emotions are elevated in a positive direction, often for no particular reason. Brief elation at a piece of good news is not manic, but a few weeks of that feeling could indicate mania. Individuals with bipolar I often spiral into depression following episodes of mania.