The Mood Rollercoaster
 

People who experience polar opposites from elation or agitation to despair
are said to have bipolar mood disorders. This term includes any significant
up-and-down cycles in moods and makes it easier to recognize the problem
before it reaches the incapacitating stages that warranted a (now out-of-
date) diagnosis of manic-depressive illness. Low periods are often
confused with “unipolar” disorders of major depression, recurrent
depression, and dysthymia (low energy, pessimism, and withdrawal).
Medication that treats one disorder may not be effective for the other. The
table below can help distinguish these two branches of the same
biochemical tree.

   Unipolar Mood Disorders                Bipolar Mood Disorders

DETECTING BIPOLAR DISORDER AND ITS COUSINS

The best way of identifying a bipolar disorder is by careful observation of
mood over time. The 0–100 scale on the Mood Chart is offered for that
purpose. It can also be used to classify several varieties of mood disorders:

• Normal mood: Moods vary from 40 to 60 except for periods of
  grieving a loss.

• Cyclothymia: Mood cycles from 30 to 70 over a period of hours or
  days.

• Dysthymia: Mood has been in the range of 30 to 45 for over a two-
  year period.

• Hypomania: Mood stays in the 55 to 70 range most of the time but
  can have manic episodes.

• Bipolar II disorder: Mood is most often in the 30s or 40s, with periods
  of relief in the 60s.

• Bipolar disorder: Mood can swing from the 30s or below to the 70s or
  above.

• Major and reoccurring depression: Mood is below 40 for two or more
  weeks.

Reference

See A Mood Apart by Peter Whybrow (Harper Perennial, 1997, p. 113).
Other research shows a 0–13% chance of both fraternal twins having
depression, suggesting a strong genetic link in unipolar depression.