Professor James Potash explains that bipolar disorder is episodic: people get ill, then they get well again and then the illness may come back again at a later date.
Bipolar Disorder is an illness that was once referred to as manic depressive illness, and those two things are more or less the same. Bipolar refers to the two different poles of mood, the high pole and the low pole; the low pole being depression, and the high pole being at its extreme mania, and then a milder version of that is called hypomania. If you have mania you have bipolar type I disorder, and if you have hypomania you have bipolar type II disorder. Bipolar disorder differs from schizophrenia in that typically it’s what we refer to as an episodic illness; meaning that people get ill, then they get well again and then the illness may come back again at a later date. Typically with schizophrenia you have the onset of illness and you never really get back to being yourself again.