Bipolar disorder is theorized to be an evolutionary adaptation to colder climates, therefore it should come as no surprised that this illness has a recorded history going back 2000 years. It used to be that everyone who wasn't normal was just called crazy or they may have been considered to be possessed by evil spirits, as mental illnesses weren't well understood long ago.
The words "depression" and "mania" have their origins in Ancient Greek, and by 100 AD Ephesus, a Greek historian, described depression and mania linked into one disease. It was not until 1025 that Avicenna, who was a Persian physician, identified a number of mental disorders, such as schizophrenia, bipolar, and mania.
With the stigma of mental disorder, any research into this illness largely went unnoticed. After all, most individuals didn't want to be classified as mentally insane, and most would have considered mental illnesses to be a flaw in moral character.
For this reason, biphasic mental illness was not rediscovered until 1854, by the French doctor Jules Baillarger, who described the differences between mania and depression, and how they shifted in persons with the illness.
Emil Kraepelin was a German psychiatrist and the first to term the illness "manic depressive psychosis." He observed patients with periods of extreme depression and mania, intermixed with periods that were symptom free.
It was not until 1948 that a treatment plan was devised for bipolar disorder. Lithium carbonate was developed by Dr. John Cade of Melbourne, Australia, offering hope to those suffering from a disease that had been stigmatized for thousands of years.