The history of bipolar disorder changed with Emil Kraepelin, a German psychiatrist who broke away from Sigmund Freud’s theory that society and the suppression of desires played a large role in mental illness. biological Kraepelin recognized causes of mental illnesses. He is believed to be the first person to seriously study mental illnesses.
Kraepelin’s Manic Depressive Insanity and Paranoia in 1921 detailed the difference between manic-depressive and praecox, which is now known as schizophrenia. His classification of mental disorders remains the basis used by professional associations today.