tokens: ) In 1920 , psychiatrist Emil Kraepelin ( 18561926 ) , the founder of contemporary scientific psychiatry , observed a " great number " of cases that had characteristics of both groups of psychoses that he originally posited were two distinct and separate illnesses , " dementia praecox " ( now called schizophrenia ) and " manic depressive insanity " ( now called bipolar disorders [ plural since there are more than one type of bipolar disorder ] and recurrent depression ) .