Dementia Praecox: A term coined by Kraepelin to describe what is now known as schizophrenia, characterized by a deterioration of mental functions at an early age.
Manic-Depressive Illness: A term used by Kraepelin to describe what is now known as bipolar disorder, characterized by alternating periods of mania and depression.
Diagnostic and Statistical Manual of Mental Disorders (DSM): The standard classification of mental disorders used by mental health professionals in the United States, which has its roots in Kraepelin's work on psychiatric nosology.