Schizophrenia is typically a catastrophic illness that begins in adolescence or early adulthood.
Although severe psychotic disorders have been recognized for centuries, as evidenced by descriptions in medical writings and literary portrayals, the classification of psychotic disorders into specific forms such as manic-depressive illness or schizophrenia only occurred approximately one hundred years ago. Schizophrenia was initially defined in the late nineteenth century by him and a team of psychiatrists who worked with him, which also included Alois Alzheimer. Schizophrenia is characterized by a mixture of signs and symptoms, no one of which is necessarily present. In this sense, it differs from many other psychiatric disorders, which are typically defined by a single prominent feature. Depression, for example, is characterized by dysphoric mood, mania by elevated mood, and panic disorder by the presence of panic attacks.