The range of course and outcome

Emil Kraepelin (1896) was the first psychiatrist to distinguish between manic-depressive psychosis and what he called dementia praecox, now termed schizophrenia. He made this distinction largely on the basis of their different courses, with manic-depressive illness having a relatively benign outcome and dementia praecox, as the name suggests, entailing progressive deterioration. This formulation has continued to have its adherents, holding the view that a psychosis that resolves cannot be called schizophrenia. Thus, the fourth edition of the Diagnostic and Statistical Manual of Mental Disorders (DSM-IV) of the American Psychiatric Association (1994) stipulates that schizophrenia can be diagnosed only if the symptoms have persisted for at least six months. A condition with exactly the same symptoms as schizophrenia but lasting less than six months is designated schizophreniform psychosis. Earlier diagnostic systems coined a variety of terms for short-lived illnesses with schizophrenic symptoms, including reactive psychosis, psychogenic psychosis, brief transient psychosis, schizo-affective illness, and the French term ‘bouffee delirante’. Guinness (1992) conducted a follow-up study of these transient psychoses in Swaziland and found that some patients relapsed with the same type of transient condition, while between 10% and 20% developed long-standing illnesses that satisfied DSM-IV criteria for schizophrenia. There was nothing in the clinical presentation of the first episode that distinguished between patients with these disparate courses.

Although transient psychotic disorders are less common in developed countries than in developing countries, they do occur.