ABSTRACT
Few psychiatric conditions occur as frequently as affective disorders. Not only are they relatively common disturbances, but depression and mania are also associated with a range of syndromes of varying types and intensities. The presence of psychotic symptoms in some patients suffering from manic or depressive disorders, or both, has long been observed; however, it was not until the last 35 years that researchers have begun to study the nature of thought processes in these patients.
