LATE-ONSET SCHIZOPHRENIA AND LATE PARAPHRENIA

The term ''late-onset schizophrenia'' was first coined by Manfred Bleu ler (1943) to describe a form of schizophrenia with an onset between t he ages of 40 and 60. This concept has been adopted by German psychiat ry. Until recently, British and American psychiatrists had little inte rest in this patient group. However, they often used the term ''late-o nset schizophrenia'' interchangeably with late paraphrenia or as a gen eric term for both these diseases, even though the concept of late par aphrenia is quite different from that of late-onset schizophrenia. Lat e paraphrenia is a British concept that includes all delusional disord ers starting after age 60. This confusion of terms and concepts is eve n more important now, because recent neuroimaging and neuropsychologic al studies suggest that an organic substrate probably exists in most c ases of late paraphrenia, while only minor organic abnormalities can b e found in late-onset schizophrenia. We believe it is of utmost import ance to establish a clear boundary between late-onset schizophrenia an d other delusional disorders in middle and old age, because the confus ion in terminology and concepts is a serious impediment to comparative international research.