[Schizophrenia and age]

Abstract

The association of age with time of onset, symptomatology and early course of schizophrenia was studied on a large, representative sample of first-admitted patients with a diagnosis of schizophrenia (nuclear and related diagnoses) from a total population of about 1.5 million by using a semi-structured interview (IRAOS) developed specifically for this purpose. As a result an age distribution differing between men and women was obtained when the appearance of the first sign of a mental disturbance was studied. 61.6% of the men and 47.4% of the women fell ill prior to the age of 25. Negative symptoms and the early course of the disease turned out to be relatively independent of age at onset. The few age differences observed with positive and unspecific symptoms seem to be accounted for by factors not specific for schizophrenia, such as slightly increased anxiety at young age, slightly increased depressiveness in early adulthood and slightly increased paranoid delusions later in adulthood. At young age delusional symptoms, probably as an expression of immature personality, are less stable, less differentiated and less systematized, whereas fully developed delusions of persecution become more frequent at higher age. An unexpected finding was a comparatively high proportion of lengthy phases characterized by negative symptoms prior to first admission in late-onset schizophrenia in females. Hence, beginning schizophrenia seems to be a fairly uniform pattern of response at all ages, female sex appearing to be the only factor independent of the disease that influences it to any significant extent by delaying onset.