Date of Award

Spring 1989

Document Type





Defining, studying, and explaining schizophrenia has always been a difficult undertaking. One major problem is differentiating it from other major disorders. Another problem is determining whether schizophrenia is a single disorder or a cluster of related disorders. A third issue is the validity and reliability of the diagnostic criteria for schizophrenia defined in The Diagnostic and Statistical Manual of Mental Disorders. Third Edition (DSM-III); which states that schizophrenia cannot be diagnosed in an individual exhibiting the symptoms for the first time after age 45. However, since many researchers and clinicians come into contact with people over the age of 45 who appear to display the symptoms of schizophrenia for the first time, many terms have been used to classify these "schizophrenics.” The purpose of this thesis is to describe the variations in behavioral symptom patterns of schizophrenia as a function of age of onset. The most common age used to divide early-onset versus late-onset is 45. Minor differences were discovered between the two age groups. Schizophrenics with late-onset were usually female, subtyped as paranoid, and responded well to low doses of neuroleptics. Younger schizophrenics were usually male, and did not respond as well to treatment (Jeste et al, 1988). Results suggest
similarities between early-onset and late-onset schizophrenia.