SCHIZOPHRENIA AND HALLUCINATIONS

The term schizophrenia stems from the Greek wordsschizein(to split), andphren(nerve, diaphragm, heart). It was introduced in 1908 by the Swiss psychiatrist Paul Eugen Bleuler (18571939) to denote a group of mental disorders displaying certain similarities to Emil Kraepelin's (1856-1926) dementia praecox. Today the validity of the two nosological concepts is debated, but in clinical and scientific practice the notion of schizophrenia is still in use. Among individuals with a DSM diagnosis of schizophrenia, hallucinations are reported in some 80% of the cases. " Auditory hallucinations are the most prevalent form, with a lifetime prevalence of 56-70%. "Visual hallucinations are reported in 29-56% of the cases."Olfactory hallucinations tend to be underreported, but lifetime prevalence rates range from 11 to 36%. In individuals with a DSM diagnosis of schizophrenia, other types of hallucination can and do occur as well, albeit less frequently. In clinical practice virtually any type of hallucination may be encountered in these individuals, including " autoscopic hallucinations, " brobdingnagian hallucinations, "compound hallucinations, "extracampine hallucinations, " formicative hallucinations, " gustatory hallucinations, " kinaesthetic hallucinations, " lilliputian hallucinations, " musical hallucinations, " negative hallucinations, "proprioceptive hallucinations, "reflex hallucinations, "scenic hallucinations, " sexual hallucinations, and " somatic hallucinations. In addition, one may encounter sensory deceptions such as "synaesthesias and " illusions and sensory distortions such as " metamorphopsias.

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