The Chapman Scales

Chapman and colleagues [149-154] produced a list of early symptoms by studying first-episode cases of schizophrenia retrospectively. They focused on the cognitive character of the changes preceding the psychotic symptom pattern - disturbances of attention, perception and memory - supplemented by indicators of psychomotor functioning. They were the first to develop experimental procedures for assessing disordered perception on this observational basis. Proceeding from the construct of ''psychosis proneness'', they developed several scales for the assessment of psychotic and psychotic-like experiences [153]: the 35-item Perceptual Aberration Scale, the 30-item Magical Ideation Scale, the Impulsive Nonconformity Scale (51 items) and the Social Anhedonia Scale (40 items). The scales were tested for internal consistency and retest reliability. The authors concluded that their scales are suited to identifying persons with schizophrenia proneness, but not to reliably predicting schizophrenia risk, nor do the scales permit one to distinguish between risk for schizophrenia and other types of psychotic disorder or affective illness with psychotic symptoms. If we enter the numbers of psychotic transitions as based on psychosis proneness in the four-cell matrix for calculating the usual indices of diagnostic efficiency, the probands identified by the two subscales tested as valid and the control group yield a high sensitivity of 0.92, an extremely low rate of false negatives (0.003%) and a negative predictive power of 99%. In contrast, the values for specificity (0.43), false positives (55%) and positive prognostic power (5.6%) are less favourable. The conclusion that the number of people with psychosis proneness by far exceeds the number of persons ever falling ill with schizophrenia may be correct, but it also means that the concept is hardly suitable for identifying persons at risk for psychosis if the aim is to refer them to treatment. Nevertheless the concept can be used for screening purposes, because it is fairly easy to use and helps to identify all at-risk persons at an early stage (10 to 15 years before the onset of psychotic symptoms).

BiPolar Explained

BiPolar Explained

Bipolar is a condition that wreaks havoc on those that it affects. If you suffer from Bipolar, chances are that your family suffers right with you. No matter if you are that family member trying to learn to cope or you are the person that has been diagnosed, there is hope out there.

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