The specificity of Bleulerian and Schneiderian symptoms: a critical reevaluation.

Schneider's FRS's seem to carry diagnostic weight for schizophrenia when "massively" present and when known organic psychoses are excluded. However, at least 10 per cent of affectively ill probands, especially manics, have also been shown to have at least one FRS. The main problems in their clinical application is their low sensitivity (on the average less than 50 per cent), and the possibility that those without extensive training in the phenomenologic approach may overendorse their presence, thereby diluting the specificity of the test.