The predelusional state: a conceptual history.

The predelusional state (PDS) is defined as the set of psychopathologic events preceding the crystallization of delusions, and includes strange cognitions, moods, conations, and motor acts that may be fleeting and defy description. This review exclusively deals with the historic aspects of PDS. It is noted that during PDS the patient is expected to report experiences for which, on account of their novelty, he may not even have a name. Thus, it is quite likely that according to culture and personal codes and to the conceptual brief of the interviewer, similar experiences might be reported as depersonalization, bodily sensations, dysphoria, changes in perception of reality or time, dissolution of "ego boundaries," etc. It is therefore not surprising that since the 19th century, PDS has been considered a disorder of cognition, emotions, volition, and consciousness.