Validity and usefulness of the Wisconsin Manual for Assessing Psychotic-like Experiences.

The Wisconsin Manual for Assessing Psychotic-like Experiences is an interview-based assessment system for rating psychotic and psychotic-like symptoms on a continuum of deviancy from normal to grossly psychotic. The original manual contained six scales, assessing thought transmission, passivity experiences, thought withdrawal, auditory experiences, personally relevant aberrant beliefs, and visual experiences. A seventh scale assessing deviant olfactory experiences was subsequently added. The rating scales have good interrater reliability when used by trained raters. Cross-sectional studies indicated that the frequency and deviancy of psychotic-like experiences are elevated among college students who were identified, hypothetically, as psychosis prone by other criteria. Psychotic-like experiences of moderate deviancy in college students successfully predicted the development of psychotic illness and poorer overall adjustment 10 years later. The manual is useful for identifying psychosis-prone individuals and is recommended for use in linkage and treatment outcome studies. The present article provides an interview schedule for collecting information required for rating psychotic-like experiences.