The assessment of schizotypy and its clinical relevance.

This article reviews several approaches to assessing schizotypal traits using a wide variety of self-report and interview measures. It makes a distinction between clinical approaches largely based on syndrome and symptom definitions, and psychometric approaches to measuring personality traits. The review presents a brief description of the content and psychometric properties of both sets of measures; these cover both the broad rubric of schizotypy often, but not exclusively based on DSM conceptions, as well as measures with a more specific focus. Measurement of schizotypy has taken place within clinical and nonclinical research utilizing a range of designs and methodologies. Several of these are elucidated with respect to the assessment choices open to researchers, and the implications of the measures chosen. These paradigms include the case-control study, "high risk"/"ultra-high risk" groups, a variety of nonclinical groups and other groups of interest, large scale epidemiology and "in vivo" designs. Evidence from a wide variety of designs continues to provide evidence of the validity of both clinical and personality approaches to schizotypal assessment.