THE LATENT STRUCTURE OF SCHIZOTYPY .1. PREMORBID INDICATORS OF A TAXON OF INDIVIDUALS AT RISK FOR SCHIZOPHRENIA-SPECTRUM DISORDERS

A taxometric analysis (R.R. Golden & P.E. Meehl, 1979) was conducted t o test the hypotheses that liability for schizophrenia-spectrum disord ers is dichotomously distributed and that this liability can be detect ed premorbidly with behavioral indicators analogous to many of the cri teria for schizotypal personality disorder. Behaviors were assessed in 207 offspring of schizophrenic mothers and 104 matched offspring of n ormal parents in 1962, when participants' mean age was 15 years. Diagn oses on the basis of the Diagnostic and Statistical Manual of Mental D isorders (3rd ed., rev.; American Psychiatric Association, 1987) were made in 1986-1989, when participants were nearly through the risk peri od for developing schizophrenia. The aggregation of indicators was con sistent with a bimodal latent liability distribution. Membership in th e schizotypal class was a sensitive and specific predictor of the emer gence of schizophrenia-spectrum disorders in adulthood.