Mania in the Swedish Twin Registry: criterion validity and prevalence

Abstract

The performance of the telephone screening for mania by lay interviewers in terms of positive predictive power was not satisfactory; despite a high specificity, the false positive rate was high. The low population prevalence of mania, non-response bias, criterion choice and inherent limitations of the interviewing method are among the explanations. Assessment of a lifetime manic episode based on lay interviewer screening may yield misleading data.