Dimensional structure of the Frankfurt Complaint Questionnaire

The Frankfurt Complaint Questionnaire (FCQ) was designed to evaluate the subjective symptoms of schizophrenics. Several validation studies of the FCQ using principal components analyses (PCA) have shown one-, two-, or four-factor solutions. The present study was conducted using FCQ data on 310 schizophrenics who met the ICD-10 criteria for F20 (schizophrenia) disorder. Using several guidelines to select the number of factors, the PCA yielded one factor. This result suggests a unidimensionality underlying FCQ items. A new scale comprising 24 items was derived from those items with higher weights in the first factor.