Problems With the Waldrop Scale

To the Editor: The interesting article by Baher Ismail, M.D., and colleagues (1) demonstrated that higher levels of minor physical anomalies characterize both patients with schizophrenia and their normal siblings. Dr. Ismail et al. used an extended measure consisting of the Waldrop scale and 23 other minor physical anomalies as a diagnostic instrument. The authors stated that the Waldrop scale identifies minor physical anomalies strongly associated with schizophrenia, and assessment of the new items clearly indicates that many additional minor physical anomalies are found in patients with schizophrenia.

We have evaluated problems with the Waldrop scale and emphasized that it makes no distinction between minor malformations, which arise during organogenesis, and phenogenetic variants, which appear after organogenesis (2). In other words, minor malformations are always abnormal and can point to problems during organogenesis, but phenogenetic variants are developmentally identical to normal variants. The authors ignore such a distinction in their assessment.

Buckley (3) criticized the Waldrop scale, which lacks good normative data, assesses features that are probably of limited relevance to schizophrenia, and contains mostly items with no test-retest reliability.

We agree with the authors that the addition of new minor physical anomaly items to the assessment would add valuable information concerning minor physical anomalies in patients with schizophrenia. We suggest the need, however, for distinguishing minor malformations from phenogenetic variants on new extended scales for a better understanding of the time and nature of the supposed insult.