The American Psychiatric Association (APA) has updated its Privacy Policy and Terms of Use, including with new information specifically addressed to individuals in the European Economic Area. As described in the Privacy Policy and Terms of Use, this website utilizes cookies, including for the purpose of offering an optimal online experience and services tailored to your preferences.

Please read the entire Privacy Policy and Terms of Use. By closing this message, browsing this website, continuing the navigation, or otherwise continuing to use the APA's websites, you confirm that you understand and accept the terms of the Privacy Policy and Terms of Use, including the utilization of cookies.

×
ArticleNo Access

A Classificatory Principle in Schizophrenia

Published Online:https://doi.org/10.1176/ajp.126.11.1655

In an attempt to develop reliable criteria for symptoms unique to the schizophrenic syndromes, the author offers an Index of Formal Signs of thought disorder. Using the theory that language normally shows differentiation over time, he measures the form rather than the content of thought. The index was shown to be reliable when its ratings were compared with other clinical ratings.

Access content

To read the fulltext, please use one of the options below to sign in or purchase access.