Thought Blocking as a Manifestation of Catatonia: A Case Report.

Catatonia is an underrecognized disorder that has been widely described as a psychomotor syndrome, with little emphasis on its thought and cognitive dimensions. The current Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition, Text Revision describes only motor and behavioral presentations, whereas a few catatonia scales describe only one form of thought disorders, which is thought perseveration. Thought blocking, a disorder of the thought process, is characterized by regular interruptions in the thought stream. It was described by several scholars as a sign of schizophrenia, with few reports describing thought blocking in association with catatonia. In this article, we describe the course of a patient with bipolar I disorder who presented with catatonia and demonstrated thought blocking. Her catatonic symptoms and thought blocking improved with the addition of lorazepam, recurred upon lorazepam discontinuation, and improved with resumption of lorazepam, demonstrating a clear on/off phenomenon. This report highlights the importance of recognizing thought and cognitive manifestations of catatonia, as it can enhance recognition and improve treatment.