15th November 2023

How is Formal Thought Disorder Measured?

There are two commonly used scales:

• Thought language & communication scale (Andreasen, 1979), which provides concise definitions of a range of features of thought disorder. The patient is assessed clinically, and the clinician rates the degree of disorder present in the patient’s speech. The reliability was found to be ‘quite good for most of the terms defined.’ One problem with this scale is that not all formal thought disorder types are included.
• Thought disorder index (Johnston & Holzman, 1979), which is similar but has been shown to be more sensitive. The assessment involves two standardised procedures: answering questions about the Rorschach ink-blots and performing a Wechsler adult intelligence scale. Unfortunately, this is simply too time consuming for clinical practice, and the scoring requires an expert to perform; therefore, it remains a research tool.

References

• Andreasen, N. C. (1979). Thought, language, and communication disorders: I. Clinical assessment, definition of terms, and evaluation of their reliability. Archives of General Psychiatry, 36, 1315-‐-1321
• Johnston, M. H., Holzman, P. S. (1979). Assessing Schizophrenia Thinking. San Francisco, CA: Jossey-Bass.
• Prathap, S. (2019). SPMM Smart Revise. SPMM Course.