Abstract
Prakash S. Gangdev, Community Mental Health Service, Tokoroa Hospital, Tokoroa, New Zealand:
Standardisation of psychiatric diagnoses using universally acceptable nomenclature and definitions is a desirable but rather difficult task. One of the reasons is that often psychiatric terms, which are the building blocks of diagnoses, are used imprecisely or the same concept is given a different label by different authors. Look at the number of texts published for medical students and postgraduates. Unlike other disciplines in medicine where clinical assessment is carried out in a routine, invariate manner (for instance, in internal medicine there is general followed by a systemic examination in a systematic manner, and where for instance, rhonchi are universally understood as a sign of bronchospasm), the signs listed by various authors in the mental state (or status) examination are not always consensual. Thought disorder, as discussed below, is a case in point.
In Review of General Psychiatry [1], thought disorder refers to disorder of thought process (characterised by lack of coherence, goal directedness, logicality) and thought content (e.g. preoccupations, phobias, and perceptual difficulties such as illusions and hallucinations). The inclusion of perceptual disturbances in thought disorder is not a routine practice.
In the Psychiatric Mental State Examination [2], thought disorder is described as disordered connectedness and organisation of thought (such as circumstantiality, flight of ideas, loosening of associations, tangentiality, word salad), and other peculiarities of the thought process (e.g. clang associations, echolalia, neologisms, perseveration, thought blocking).
In the Pocket Handbook of Clinical Psychiatry [3], disordered thought process includes: lack of goal directedness, lossened associations, illogical thinking, tangentiality, irrelevant speech, circumstantiality, rambling, inability to abstract, flight of ideas, clang associations, and perseveration.
In Essential Psychiatry [4], disordered thinking refers to altered stream of thought (characterised by altered speed or discontinuity of thinking) and altered connection between thoughts (e.g. knight's move thinking—positive formal thought disorder, concrete thinking—negative formal thought disorder tested by proverb interpretation).
In the Oxford Textbook of Psychiatry [5], disorder of stream of thought (altered amount or speed of thinking such as pressure of thought, thought blocking), and disorder of form of thought are described. The latter includes flight of ideas (clang associations also included), loosening of associations (e.g. knight's move—derailment, word salad, verbigeration), neologisms, talking past the point, widening of concepts, and perseveration.
In Psychiatry for Medical Students [6], disorder of thinking includes disturbed thought process (altered flow of ideas and quality of associations), disturbed rate and flow (racing thoughts, slowed thoughts, circumstantiality, blocking, perseveration), abnormal associations (loosening of associations, flight of ideas, tangentiality, clanging, punning), and other abnormalities (neologisms, word salad, echolalia).
It is clear from these examples that there is no consensus on the terms used to describe thought disorder. It is possible that they all mean the same thing. But, especially for the students, all this could be rather confusing. Alternatively, it serves to reinforce the impression that psychiatry is very personalised and inexact. It may also have implications for practice and research.
In business, it is a good idea to have competitors (apologies to Bill Gates), but to have so many basic texts with different and competing versions of the mental state examination is not a good idea as this hinders the process of standardising psychiatric practice.
It is important to first universalise the terms used to describe the signs so that the diagnostic criteria may be uniformly applied.