ABSTRACT | PDF

Seminar I

Disorder of Thought

Diganta Kumar Das
Postgraduate Trainee of Psychiatry
Silchar Medical College and Hospital

Definition: Any disturbance of thinking that affects language, communication or thought content is called thought disorder. It is hallmark feature of schizophrenia. Manifestation ranges from simple blocking and mild circumstantiality to profound loosening of association, incoherence and delusion, characterised by a failure to follow semantic and syntactic rules that is inconsistent with the person’s education, intelligence or cultural background.

In psychiatric examination, two aspects of abnormality of thought are considered:
1. Content of thought – Abnormality of content of thought, e.g. delusion.
2. Abnormality of form of thought – Form means “the arrangement of parts”. Disturbance in the form of thought are disorder in the logical connections between ideas.

The form of thought is largely assessed by examining the speech of the patient. Thought is also reflected in behaviour. But behaviour is also dependent on factors like personality, motivation and other cognitive processes like memory and orientation. Formal thought disorder typically refers to marked abnormality in the form and flow of thought.

Disturbance in the flow and form Disturbance in the flow and form can be divided into those reflecting in rate, continuity, control and complexity.

(A) Rate: Thinking can be slow, retarded or accelerated, e.g. thinking is retarded in depression.

Thought blocking – There is sudden break in the train of thought, e.g. in schizophrenia.

Thought withdrawal – Here the patient feels that some alien force has intentionally withdrawn the thought from the consciousness, seen in schizophrenia.

Accelerated rate of thinking is accompanied by fast speaking. It can be seen in normal variant as in radio, auctioneers who reflects learned psychomotor skills.

(B) Continuity: Disorders in continuity of thought are –

Circumstantiality: Here the flow of thought includes many digressive associations, often including many unnecessary details. But however the speaker returns to the intended point.

Tangentiality: Here the person wanders away from the intended point moving further away and never returns to the original idea.

Loose association: Severe derailments, in which the flow of idea is no longer comprehensible to the listener, since the individual thoughts seem to have no logical relation to one another.

Word salad: Word salad is stringing of words together that seems to have no logical association.

Verbigeration: Verbigeration is the disappearance of the understandable speech which is replaced by mere utterance.

Clang association: Clang association is the sequence of thought stimulated by the sound of the preceding word, e.g. I will kill – with a drill – etc.

Echolalia: Here the patient repeats the sentence just uttered by the examiner. Palilalia is utterance of one word or phrase.

Preservation: A sentence or phrase in repeated several times after it is no longer relevant.

Punning: Utterance of phonetically similar words.

(C) Control

Delusional passivity experience: Here the patient experience that his own thoughts are being under control of other force. These experiences are – 

Thought insertion, thoughts are placed under the patient’s mind from outside.

Thought withdrawal, thoughts are whisked out of mind.

Thought broadcast, thoughts are escaping from his mind to be heard by others.

Obsessional thinking: Obsessive thinking is stereotype repetitive, persistent thinking that are realised as one’s own thought.

(D) Complexity: It is related to impaired capacity to think abstractly. Abstract thinking is the ability to assume a mental set to keep simultaneously in minds all the aspects of a complex situation and to abstract a common property.

Disturbances in the ability to form concept is called concrete thinking.

Disturbance in the content of thought Normal contents of thought are composed of awareness, concern, belief, preoccupation, imagination and strength. Content of thought that are consistent with a sense of self, compatible with the person’s self image is called ego-syntonic.

Delusions are false belief that are strongly held and immutable in the face of refuting evidence, and that are not consistent with the person’s educational, social and cultural background. Delusions may be –

(i) Simple: Contains relatively few elements.

(ii) Complex: Contains extensive elaboration of people, spirits, motives and situation.

(iii) Systematised: Systematised delusions are restricted to well delineate areas and associated with clear sensorium.

(iv) Nonsystematised: Delusions that are extended up to many aspects of life, new data, people and situation.

(v) Complete delusions are held utterly without any doubt.

(vi) In partial delusion, the patient entertains doubt about the delusional idea or belief. 

(vii) Primary delusions are those that are not understandable in terms of patient’s culture or mood, also called autochtonous delusion. It occurs in an instant without identifiable preceding event. These primary delusions are –

Delusional percept is a normal perception with a delusional meaning.

Delusional atmosphere or mood is a state of perplexity, a sense that something odd is going on that involves the patient but in unspecified way.

Delusional memory is the memory of an event which is completely delusional.

(viii) Secondary delusion is a delusion that takes place in an instant with identifiable preceding event e.g. theme of guilt or worthlessness in depression.

Some classical types of delusion are delusion of persecution, delusion of grandeur, delusion of influence, delusion of having sinned, nihilistic delusion, somatic delusion, delusion of double (doppelganger i.e. meaning another person physically transformed to themselves), delusion of jealousy, delusion of mood, delusion of memory, delusion of erotic attachment (Clerambault’s syndrome), delusion of replacement of significant others (Capgras’ syndrome i.e. replaced by exact double), delusion of disguise (Fregoli’s phenomena i.e. strangers are identified as familiar person), shared delusion (folie a  deux, folie a trios, folie a famille).

Overvalued ideas are unreasonable and sustained abnormal beliefs that are held beyond the bounds of reason. However these are not unbelievable like most delusion. Some features of overvalued ideas are it is a preoccupied idea, predominates person’s way of life, not obsessional in quality or ego-dystonic, sometimes accepted by other members of family/population.

Frank Fish classified disorder of thinking into – 
I. Disorder of stream of thought
II. Disorder of possession of thought
III. Disorder of control of thought
IV. Disorder of form of thought

I. Disorder of stream of thought
(A) Disorder of tempo
• Flight of ideas
• Inhibition or retardation of thinking
• Circumstantiality
(B) Disorder of continuity of thought
• Perseveration
• Thought blocking
II. Disorder of possession of thought
• Obsession and compulsion
• Thought alienation
III. Disorder of content of thought
Delusion
(a) Primary delusion: delusional mood, delusional perception and sudden delusional idea.
(b) Secondary: Secondary delusions and systematisation – delusion of persecution, love, jealousy, grandeur, ill health, guilt, poverty and nihilistic delusion.
IV. Disorder of form of thought Disorder of form of thinking is also called formal thought disorder. This is disorder of conceptual or abstract thinking. Here there are two types of formal disorder:
(a) Negative type – patient lost his previous ability to think and cannot produce a concept.
(b) Positive type – patient produces false concept by blending together incongruous elements.

Bleuler regarded schizophrenia as a disorder of association and pointed out that the outstanding feature of schizophrenic formal thought disorder was the lake of connection between association which gave rise to changeable and unclear concept. He believed that this was result of condensation and displacement and misuse of symbols. Cameron stresses that schizophrenic has got overinclusion as an outstanding feature of formal thought disorder. Their speech has private personal idioms or ‘metonyms’ and private fantasy. Goldstein claims in schizophrenia and coarse brain disease the thinking becomes concrete. Disorder of form of thinking typically occurs in schizophrenia. This has five features (Schneider): derailment, substitution, omission, fusion and driveling.

Bibliography
1. Hamilton M, editor. Fish’s clinical psychopathology. 2nd ed. Bombay: Varghese Publishing House; 1994.
2. Sadock BJ and Sadock VA. Synopsis of psychiatry. 10th ed. Philadelphia: Lippincot Williams and Wilkins; 2007. 
3. Sadock BJ, Sadock VA, Ruiz P, editors. Comprehensive textbook of psychiatry. 9th ed. Philadelphia: Lippincot Williams and Wilkins; 2009.

 

Creative Commons License
This work is licensed under a Creative Commons Attribution-ShareAlike 4.0 International License.

Nach oben