Word Salad vs Derailment: Incoherence, With Examples

Word salad vs derailment is a question of where speech breaks. In word salad, which the TLC scale calls incoherence, the breakdown is inside the sentence: words are substituted, connecting words vanish, and the clause itself stops making sense. In derailment, each sentence is fine on its own and the problem is between them, as ideas slip off the track onto obliquely related or unrelated ones (Andreasen, 1986). Word salad is rare and, per the TLC, almost never mild; derailment is the broader category, and its commonest form is a slow, steady slippage.

That one distinction, sentence-level versus between-sentence, is the core test; the TLC adds explicit exclusions and an organic-cause check before the label applies, and notes that incoherence “is often accompanied by derailment,” so both can appear in one reply (Andreasen, 1986). The rest of this guide shows what each sounds like, what to exclude, and how to code them from a transcript.

What is the difference between word salad and derailment?

Word salad (incoherence) breaks speech within the sentence; derailment breaks it between sentences. Andreasen’s Scale for the Assessment of Thought, Language, and Communication (TLC), which grew out of her 1979 definitions and reliability study (Andreasen, 1979a), puts it in one pair of sentences: incoherence “differs from derailment in that the abnormality in incoherence occurs within the level of the sentence or clause, which contains words or phrases that are joined incoherently. The abnormality in derailment involves unclear or confusing connections between larger units, such as sentences or clauses” (Andreasen, 1986).

The practical consequence is that you can read a derailed reply sentence by sentence and follow each one, and only lose the thread when you ask how sentence three relates to sentence one. With word salad you lose the thread inside a sentence. The TLC describes several mechanisms behind that: words substituted so that “the meaning seems to be distorted or destroyed,” word choice that “may seem totally random,” and the deletion of “cementing words,” the conjunctions and articles that hold a clause together (Andreasen, 1986).

A second difference is frequency. Incoherence “is relatively rare. When it occurs, it tends to be severe or extreme, and mild forms are quite uncommon” (Andreasen, 1986). Derailment, by contrast, has mild forms, and the TLC notes its commonest form is a “slow, steady slippage, with no single derailment being particularly severe,” so that the speaker drifts further from the question without noticing. The full item set is covered in our guide to the Thought, Language and Communication scale.

What do word salad examples sound like?

Word salad is speech in which words within a single sentence or clause are substituted, misplaced or stripped of their connecting words, so that the sentence cannot be paraphrased (Andreasen, 1986). The three exchanges below are synthetic and illustrate the mechanisms the TLC lists; the TLC’s own published example opens, to the question of why people believe in God, with “Um, because making a do in life. Isn’t none of that stuff about evolution guiding, isn’t true anymore now” (Andreasen, 1986).

Interviewer: What do you usually do in the mornings?

Speaker: The morning is the kettle under for the greying of it, and then shoes which the bus of, so I am the door by the time of toast or the sister, that is mostly the bread of mornings.

Interviewer: How are you getting on with your flatmate?

Speaker: Flat is the mate of flat, we keep the keeping and the fridge has its own wanting, he told the Thursday it was the Thursday again but the lights, the lights are his sideways.

Interviewer: Tell me about your job.

Speaker: Work was the number of it, boxes to the counting but then counting of the boxes which to the manager said the going and I said the gone, mostly it is the shelf.

Read any of those a second time and notice what is missing. The connecting words are gone or misplaced (“the kettle under for the greying of it”), content words are substituted into slots where they cannot mean anything (“the bread of mornings”), and the sentence does not resolve. Fragments of sense survive, as the TLC notes they can (“portions of coherent sentences may be observed in the midst of a sentence which is incoherent as a whole”), which is exactly why the rating is made at the sentence level, not the word level (Andreasen, 1986).

What do derailment examples sound like?

Derailment sounds like a series of readable sentences that do not belong together. The same three questions, derailed rather than incoherent:

Interviewer: What do you usually do in the mornings?

Speaker: I get up when the kettle goes. Kettles are louder than they used to be, my mother had a whistling one. She never liked the sea, which is why we went to the Lakes. I could do with a holiday.

Interviewer: How are you getting on with your flatmate?

Speaker: He’s fine. He works at the garage on the ring road. Ring roads were a sixties idea, everything was concrete then. I don’t trust concrete, it holds the cold.

Interviewer: Tell me about your job.

Speaker: I stack shelves, mostly tins. Tins last for years, people stockpiled them in the war. My grandfather was in Malta. Malta has a lot of cats.

Every sentence here is grammatical and meaningful. What fails is the connection: kettle to mother to the sea to a holiday is a chain of oblique associations, not an answer. The TLC calls this “lack of cohesion between clauses and sentences” with “unclear pronoun referents,” and notes that the speaker typically shows no awareness that the reply has left the question behind (Andreasen, 1986). For the manic, rapid form of the same slippage, see pressured speech vs flight of ideas.

How do you tell word salad from derailment, aphasia and dialect?

By level first (within the sentence for incoherence vs derailment, which is between sentences), then by rarity, then by the TLC’s explicit exclusions and its aphasia check (Andreasen, 1986). The table puts the decision in one place, including the loose associations vs word salad pair that older textbooks ran together.

Pattern	Where it breaks	Is each sentence readable?	TLC rating
Incoherence (word salad)	Inside the sentence or clause	No	Incoherence; rare, usually severe
Derailment (loose associations)	Between sentences or ideas	Yes	Derailment; has mild forms, often a steady slippage
Tangentiality	Between the question and the reply	Yes	Tangentiality, only as a reply to a question
Word-searching, false starts	Inside the sentence, but self-corrected	Yes, with effort	Not rated: an explicit TLC exclusion
Dialect, idiom, low education	Grammar differs from the standard	Yes	Not rated: an explicit TLC exclusion
Wernicke's or jargon aphasia	Inside the sentence	No	Not called incoherence until organic causes are excluded

The exclusions are where coding goes wrong. The TLC gives its own counter-examples: a speaker who says “My father, he, for a long time, well, he just started . . . he joined the church” is searching for words, not incoherent; and constructions such as “He ain’t got no family” or “The lawn needs mowed” are regional or educational, and “should also not be rated as incoherence” (Andreasen, 1986). A transcript full of restarts from a nervous speaker is noise, not a sign.

Aphasia is the exclusion with the highest stakes. The TLC states that incoherence “may sound quite similar to a Wernicke’s aphasia or jargon aphasia,” and that in those cases the disorder “should only be called incoherence (thereby implying a psychiatric disorder as opposed to a neurological disorder) when history and laboratory data exclude the possibility of a known organic etiology and formal testing for aphasia is negative” (Andreasen, 1986). A rater working from a transcript cannot make that exclusion. They can describe the speech and flag it.

Is word salad only a sign of schizophrenia?

No. Word salad, or incoherence, is not specific to schizophrenia: in Andreasen’s earlier comparison of patients with mania, depression and schizophrenia, incoherence, derailment, tangentiality, illogicality and loss of goal occurred at similar rates in mania and schizophrenia, (Andreasen, 1979b). What separated schizophrenia was impoverished speech, poverty of speech and poverty of content, rather than the florid signs that popular descriptions of word salad schizophrenia emphasize. The DSM-5 diagnostic criteria for schizophrenia nonetheless list “disorganized speech (e.g., frequent derailment or incoherence)” as one of the Criterion A symptoms, which is why both terms appear in every textbook account (American Psychiatric Association, 2013).

The TLC paper makes the broader point that these behaviors “also occur in the speech of people who do not meet the criteria for any psychiatric diagnosis, particularly when they are fatigued or stressed” (Andreasen, 1986). The TLC’s passage lists behaviors such as associative loosening, clanging and blocking rather than naming incoherence; because the paper describes incoherence as seldom mild, the caveat probably applies to it far less, but that is our inference. A rater describes the pattern; the clinician with the history decides what it means. The positive-symptom version of both items, with 0 to 5 scoring, lives in the SAPS positive thought disorder subscale; the two instruments are compared in TLC vs SAPS.

How do you code incoherence and derailment from a transcript?

Code both as spans, at different sizes. Incoherence is tagged at the sentence or clause that fails; derailment is tagged at the join between two ideas where the slip happens. That is instance-level coding, the approach in evidence mode vs instance mode annotation, and it is what makes the ratings checkable by a second coder.

A synthetic exchange with the decisions marked:

Interviewer: What happened at the appointment?

Speaker: The doctor was late. Late is a kind of weather, my aunt was always late, she had the house in Tynemouth. [Derailment: three readable sentences; the slip is at “Late is a kind of weather”] And the house of the under-doctor with the clock, which for the pills of the window I said the when of it. [Incoherence: the clause itself does not resolve; connecting words misplaced, content words in impossible slots] Then I got the bus home.

Three rules keep it honest. Rate incoherence only where the sentence itself is unreadable; if you can paraphrase it, it is not incoherence, however odd. Before tagging incoherence, check the exclusions: is this word-searching, dialect, or a restart? And when speech looks incoherent throughout, do not infer a psychiatric cause from the transcript; note that aphasia has not been excluded, because the TLC requires that exclusion before the label applies (Andreasen, 1986).

Done this way, the two signs stop being impressions and become spans two coders can compare. The TLC reports its kappas from raters using shared written definitions, and its reliability sample of 113 was mixed (32 with mania, 36 with depression, 45 with schizophrenia), so the agreement figures are not schizophrenia-only numbers (Andreasen, 1986).

What are the most common mistakes when coding word salad vs derailment?

The most common mistakes are rating derailment as incoherence because the reply is hard to follow, rating word-searching or dialect as incoherence, and treating word salad as a diagnosis. Each has a fix:

• Promoting derailment to incoherence. If each sentence can be paraphrased, it is derailment. Incoherence is unreadable at the clause level (Andreasen, 1986).
• Rating restarts and word-searching. “He, for a long time, well, he just started” is an explicit TLC exclusion, not a sign.
• Rating dialect or idiom. “He ain’t got no family” is grammar, not thought disorder; the TLC lists it as an exclusion (Andreasen, 1986).
• Expecting mild word salad. The TLC says mild forms are uncommon. If you are rating a lot of mild incoherence, you are probably coding something else.
• Skipping the aphasia exclusion. From a transcript, you cannot rule out Wernicke’s or jargon aphasia. Describe and flag; do not label.
• Reading a diagnosis into the sign. Incoherence and derailment did not separate mania from schizophrenia in Andreasen’s sample (Andreasen, 1979b).

So: word salad vs derailment is settled at the level of the sentence: if the sentence itself has come apart, it is incoherence, rare and severe; if the sentences are whole and the thread between them is not, it is derailment, whose commonest form is a slow, steady slippage (Andreasen, 1986).

References

• Andreasen, N. C. (1986). Scale for the Assessment of Thought, Language, and Communication (TLC). Schizophrenia Bulletin, 12(3), 473–482. doi:10.1093/schbul/12.3.473
• Andreasen, N. C. (1979a). Thought, language, and communication disorders. I. Clinical assessment, definition of terms, and evaluation of their reliability. Archives of General Psychiatry, 36(12), 1315–1321. doi:10.1001/archpsyc.1979.01780120045006
• Andreasen, N. C. (1979b). Thought, language, and communication disorders. II. Diagnostic significance. Archives of General Psychiatry, 36(12), 1325–1330. doi:10.1001/archpsyc.1979.01780120055007
• American Psychiatric Association. (2013). Diagnostic and Statistical Manual of Mental Disorders (5th ed.). Arlington, VA: American Psychiatric Publishing. doi:10.1176/appi.books.9780890425596

If you code disorganized speech from transcripts, Tagaroo curates the TLC thought, language and communication items and the SAPS positive thought disorder subscale as span-level annotation schemes, with the sentence-level rule above built into the coding guidance and inter-rater reliability computed as your coders work. The question-triggered pair of drift signs is covered in tangentiality vs circumstantiality.