Thinking Process Abnormalities in Schizophrenia

From distractibility to incoherence

a thought
a thought. Matt Anderson via Flickr

Man is but a reed, the weakest in nature, but he is a thinking reed.

Blaise PascalThoughts, Chapter II. 10; Reported in Hoyt's New Cyclopedia Of Practical Quotations (1922), p. 787-90

Some argue that thinking is the essence of what makes us human. In a specific sense thinking refers to an individual ‘s ability to make decisions and solve problems.

In a broader sense thinking refers to the totality of experiences that happen inside one’s mind.

This includes thoughts but also emotions, sensations, memories and fantasies, which are the essential building blocks of the thinking “function”. “Sensible” thinking usually implies that the building thinking blocks have an understandable relationship with the world out there.

However thinking is far from being a simple, static sum of these components; in fact thinking is a process that links together all the disparate “thinking blocks” in a way that makes sense to both the individual and the word. While necessary, sensible building blocks are not sufficient to make for “sound thinking”, implying that the underlying thinking blocks are aligned in an orderly fashion, usually defined by attributes such as “logical” and “goal directed”.

It then makes sense to try to understand thinking from two perspectives:

  1. Thought content
  2. Thought process

Other articles discuss thought content abnormalities in schizophrenia, which typically include abnormal sensorial perceptions, such as auditory hallucinations (hearing voices and noises that are not based in reality), or delusions, fixed, rigid, self-justified sets of ideas that are at odds with reality.

This article focuses on thought process abnormalities in schizophrenia.

Thought process refers to how the building bricks of thinking (thoughts, emotions/feelings, sensations – including the sense of self, memories and fantasies) are linked to one-another.  From a process perspective normal thinking is logical, coherent, goal directed.

Simply put, it makes sense. Unfortunately, this normality is rarely encountered in patients suffering from schizophrenia. In fact, schizophrenia is often referred to as a “formal thought disorder” because disordered or illogical thinking is one of its more common signs.

For some patients the degree of “disordered thinking” is mild resulting in distractibility:

"Then I left San Francisco and moved to... where did you get that tie?" (Andreasen 1986)

Alternatively, the connections might be over-inclusive, leading to the impression that the individual’s thoughts are going in circles before finally coming to the point, a process that called circumstantial thinking:

“I really got mad as I was waiting at the grocery store. I always go to this one grocery story. I like it usually. The always have local produce. I like that. They get some of it from this farm where I used to work many years ago. I still go there sometimes. The owner is really nice. I also know his kids, they were small when I was working there.

They are big now. They send produce to a few stores, this store that I like is one of them. But they send it to quite a few other places. Everybody likes them.” [The story eventually returns to why the individual got angry at the grocery story but it takes quite a few detours before coming back to the point].

Andreasen gives the example of a patient, who in response to  “What is your name?” stated "Well, sometimes when people ask me [the interviewer asked: I have to think about whether or not I will answer because some people think it's an odd name even though I don’t really because my mom gave it to me and I think my dad helped but it's as good a name as any in my opinion but yeah it's Tom." (Andreasen 1986)

Moderately disordered thinking includes tangential thinking, seen when the thoughts continue to be somewhat connected but in a rather superficial or tangential way:

“I really got mad as I was waiting in line at the grocery store. I cannot stand lines. Waiting and waiting. I waited for a long time to get my drives license. Driving these days is just crazy. “

In cases of severely disordered thinking, thoughts lose almost all connections with one another, they become disconnected, disjointed, leading to what doctors call derailment or loose associations. The terms are self-explanatory: the thinking process is frequently derailed, characterized by very weak or loose associations:

‘I always liked geography. My last teacher in that subject was Professor August A. He was a man with black eyes. I also like black eyes. There are also blue and grey eyes and other sorts, too…’ (Bleuler 1911 ⁄ 1950).

‘I really enjoyed some communities and tried it, and the next day when I’d be going

out you know, um I took control like uh, I put, um, bleach on my hair in, in California.

My roommate was from Chicago and she was going to the junior college. And we lived in the YMCA so she wanted to put it, um, peroxide on my hair…’ (Andreasen 1986)

A particular case of loose associations is when the individual associates unrelated concepts based on the fact they rhyme, a thinking process abnormality that is described as clang associations:

At times, made-up words or neologisms are frequently present:

"I got so angry I picked up a dish and threw it at the geshinker." (Andreasen 1986)

"I'm not trying to make noise. I'm trying to make sense. If you can't make sense out of nonsense, well, have fun." (Andreasen 1986)

In very severe cases, only the word structure is preserved but there are no discernable connections between words. It’s impossible to understand the individual’s thinking; this type of thought process abnormality is called incoherence or word salad:

To the question "Why do people comb their hair?" Andreasen reports that a patient stated: "Because it makes a twirl in life, my box is broken help me blue elephant. Isn't lettuce brave? I like electrons. Hello, beautiful." (Andreasen 1986)

In schizophrenia disorganized thinking is classified as one of the positive symptoms.

While some degree of thought process disorders in seen in many individuals with schizophrenia, thought disorder is also seen in individuals with other psychiatric problems, most notably individuals with severe autism,  severe mania, and severe depression.


Andreasen NC. Thought, language, and communication disorders. I. A Clinical assessment, definition of terms, and evaluation of their reliability. Archives of General Psychiatry 1979;36(12):1315-21. PMID 496551.

Bleuler, E. 1911 ⁄ 1950. Dementia praecox, or the group of schizophrenias. New York: International Universities Press.

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