In psychiatry

Psychiatry

Psychiatry is the medical specialty devoted to the study and treatment of mental disorders. These mental disorders include various affective, behavioural, cognitive and perceptual abnormalities...

, thought disorder (TD) or formal thought disorder (FTD) is a term used to describe incomprehensible language, either speech

Interpersonal communication

Interpersonal communication is usually defined by communication scholars in numerous ways, usually describing participants who are dependent upon one another. It...

 or writing

Writing

Writing is the representation of language in a textual medium through the use of a set of signs or symbols . It is distinguished from illustration, such as cave drawing and painting, and non-symbolic preservation of language via non-textual media, such as magnetic tape audio.Writing most likely...

, that is presumed to reflect thinking. There are different types. For example, language may be difficult to understand if it switches quickly from one unrelated idea to another (flight of ideas) or if it is long-winded and very delayed at reaching its goal (circumstantiality) or if words are inappropriately strung together resulting in gibberish (word salad

Word salad (mental health)

In the mental health field, schizophasia, commonly referred to as word salad, is confused, and often repetitious, language that is symptomatic of various mental illnesses....

).

Psychiatrists consider Formal Thought Disorder as being one of two types of "thinking" or "thought" disorders. The other type being delusions. The latter involves "content" while the former involves "form". Although the term "thought disorder" can refer to either type, in common parlance it refers most often to a disorder of thought "form" also known as Formal Thought Disorder.

It is usually considered a symptom of psychotic

Psychosis

Psychosis means abnormal condition of the mind, and is a generic psychiatric term for a mental state often described as involving a "loss of contact with reality"...

 mental illness

Mental illness

A mental disorder or mental illness is a psychological or behavioral pattern generally associated with subjective distress or disability that occurs in an individual, and which is not a part of normal development or culture. Such a disorder may consist of a combination of affective, behavioural,...

, although it occasionally appears in other conditions. For example, pressured speech and flight of ideas may be present in mania

Mania

Mania, the presence of which is a criterion for certain psychiatric diagnoses, is a state of abnormally elevated or irritable mood, arousal, and/ or energy levels. In a sense, it is the opposite of depression...

. Clanging

Clanging

In psychology and psychiatry, clanging or clang association refers to a mode of speech and logical association to two or more words primarily based upon word sounds when no logical association between the words exists. For example, rhyming or alliteration may lead to the appearance of logical...

 or echolalia

Echolalia

Echolalia is the automatic repetition of vocalizations made by another person. It is closely related to echopraxia, the automatic repetition of movements made by another person....

 may be present in Tourette syndrome

Tourette syndrome

Tourette syndrome is an inherited neuropsychiatric disorder with onset in childhood, characterized by multiple physical tics and at least one vocal tic; these tics characteristically wax and wane...

. Eugen Bleuler

Eugen Bleuler

Paul Eugen Bleuler was a Swiss psychiatrist most notable for his contributions to the understanding of mental illness and for coining the term "schizophrenia."-Biography:...

, who named schizophrenia

Schizophrenia

Schizophrenia is a mental disorder characterized by a disintegration of thought processes and of emotional responsiveness. It most commonly manifests itself as auditory hallucinations, paranoid or bizarre delusions, or disorganized speech and thinking, and it is accompanied by significant social...

, held that its defining characteristic was a disorder of the thinking process. However, Formal thought disorder is not unique to schizophrenia or psychosis. So-called “organic” patients with a clouded consciousness, like that found in delirium

Delirium

Delirium or acute confusional state is a common and severe neuropsychiatric syndrome with core features of acute onset and fluctuating course, attentional deficits and generalized severe disorganization of behavior...

, also have a formal thought disorder. However, there is a distinct clinical difference between the two. Schizophrenic or psychotic patients never demonstrate awareness nor concern about it because it results from a fundamental inability to use the same type of Aristotelian logic as everyone else does whereas so-called “organic” patients with a clouded consciousness usually do demonstrate awareness and concern about it, by complaining about being “confused” or “unable to think straight” because it results, instead, from various cognitive deficits.

Possible signs and symptoms of thought disorder

Thought is revealed through speech. Thus, observation of patterns of thought naturally involves close observation of the speech of the individual being considered. Although it is normal to exhibit some of the following during times of extreme stress (e.g. a cataclysmic event or the middle of a war) it is the degree, frequency, and the resulting functional impairment that leads to the conclusion that the person being observed has a thought disorder.

• Blocking
  Thought blocking
  Thought blocking, a phenomenon that occurs in people with psychiatric illnesses , occurs when a person's speech is suddenly interrupted by silences that may last a few seconds to a minute or longer. Blocking is often brought on by questioning or discussing something of particularly large personal...
  
  – Interruption of train of speech before completion. e.g. "Am I early?" "No, you're just about on..."(silence) At an extreme degree, after blocking occurs, the speaker does not recall the topic he or she was discussing. True blocking is a common sign of schizophrenia
  Schizophrenia
  Schizophrenia is a mental disorder characterized by a disintegration of thought processes and of emotional responsiveness. It most commonly manifests itself as auditory hallucinations, paranoid or bizarre delusions, or disorganized speech and thinking, and it is accompanied by significant social...
  
  .
• Circumstantiality – Speech that is highly detailed and very delayed at reaching its goal. Speaking about many concepts related to the point of the conversation before eventually returning to the point and concluding the thought. Excessive long-windedness. e.g. "What is your name?" "Well, sometimes when people ask me that 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, I think it's a little weird to have the same name as two of my other names, but the fact that I like it, is a good thing... but yeah, it's Tom."
• Clanging
  Clanging
  In psychology and psychiatry, clanging or clang association refers to a mode of speech and logical association to two or more words primarily based upon word sounds when no logical association between the words exists. For example, rhyming or alliteration may lead to the appearance of logical...
  
  – Sounds, rather than meaningful relationships, appear to govern words or topics. Excessive rhyming, and/or alliteration. e.g. "Many moldy mushrooms merge out of the mildewy mud on Mondays." "I heard the bell. Well, hell, then I fell."
• Derailment
  Derailment (thought disorder)
  In psychiatry, derailment refers to a pattern of discourse that is a sequence of unrelated or only remotely related ideas. The frame of reference often changes from one sentence to the next...
  
  (also Loose Association and Knight's Move thinking) – Ideas slip off the topic's track on to another which is obliquely related or unrelated. e.g. "The next day when I'd be going out you know, I took control, like uh, I put bleach on my hair in California."
• Distractible speech – During mid speech, the subject is changed in response to a stimulus. e.g. "Then I left San Francisco and moved to... where did you get that tie?"
• Echolalia
  Echolalia
  Echolalia is the automatic repetition of vocalizations made by another person. It is closely related to echopraxia, the automatic repetition of movements made by another person....
  
  – Echoing of one's or other people's speech that may only be committed once, or may be continuous in repetition. This may involve repeating only the last few words or last word of the examiner's sentences. This can be a symptom of Tourette's Syndrome. e.g. "What would you like for dinner?", "That's a good question. That's a good question. That's a good question. That's a good question."
• Evasive Interaction – Attempts to express ideas and/or feelings about another individual come out as evasive or in a diluted form, e.g.: "I... er ah... you are uh... I think you have... uh-- acceptable erm... uh... hair."
• Flight of Ideas – A sequence of loose associations or extreme tangentiality where the speaker goes quickly from one idea to another seemingly unrelated idea. To the listener, the ideas seem unrelated and do not seem to repeat. Often pressured speech is also present. e.g. "I own five cigars. I've been to Havana. She rose out of the water, in a bikini."
• Illogicality – Conclusions are reached that do not follow logically (non-sequiturs or faulty inferences). e.g. "Do you think this will fit in the box?" draws a reply like "Well duh; it's brown, isn't it?"
• Incoherence (word salad
  Word salad (mental health)
  In the mental health field, schizophasia, commonly referred to as word salad, is confused, and often repetitious, language that is symptomatic of various mental illnesses....
  
  ) – Speech that is unintelligible because, though the individual words are real words, the manner in which they are strung together results in incoherent gibberish, e.g. the question "Why do people comb their hair?" elicits a response like "Because it makes a twirl in life, my box is broken help me blue elephant. Isn't lettuce brave? I like electrons, hello."
• Loss of goal – Failure to follow a train of thought
  Train of thought
  The train of thought, stream of thought, trail of thought, or chain of thought refers to the interconnection in the sequence of ideas expressed during a connected discourse or thought, as well as the sequence itself, especially in discussion how this sequence leads from one idea to another.When a...
  
   to a natural conclusion. e.g. "Why does my computer keep crashing?", "Well, you live in a stucco house, so the pair of scissors needs to be in another drawer."
• Neologisms – New word formations. These may also involve elisions of two words that are similar in meaning or in sound. e.g. "I got so angry I picked up a dish and threw it at the geshinker."
• Perseveration
  Perseveration
  Perseveration is the repetition of a particular response, such as a word, phrase, or gesture, despite the absence or cessation of a stimulus, usually caused by brain injury or other organic disorder. If an issue has been fully explored and discussed to a point of resolution, it is not uncommon for...
  
  – Persistent repetition of words or ideas. e.g. "It's great to be here in Nevada
  Nevada
  Nevada is a state in the western, mountain west, and southwestern regions of the United States. With an area of and a population of about 2.7 million, it is the 7th-largest and 35th-most populous state. Over two-thirds of Nevada's people live in the Las Vegas metropolitan area, which contains its...
  
  , Nevada, Nevada, Nevada, Nevada." This may also involve repeatedly giving the same answer to different questions. e.g. "Is your name Mary?" "Yes." "Are you in the hospital?" "Yes." "Are you a table?" "Yes." Perseveration can include palilalia
  Palilalia
  Palilalia is the repetition or echoing of one's own spoken words. It can be a complex tic, like echolalia and coprolalia and may sound like stuttering; all can be symptoms of Tourette syndrome, obsessive–compulsive disorder, or autism...
  
   and logoclonia and is often an indication of organic brain disease such as Parkinson's.
• Phonemic paraphasia – Mispronunciation; syllables out of sequence. e.g. "I slipped on the lice and broke my arm."
• Pressure of speech – An increase in the amount of spontaneous speech compared to what is considered customary. This may also include an increase in the rate of speech. Alternatively it may be difficult to interrupt the speaker; the speaker may continue speaking even when a direct question is asked.
• Self-reference
  Self-reference
  Self-reference occurs in natural or formal languages when a sentence or formula refers to itself. The reference may be expressed either directly—through some intermediate sentence or formula—or by means of some encoding...
  
  – Patient repeatedly and inappropriately refers back to self. e.g. "What's the time?", "It's 7 o'clock. That's my problem."
• Semantic paraphasia – Substitution of inappropriate word. e.g. "I slipped on the coat, on the ice I mean, and broke my book."
• Stilted speech – Speech excessively stilted and formal. e.g. "The attorney comported himself indecorously."
• Tangentiality – Replying to questions in an oblique, tangential or irrelevant manner. e.g.:

Q: "What city are you from?"

A: "Well, that's a hard question. I'm from Iowa. I really don't know where my relatives came from, so I don't know if I'm Irish or French."

• Word approximations – Old words used in a new and unconventional way. e.g. "His boss was a seeover."

Diagnosis

The concept of thought disorder has been criticized as being based on circular or incoherent definitions. For example, thought disorder is inferred from disordered speech, however it is assumed that disordered speech arises because of disordered thought. Similarly the definition of 'Incoherence' (word salad) is that speech is incoherent.

Furthermore, although thought disorder is typically associated with psychosis

Psychosis

Psychosis means abnormal condition of the mind, and is a generic psychiatric term for a mental state often described as involving a "loss of contact with reality"...

, similar phenomena can appear in different disorders, potentially leading to misdiagnosis—for example, in the case of incomplete yet potentially fruitful thought processes.

It has been suggested that individuals with autism spectrum disorders (ASD) display language disturbances like those found in schizophrenia

Schizophrenia

Schizophrenia is a mental disorder characterized by a disintegration of thought processes and of emotional responsiveness. It most commonly manifests itself as auditory hallucinations, paranoid or bizarre delusions, or disorganized speech and thinking, and it is accompanied by significant social...

. A 2008 study found that children and adolescents with ASD showed significantly more illogical thinking and loose associations than control subjects. The illogical thinking was related to cognitive functioning and executive control; the loose associations were related to communication symptoms and to parent reports of stress and anxiety.