It’s psychopathology time again, here on planet Frontier Psychiatrist.  It’s been in the family as my brother recently  attempted the Fourteen Peaks Challenge will testify.  This is his story:

‘In June 2008 my friends and me decided to attempt the 14 Peaks Challenge. This involves scaling all 14 peaks in Wales which are in excess of 3000 ft and is a very long walk, taking up to 24 hours to complete.

After driving up from London, our party started walking at about 2am.  By around 4pm the next day I was starting to experience some quite peculiar visual effects.  Every time I looked at a stone, I could immediately pick out an image of a face or the shape of an animal (typically a crocodile).  Whereas normally it would take a conscious effort to see a pattern in an inert object, the comparisons were coming to me thick and fast.  At one point I picked up a piece of quartz convinced that it had the shape of an ancient Egyptian head.

I gave up the walk at around 6pm, having not slept for around 36 hours.  My tougher companions pushed on and walked for another 10 hours.  Their visual hallucinations apparently became much more vivid than mine with objects becoming actual animals and not just resembling them.’

Depending on your bent in life, this either sounds pretty cool, or pretty scary.  Plenty of people pay good money for similar nights out.

Psychiatrists have spent a lot of time classifying abnormal experiences; psychopathology is the study of this.  This is a big subject, so I’m going to gloss over a few bits.

As human beings we have a number of senses and sense organs and the brain interprets the sensory input from these.  Thus, perception consists of two parts - sensation (visual, auditory, tactile, gustatory, olfactory, kinasthetic and proprioceptive) and interpretation (the cognitive element).

But things can go wrong:

1. The stimulus can be perceived as the corresponding object, but not accurately.  For example an object could be perceived as being the wrong size; this is called micropsia or macropsia.

2. The stimulus is perceived as an object, but not corresponding to the source.  That is to say, both the stimulus and object are present, but different from each other.  This is an illusion

3. There is no stimulus, but a perception occurs.  This is a hallucination. 

4. There is a stimulus, but no perception occurs.  This is a negative hallucination.

So, my brother wasn’t hallucinating, but was seeing an illusion.  There are three major types of illusions:

1. Affect illusions:  here the person’s emotional state leads to misperceptions - perhaps being scared leads to the incorrect interpretation of a shadow.

2. Pareidolia: here a person perceives formed objects from ambiguous stimuli, for example seeing Elvis’s head in a cloud. 

3. Completion illusion: here, due to inattention, an incomplete object is perceived as complete.  For example, CCOK might be read as COOK.

Hallucinations

Hallucinations have several important qualities.  They take place in the same space and at the same time as other real perceptions - this is different from a fantasy or imagery, which take place in subjective space, or a dream, which has no real component;  they are experienced as sensations and have all the qualities of a real object from which they are indistinguishable. They are involuntary, so unlike imagery, they are not under conscious control.

Hallucinations can occur in any modality and there are many different types:

Elementary hallucinations are the simplest kind and they are unstructured hallucinations and bear no relation to anything in the natural world.  An example of this is whirring noises in the auditory modality.  In the visual modality, a person with elementary hallucinations might see multicoloured spots.  

 

Auditory hallucinations often occur with psychiatric illness, and auditory hallucinations of voices are one of the first rank symptoms of schizophrenia.  Visual hallucinations on the other hand are much more common with organic illness and are very uncommon in schizophrenia.  Organic causes for hallucinations include occipital lobe tumours, post concussional states, hepatic failure and dementia.  

Elderly patients with normal consciousness and no brain pathology, but with reduced visual acuity due to ocular problems experience vivid, distinct formed hallucinations, often of men wearing hats.  This is called Charles Bonnet syndrome.  Lilliputian hallucinations involve seeing tiny people or animals.  These can occur with alcohol withdrawal.  

Other sorts of hallucinations: 

Autoscopic hallucinations are the experience of seeing oneself.  This is different from an ‘out of body’ experience, as with the latter the person sees the world and his own body from a vantage point that is other than his physical body.  In autoscopy, the person ‘remains’ in their own body.

Extracampine hallucinations occur outside the field of normal perception.  An example of this would be hearing someone discussing you down the shops which are a mile away.   

Functional Hallucinations is where an external stimulus provokes hallucination, but both hallucination and stimulus are in the same modality but individually perceived.  An example of this would be hearing a voice when the tap is running.  On the other hand, Reflex hallucinations are when hallucinations in one modality are provoked by a stimulus in another modality.  An example would be seeing a elf whenever listening to music.

Formication is a type of haptic hallucination where there is the sensation of animals crawling under the skin.  This is seen in cocaine intoxication.  A character in the beginning of the film ‘A Scanner Darkly’ has a similar problem.

NB:

A pseudohallucination is like a hallucination, but lacks the quality of a perception.  It is a form of vivid imagery.  If someone feels that they are hearing voices in their head, this is a pseudohallucination as it does not have the same qualities as a normal perception. 

Synaesthesia is the perceiving of a stimulus in one modality in a different modality, for example, ‘hearing’ the colour red.  This can happen on taking LSD

Hypnagogic and hypnopompic hallucinations are hallucinations on falling asleep and waking up, respectively.  They may be normal phenomena and are particularly seen in narcolepsy 

Further reading:

Symptoms of the Mind by Femi Oyebode (Buy from Waterstones Amazon)

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Just like when a physician sees a patient and looks for signs of physical illness, when a psychiatrist meets a patient they are looking for signs of psychiatric illness.  This is important because when people are suffering a deterioration in their mental health, they often describe similar experiences and these signs of mental illness are referred to as psychopathology.  When different psychopathological signs are identified and grouped together they can lead to the formation of a psychiatric diagnosis.

One of the most interesting psychopathology signs is formal thought disorder (FTD) which refers to the sort of disorganised speech which is a manifestation of psychosis. 

When people are describing a patient’s mental state they often write ‘no FTD’ when they wish to convey that the patient is coherent and can make themselves understood.  It’s a little bit more subtle than that; if a patient is intoxicated or delirious they will be incoherent but they will not necessarily be thought disordered.  Thought disorder refers to a particular set of language errors which are seen in psychosis. 

The name is rather strange.  Although it is called ‘formal thought disorder’ it actually refers to what a patient is saying.  The name is historical as when disorders of speech due to psychiatric illness were first being described (Bleuler, amongst others, was important in this), it was felt that disorders of thought form (disorganised speech) and content (delusions) should be considered separately.  Formal thought disorder therefore is a disorder of speech rather than content*.  

Normal human thinking has three characteristics

1. Content: what is being thought about - this would include delusions and obsessional thoughts

2. Form: in what manner, or shape, is the the thought about; abnormalities of the way thoughts are linked together

3. Stream or flow: how it is being thought about - the amount and speed of thinking

Different elements of formal thought disorder have been described. With his early work, Bleuler considered FTD to be when there was a loosening of associations which lead to fragmentary ideas being connected illogically.  This is seen clearly in the picture above.  Confusingly though, there appears to be no consensus about exactly what can be included formal thought disorder; it appears that most people would now use the term ‘thought disorder’ which refers to both errors of form and stream. Content is still considered separately.  

 

Disorder of stream of thought 

(I’ve split up these into disorder of thought form and stream, but several could be argued both ways)

Flight of ideas is when the content of speech moves quickly from one idea to another so that one train of thought is not carried to completion before another takes its place.  The normal logical sequence of ideas is generally preserved although ideas may be linked by distracting cues in the surroundings and from distractions from the words that have been spoken.  These verbal distractions may be of three kinds: clang associations, puns and rhymes.

Retardation of thinking is often seen in depression, the train of thought is slowed down, although still goal directed.  The opposite is pressure of speech and this is often seen in mania.

Peseveration is the persistent and inappropriate repetition of the same thoughts.  In reply to a question a person may give the correct answer to the first but continue to give the same answer inappropriately to subsequent questions.  This is especially seen in ‘organic’ brain disorders like dementia.

 

Disorders of thought form:

Overinclusion refers to a widening of the boundaries of concepts such that things are grouped together that are not often closely connected.

Loosening of associations denotes a loss of the normal structure of thinking.  The patient’s discourse seems muddled and illogical and does not become clearer with further questioning; there is a lack of general clarity, and the interviewer has the experience that the more he/she tries to clarify the patient’s thinking the less it is understood.  Loosening of associations occurs mostly in schizophrenia

Three kinds of loosening of association have been described:

Knight’s move thinking or derailment where there are odd tangential associations between ideas. 

Talking past the point (= vorbeireden) where the patient seems to get close to the point of discussion, but skirts around it and never actually reaches it

Verbigeration (= word salad = schizophasia = paraphrasia) where speech is reduced to a senseless repetition of sounds and phrases  (this is more of a disorder of thought form)

Circumstantiality is where thinking proceeds slowly with many unnecessary details and digressions, before returning to the point.  This is seen in epilepsy, learning difficulties and obsessional personalities 

Neologisms are words and phrases invented by the patient or a new meaning to a known word

Metonyms are word approximations e.g. paperskate for pen

Derailment (aka entgleisen) is where there is a change in the track of thoughts.  There is perserved, but misdirected determining of tendency/goal of thought)

With drivelling there is a disordered intermixture of the constituent parts of one complex thought

Fusion is where various thoughts are fused together, leading to a loss of goal direction.

Omission is where a thought or part of a thought it is senselessly omitted

Substitution is where one thought fills the gap for another appropriate more ‘fitting-in’ thought.

Concrete thinking is seen as a literalness of expression and understanding, with failed abstraction.  Can be tested by the use of proverbs.

Thought block  refers to the sudden arrest in the flow of thoughts.  The previous idea may then be taken up again or replaced by another thought.

 

As you can tell this is a big subject and I haven’t got onto the historical attempts to characterize schizophrenic thought processes (by Kraepelin, Bleuler, Goldstein, Cameron and Schneider) or the linguistic classification of speech abnormalities in psychosis. 

Further reading

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

*Quite why they choose this name though it unclear to me, and if anyone else can shed more light on it I would be grateful. 

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