What are Disorders of Thought?
There are a number of different types of thought disturbance.
Disorder of the stream of thought
This refers to disturbances to the speed of thought processing as well as the amount of thought.
- Poverty of thought - often a feature of depressive disorders and schizophrenia, this refers to a lack of thought and poor variety or richness.
- Pressure of thought - this may occur in manic episodes and schizophrenia. There is great variety and abundance of thought.
- Thought blocking - this is where thoughts are interrupted and the person reports an emptying of their mind. It is common in schizophrenia. It happens suddenly and often.
Disorder of form of thought - these are apparent through a person's speech or writing.
- Perseverance - this is continual repetition of the same thoughts which are inappropriate e.g. providing the same answer to a range of different questions.
- Flight of ideas - this is where a person shifts from one thought to another without completing the previous one. It occurs in manic episodes. There is usually a logical sequence of ideas it's just that none are completed.
- Loosening of associations - this is where thinking becomes unstructured as evidenced through speech which appears disorganised and confused. Derailment refers to changing topics in mid-sentence to a completely unrelated topic (unlike flight of ideas where there is evidence of a logical sequence. Verbigeration refers to repetition of speech sounds or words which make no sense. When extreme it is called 'word salad'. Talking past the point is where the person never gets to the point although they always seem like they are going to.
Consider:
- Neologisms - these are words made up by a patient.
- Over-inclusion - this is grouping things together which are not connected.
Delusions
This is a firmly held irrational belief which is maintained even when evidence to the contrary is presented. Delusions may be of primary onset where they seem to appear from nowhere, or they may have secondary onset where they are used to explain another abnormal experience. Delusions are considered to be complete but there are also partial delusions whereby the person may have some doubts about their delusions from the beginning or where they begin to doubt them during treatment.
Delusional mood refers to the mood from which a delusion arises. There is an emotional reaction when an individual experiences a delusion for the first time. Sometimes a person may attribute meaning to a perception in what is called delusional perception. Delusional memory refers to attaching new meanings to past memories. Occasionally delusions may be shared, particularly where one person lives with another. This is known as a 'folie a deux'. Many different types of delusion are recognised with regards to various themes and some notable ones are as follows:
- Delusions of reference - this is where the person believes that particular people, objects or events are associated with them e.g. commentary they hear on the TV relates specifically to them and is either a message to them or a message informing others about them.
- Delusions of persecution - these usually concern the belief that an organisation or individual is attempting to undermine the person or inflict some sort of wrongdoing on them.
- Delusions of grandeur - these refer to erroneous beliefs that the individual is of great importance e.g. of royal descent, extremely intelligent or wealthy, or having an extraordinary talent.
- Delusions of jealousy - these are more common in men and usually involve doubts about a partner's fidelity. They can culminate in aggressive behaviour towards the person thought to be unfaithful. The person may examine clothing and follow their partner to try and uncover evidence of indiscretions. Even where evidence cannot be found to support their delusion, they will continue to look for it.
- Delusions of control - this is where someone believes that an outside agency has control over their thoughts and behaviours. This is sometimes called delusions of mind being read.
- Delusions of possession of thoughts - these are most usually associated with schizophrenia. They include delusions of thought insertion whereby the individual believes that someone is implanting thoughts into them, delusions of thought withdrawal where an individual believes that their thoughts are being extracted from their minds, and delusions of thought broadcasting where the person believes that their thoughts are being made available to others through telepathy, radio waves or some other means.
- Delusions of guilt and worthlessness - these are associated with beliefs such as a minor misdemeanour will bring about shame on the person's family. They are more likely to be present in depressive disorders
- Delusions of religion - these should be distinguished from normal religious beliefs held by members of a particular religious group. They are not as common in Western society as they were when religion played a greater role in everyday life.
- Delusions of nihilism - these are often associated with depressive disorders. It is where the individual believes that something terrible is going to happen or has happened which involves death or non-existence. Common themes include the world is about to end.
- Cotard's delusion - this is a form of nihilistic delusion where the individual believes that they are dead. It is sometimes called 'walking corpse syndrome'.
- Delusions of hypochondria - also called somatic delusions, these are beliefs that a person has some form of physical illness even though all the evidence presented to them suggests otherwise.
- Sexual delusions - these involve themes about love and sex and are also sometimes classed as erotomania. They involve misplaced beliefs that someone is sexually attracted to or in love with the individual. Typically the focus of the delusion is someone who is inaccessible and with whom they have had no previous contact. They may attempt to contact the person through phone calls, emails or letters and sometimes may resort to stalking them.
Intrusive thoughts
These are thoughts which interfere with thinking. They can be associated with specific conditions e.g. substance abuse disorders where thinking is interrupted by cravings for a substance following periods of withdrawal. They are also associated with anxiety and depressive disorders because they often trigger an emotional response. These thoughts can often be controlled using techniques to stop them or by using distraction.
Overvalued Ideas
These are not the same as delusions or obsessions. They are beliefs which feature heavily in an individual's life and which can influence their decision-making, but usually there is an understandable explanation for them even though the beliefs may be faulty. They are present in anorexia nervosa where the person believes that they are overweight and look fat despite evidence to the contrary.
Obsessive symptoms
Obsessions are impulses, images or thoughts which keep returning even though an individual tries to stop them. The person who experiences obsessions feels that they are constantly battling to prevent them. They also believe that thinking about something will increase the likelihood of it happening. Unlike delusions, the person knows that the thoughts are of their own making and that they are not true and pointless. If they are unable to rid themselves of the obsessions, over time they may show less resistance to them. Although obsessions can concern any theme some commonly occurring ones include:
- Orderliness e.g. thoughts about arranging objects symmetrically or in an exact way
- Contamination e.g. thoughts concerning spreading disease to others
- Illness (somatic) e.g. thoughts about developing terminal cancer
- Aggression e.g. thoughts about hitting people
- Hoarding e.g. thoughts concerning not throwing anything away
- Pathological doubt e.g. thoughts that something has not been done
- Religion e.g. thoughts concerning doubts over whether sins have been confessed properly
- Sex e.g. thoughts concerning shameful sexual activities.
A number of different types of obsession have been identified:
- Obsessive thoughts - these are intrusive phrases or words which upset the person. For instance, a straight male may keep thinking of homosexual acts or words associated with them.
- Obsessive doubts - these involve a person recurrently doubting that they have undertaken a particular action e.g. unplugging electrical items and turning the switch off at the wall because the person is concerned over the risk of fire. The concern is recognised as being excessive.
- Obsessive ruminations - these are recurrent themes which interfere with a person's thinking. They are more convolute than obsessive thoughts.
- Obsessive impulses - these are strong urges to carry out a particular behaviour which is usually aggressive, risky or demeaning to them in some way. They don't want to do it and they resist acting on the impulse. For instance, a man has obsessive impulses about going to work dressed in his wife's clothes.
- Obsessive phobias - these concern avoidance and anxiety. An obsessive impulse about cross-dressing may lead a man to avoid women's clothing.
Compulsions
These are behaviours which are conducted in a repetitive way. Like obsessions, the individual tries to resist them and they are acknowledged as being pointless. They serve no pleasure and are recognised as being excessive. Often they are associated with an obsession e.g. to deal with obsessions concerning contamination an individual may wash their hands repeatedly. Sometimes a compulsion may be of the form that if a particular behaviour is not carried out in a specific way according to rigid rules then harm may come to others. Often obsessions and compulsive acts take up a lot of time and slow people down. Sometimes slowness itself can be a primary feature. Some common compulsions include:
- Checking e.g. that electrical equipment is switched off at the wall and unplugged
- Cleaning e.g. repeatedly washing hands or cleaning door handles
- Counting e.g. counting in fives, and then counting gain to check that is was done properly
- Dressing e.g. arranging clothes in a specific pile and dressing in a stereotyped way
