The main form of abnormal belief is the delusion (Information box 19.1). Delusions can be:
PRIMARY or autochthonous, i.e. they appear suddenly and with full conviction but without any preceding or related mental events. For example, a patient on being offered a cup of tea suddenly believes that this indicates that the Russians have landed at Dover.
SECONDARY, i.e. derived from some preceding morbid experience, such as a depressed mood or an auditory hallucination.
Delusions are classified according to their content, and include persecutory delusions (also called paranoid delusions), delusions of reference, guilt, worthlessness or nihilism, religious delusions, and delusions of grandeur, jealousy or control. These are further defined when discussed in relation to specific conditions.
Particular delusions concerning thought control can occur. Patients who have delusions of thought insertion believe that some of their thoughts are not their own but have been implanted by some outside force or agency.
The same or other patients may believe that thoughts are taken out of their minds by external forces or agencies (thought withdrawal), while in delusions of thought broadcasting patients believe that their unspoken thoughts are known to other people through radio, television, telepathy or in some other way. Feelings and actions may also be interpreted by the individual as being under the influence or control of some external, usually alien, power. Such passivity experiences, occurring in the absence of clear-cut brain diseases, are regarded as diagnostic of schizophrenia. Patients may merely assert that their behaviour is controlled from without and may be unable to give any further explanation. This is usually described as an experience of passivity. Patients may develop secondary delusions that explain this alien control as a result of witchcraft, hypnosis, radio waves, television-so-called delusion s of passivity. The disturbances of thought controldiscussed above are examples of passivity experiences involvi ng the thought processes.
Delusions should be distinguished from overvalued ideas, i.e. deeply held personal convictions that are understandable when the individual’s background is known. Ideas of reference that fall short of delusions are held by people who are particularly self-conscious. Such individuals cannot help feeling that people take particular notice of them in p ublic places, pass comment about themand/or observe things about them that they would prefer were ignored. Such a feeling is not delusional in that individuals who experience it realize that it originates within themselves and that they are no more noticeable or noteworthy than anyone else, but nevertheless cannot dismiss the feeling.
Abnormal experiences referred to the environment. body or self
Illusions are misperceptions of external stimuli and are most likely to occur when the general level of sensory stimulation is reduced. Hallucinations (Information box 19.2) a re perceptions that are experienced in the absence of any external stimulus to the sense organs in the outside world (and are not within one’s mind as in imagery). Normal people occasionally experience hallucinations, mainly auditory in type, particularly when tired and during the transition between sleeping and waking.
Hallucinations can be elementary (e.g. bangs, whistles) or complex (e.g. faces, voices, music), and may be auditory, visual, tactile, gustatory, olfactory or of deep sensation. A change in self-awareness such that the person concerned feels unreal is termed depersonalization. In this state the person feels detached or remote from selfexperience and unable to feel emotion. The individual is aware of the subjective nature of this alteration. The feeling that the external environment has become unreal
and/or remote is term ed derealization. Both thesephenomena occur in healthy people when they are tired, after sensory deprivation and during the use of hallucinogenic drugs, and also occur in certain conditions such
as anxiety, depression, schizophrenia and temporal lobe epilepsy.
There are four processes involved in normal memory:
REGISTRATION -the ability to add new material to the existing memory stores
RETENTION -the ability to retain the memory
RECALL -the ability to bring it back into awareness
RECOGNITION -the feeling of familiarity indicating that a particular person, event or object has been encountered before
Some patients describe the recognition of a situation, person or event as having been encountered before when it is in fact novel- the so-called deja vu experience, whereas others report the reverse experience (jamais vu) when there is failure to recognize a situation, person or event that has been encountered before. Deja vu experiences occur in healthy people as well as in anxiety states. Both types of experience can occur in epilepsy.
Patients with Wernicke-Korsakoff syndrome, who have extreme difficulty in remembering recent and past events, sometimes report remembering past events that have not actually taken place; this is known as confabulation. Failure of memory is termed amnesia.
Consciousness can be defined as the awareness of the self and the environment. Attention, concentration and memory are impaired and orientation is disturbed in any condition in which a disorder of consciousness occurs.
These are a series of subconscious mental processes. The individual is unaware of employing them although may become aware of such motives through self-analysis or demonstration by another person. The defence mechanisms described below are amongst the commonest used and are useful in understanding many aspects of behaviour.
REPRESSION is the exclusion from awareness of memories, emotions and/or impulses that would cause anxiety and distress if allowed to enter consciousness.
DENIAL, a related concept, is believed to be employed when patients behave as though unaware of something that they might reasonably be expected to know. One example would be a patient who, despite being told that a close relative has died, continues to behave as though the relative were still alive.
REGRESSION is the unconscious adoption of patterns of behaviour appropriate to an earlier stage of development. It is often seen in ill people who become childlike and highly dependent in relation to their doctor and nursing care.
PROJECTION involves the unconscious attribution to another person of thoughts or feelings that are in fact one’s own.
REACTION FORMATION refers to the unconscious adoption of behaviour opposite to that which reflects the individual’s true feelings and intentions.
DISPLACEMENT involves the transferring of emotion from a situation or object with which it is properly associated to another that gives less distress.
RATI0NALIZATI 0N refers to the unconscious process whereby a false but acceptable explanation is provided for behaviour that in fact has other, much less acceptable, origins
SUBLIMATION refers to the unconscious diversion of unacceptable outlets into acceptable outlets.
IDENTIFICATION refers to the unconscious process of taking on some of the characteristics or behaviours of another person, often to reduce the pain of separation or loss.
Summary of symptoms and signs
When the full psychiatric history is taken and the patient’s mental state has been assessed, it is important to provide a concise assessment of the case which is termed a formulation. In addition to summarizing the essential features, the formulation includes a differential diagnosis, a discussion of possible causal factors, identification of outstanding issues to be clarified, an outline of further investigations needed and concludes with a concise plan of treatment and a statement of the likely prognosis.
CAUSES OF A PSYCHIATRIC DISORDER
A single psychiatric disorder may result from several causes.
These are factors, often operating from early life, that determine a person’s vulnerability to psychological distress. Such causes include:
• Genetic endowment
• Environment in utero
• Childhood trauma
There is evidence for a strong genetic factor in the psychoses, and a weaker genetic factor in the neurotic disorders. Intrauterine disturbances may result in minor organic damage to the brain and central nervous system (eNS), which in turn may render the individual liable to develop a serious mental disorder in later life in responseto partic ular kinds of stress.
Personality results from the interaction of genetic endowment, uterine development, early childhood experience and various physical, psychological and social influences manifesting themselves up to and including adolescence. Certain personalities are believed to be particularly prone to develop certain disorders. For example, individuals who manifest certain obsessional traits as part of their personality have an increased risk of developing depressive and obsessional illnesses, while anxious, apprehensive individuals are prone to develop a variety of
neurotic disorders. When taking the history, particular care should be taken to assess whether the individual’s personality was well developed and mature prior to the development of the illness, as this will be a major factor in determining the outcome of treatment and the prognosis.
These are factors that occur shortly before the onset of a disorder and that appear to have caused it. They may be physical, psychological or social in nature. Whether they produce a disorder depends partly on their severity and partly on the presence of predisposing factors.
PHYSICAL precipitating factors include physical diseases (e.g. hypothyroidism, tumours, metabolic disorders) or drugs (e.g. steroids, hypotensives, alcohol).
PSYCHOLOGICAL factors include loss of self-esteem due to a setback or misfortune such as marital infidelity or financial disaster.
SOCIAL factors include moving house, job difficulties and family disturbances.
Occasionally, the same factor can act in more than one way. A head injury can induce psychological disturbances either through physical changes in the central nervous system or through the stress it provokes in the individual, while marital breakdown may lead to overindulgence in alcohol with secondary impairment of mental processes an d psychiatric illness.
These are factors that prolong the course of a disorder after it has occurred. For example, some psychiatric disorders lead to secondary demoralization. A medical student who suffers a depressive illness may well find it difficult to accept the diagnosis, may feel weak and flawed, and may withdraw from social activities. Such a response could prolong the original disorder.