There are two main classifications of psychiatric disorders in current use: • the American Psychiatric Association’s Diagnostic and Statistical Manual (4th edition), or DSM-IV • the World Health Organization’s International Classification of Disease (10th edition), known as ICD-10. The two systems are similar; here we use the ICD-10 classification (Box 10.1). Psychiatric assessment differs from a standard medical assessment in the following ways: • There is greater emphasis on the history. • It includes a systematic examination of the patient’s thinking, emotion and behaviour (mental state). • It commonly includes the routine interviewing of an informant (usually a relative or friend who knows the patient), especially when the illness affects the patient’s ability to give an accurate history. • Memory. Registration of memories is tested by asking the patient to repeat simple new information, such as a name and address, immediately after hearing it. Short-term memory is assessed by asking him or her to repeat it after an interval of 1–2 minutes, during which time the patient’s attention should be diverted elsewhere. Long-term memory is assessed by gauging the recall of previous events. • Concentration. Serial 7s is a test in which the patient is asked to subtract 7 from 100 and then 7 from the answer, and so on. • Orientation. This is assessed by asking the patient about place – his or her exact location; time – what day, date, month and year it is now; and person – details of personal identity, such as name, date of birth, marital status and address. • Intellectual ability. This can be gauged from the history of the patient’s educational background and attainments but can also be assessed during the interview from the patient’s speech, vocabulary and grasp of the interviewer’s questions. Anxiety may be transient, persistent, episodic or limited to specific situations. The symptoms of anxiety are both psychological and somatic (Box 10.5). The differential diagnosis of anxiety is shown in Box 10.6. Most anxiety is part of a transient adjustment to stressful events: adjustment disorders (p. 242). Other more persistent forms of anxiety are described in detail on page 242. Anxiety may occasionally be a manifestation of a medical condition such as thyrotoxicosis (see Box 10.6). Depressive disorder must be differentiated from an adjustment disorder with depressed mood (p. 242). Adjustment disorders are common, self-limiting reactions to adversity, including physical illness, which are transient and require only general support. Depressive disorders (p. 243) are characterised by a more severe and persistent disturbance of mood and require specific treatment. In some cases, depression may occur as a result of a direct effect of a medical condition or its treatment on the brain, when it is referred to as an ‘organic mood disorder’ (Box 10.8). Patients with MUS may receive a medical diagnosis of a so-called functional somatic syndrome, such as irritable bowel syndrome (Box 10.10), and may also merit a psychiatric diagnosis on the basis of the same symptoms. The most frequent psychiatric diagnoses associated with MUS are anxiety or depressive disorders. When these are absent, a diagnosis of somatoform disorder may be appropriate (Box 10.11). Various types of delusion are identified on the basis of their content. They may be: • persecutory, such as a conviction that others are out to get me • hypochondriacal, such as an unfounded conviction that one has cancer • grandiose, such as a belief that one has special powers or status • nihilistic, e.g. ‘My head is missing’, ‘I have no body’, ‘I am dead’. Delusions should be differentiated from over-valued ideas, which are strongly held but not fixed. Disturbed and aggressive behaviour is common in general hospitals, especially in emergency departments. Most behavioural disturbance arises not from medical or psychiatric illness, but from alcohol intoxication, reaction to the situation and personality characteristics. The key principles of management are, first, to establish control of the situation rapidly and thereby ensure the safety of the patient and others, and, second, to assess the cause of the disturbance in order to remedy it. Establishing control requires the presence of an adequate number of trained staff, an appropriate physical environment and sometimes sedation (Fig. 10.2). Hospital security staff and sometimes the assistance of the police may be required. In all cases, the staff approach is important; a calm, non-threatening manner expressing understanding of the patient’s concerns is often all that is required to defuse potential aggression (Box 10.12). • organic disorders such as delirium, dementia, and focal deficits secondary to brain lesions • psychiatric disorders such as depressive pseudo-dementia and dissociative disorder Further investigation will usually be needed to identify the specific causes of any cognitive impairment identified (see Box 10.32, p. 250, and p. 209). Misuse of alcohol is a major problem worldwide. It presents in a multitude of ways, which are discussed further on page 252 and in Box 10.35 (p. 253). In many cases, the link to alcohol will be all too obvious; in others, it may not be. Denial and concealment of alcohol intake are common. In the assessment of alcohol intake, the patient should be asked to describe a typical week’s drinking, quantified in terms of units of alcohol (1 unit contains approximately 8 g alcohol and is the equivalent of half a pint of beer, a single measure of spirits or a small glass of wine). Drinking becomes hazardous at levels above 21 units weekly for men and 14 units weekly for women. The history from the patient may need corroboration by the GP, earlier medical records and family members. The mean cell volume (MCV) and γ-glutamyl transferase (GGT) may be raised, but are abnormal in only half of problem drinkers; consequently, normal results on these tests do not exclude an alcohol problem. When abnormal, these measures may be helpful in challenging denial and monitoring treatment response. The prevention and management of alcohol-related problems are discussed on page 253.
Medical psychiatry
Classification of psychiatric disorders
Diagnosing psychiatric disorders
Mental state examination
Cognitive function
Presenting problems in psychiatric illness
Anxiety symptoms
Depressed mood
Differential diagnosis
Medically unexplained somatic symptoms
Delusions and hallucinations
Delusions
Disturbed and aggressive behaviour
Confusion
Differential diagnosis
Alcohol misuse
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