DEFINITION Personality disorders involve deeply ingrained maladaptive patterns of behaviour, which cause harm to the subject and/or to other people. These disorders are generally recognizable by the time of adolescence, and continue through most or all of adult life.

The older term ìpsychopathyî may be used for any personality disorder, but is usually reserved for the ìantisocialî type.

Great caution must be exercised before the diagnosis is given, as it can have pejorative implications, and can lead to the patient being rejected from services as untreatable.

Indeed, it has been observed, only half jokingly, that the only people who do not have a personality disorder, are those without a personality. This makes the important point that all of us have personality traits, which could be maladaptive or counterproductive, in certain circumstances.

With increasing clinical experience, one not infrequently encounters patients who have been given a diagnosis of personality disorder during a difficult phase in their lives, only to settle down again subsequently. To use psychological terms, the problem has in these patients turned out to be "state" not "trait".

CLASSIFICATION It is first necessary to discuss how ìnormalî personality may be classified. There are two general approaches, the ideographic and the nomothetic.

• ideographic theory views each person as a unique individual, with aspects of their personality which may not be possessed by anyone else. The structure of the personality may be different between individuals, even though similar traits may be present; the relative importance of such traits may also differ. This approach gives great weight to detailed appreciation of the individual history in case studies.

• nomothetic theory, by contrast, sees each person as possessing greater or lesser amounts of a number of personality traits, these traits being present to a greater or lesser extent in all members of the population. In other words, each personality is made up of a unique selection from a sort of a la carte menu of personality traits, each of which are assumed to have the same meaning or effect in each person.
  

This latter approach has been dominant in recent years, as it is clearly susceptible to a quantitative approach, with self-report personality questionnaires, structured interviews and factor analysis of the results thereof. For example, it has been suggested that a Five Factor Model (neuroticism, extraversion, openness, agreeableness, and conscientiousness) can account for much of the observed personality characteristics of different individuals, and that this may reflect a strong genetic aspect to such traits (1).

Although the evidence base for a nomothetic approach to understanding personality may continue to grow, it is counterintuitive (or just plain silly) to think that it will ever be able to account for the infinite variety of individual personality.

Use of personality measures such as the MMPI (Minnesota Multiphasic Personality Inventory) is claimed to give quantitative measure of aspects of personality. However, they are very time consuming, and their interpretation is constantly in development, with new subscales frequently suggested to measure specific attributes. Their use remains uncommon in UK clinical practice in psychiatry,

"THE PATIENT HAS TWO PDs!" The various types of personality disorder as described below overlap with each other and many individuals have traits characteristic of more than one type. If a patient satisfies criteria for more than one, it does not mean that they have ìtwo personality disordersî, in the sense of two separate conditions which are additive, and that they are therefore necessarily ìtwice as severeî.

CLASSIFICATION OF PDs: DSM vs ICD There is much common ground between the two classifications in how they deal with personality disorder, but also a small number of significant differences.

Probably the most significant difference is that DSM IV contains schizotypal personality disorder, though this does not appear in ICD.

• Schizotypal personality disorder is said to be characterised by ìideas of referenceÖ magical thinkingÖ unusual perceptual experiences, including bodily illusions.. odd thinking and speech .. suspiciousness or paranoid ideationî. It has been suggested that the category may serve to contain the excess of cases of schizophrenia previously diagnosed by US psychiatrists as against those from the UK and other countries (2). F21 schizotypal disorder does appear in the ICD10; the list of clinical features is very similar, but it is included within the same block as schizophrenia. Confusingly, ICD indicates ìevolution and course are usually those of a personality disorderî. In any event, the diagnosis is not frequently made in UK clinical practice; most clinicians would regarded it as a mild or prodromal form of schizophrenia, and would attempt standard management of that condition.

• By contrast, the DSM concept of borderline personality disorder (see below) has achieved clinical currency in the UK, even though it does not appear in ICD10.

• The DSM also contains narcissistic personality disorder, which overlaps with histrionic personality disorder on the one hand and with antisocial personality disorder on the other. It is not separately coded in ICD 10.

• The final main difference is that DSM groups the personality disorders into three clusters:

• Cluster A: odd-eccentric, including paranoid, schizoid and schizotypal personality disorder.
• Cluster B: dramatic-emotional-erratic, including antisocial, borderline, histrionic and narcissistic personality disorder.
• Cluster C: anxious-fearful, including avoidant, dependent, and obsessional compulsive personality disorder.

There is no comparable grouping in ICD 10, and this concept is not in my experience in widespread use in clinical practice.

TYPES OF PERSONALITY DISORDER The types of personality disorder described in ICD 10 will now be delineated. As will be appreciated, they do overlap.

• Paranoid personality disorder F60.0: in this condition, the subject appears touchy and oversensitive; they are suspicious of the motives of others and prone to the development of overvalued ideas including ideas of reference (Ch 8). They may be excessively self-reliant and self-isolatory, and often have queued with neighbours or officialdom. The symptoms for short of satisfying criteria for psychosis. However, some do go on to develop a psychiatric illness with paranoid symptoms, typically a paranoid psychosis or schizophrenia.

• Schizoid personality disorder F60.1: these subjects tend to be shy, reserved, introspective, emotionally cold and shunning close relationships. They are often eccentric ìwith preference for fantasy, solitary activities, and introspectionî. A small proportion develop schizophrenia.

• Dissocial (antisocial, sociopathic, psychopathic) personality disorder F60.2: showing repeated antisocial behaviour, not modified by experience or punishment. This type will be discussed in more detail below. There is an excess of males than females with this diagnosis.

• Emotionally unstable personality disorder F60.3: Subjects are emotionally unstable, and prone to excessive outbursts of anger or distress. The US equivalent is borderline personality disorder, and this term has come to be more frequently used. The essential concepts are the same however. The patient may engage in repeated acts of deliberate self harm, such as cutting or overdoses, or otherwise sabotage his or her own interests, for example, when they are on the point of getting a new job or starting a new relationship. There is an excess of females over males with this diagnosis.

• Histrionic personality disorder F60.4 These patients are prone to over-dramatization and transient emotional displays, particularly regarding relationships. They are described as self-self-centred, emotionally shallow, and with little concern for the feelings of others. It was formerly known as hysterical personality disorder.

• Anankastic (obsessive-compulsive) personality disorder F60.5: these subjects tend to be cautious, painstaking, perfectionistic and may show stubbornness with a lack of flexibility; they may do well in occupations requiring extreme attention to detail; conversely, they may be handicapped in forming intimate relationships, with all the give-and-take that this entails. Under stress, they may develop any neurotic reaction, characterised by depression or full-blown obsessive-compulsive disorder.

• Anxious [avoidant] personality disorder F60.6): as evident from the name, the subject is affected by chronic feelings of worry, apprehension and low-grade anxiety symptoms generally. They may avoid social interaction, being generally shy, and often compare themselves adversely with others, leading to low self-esteem. Under stress, these patients can develop a range of anxiety or depressive conditions.

• Dependent personality disorder F60.7: characterised by. ì.. pervasive passive reliance on other people to make one's major and minor life decisions, great fear of abandonment, feelings of helplessness and incompetence, passive compliance with the wishes of elders and others, and a weak response to the demands of daily life. Lack of vigour may show itself in the intellectual or emotional spheres; there is often a tendency to transfer responsibility to others.î A typical instance would be an individual of normal intelligence, but who fails to separate from the family, and lives a retired life at the parental home, perhaps not working, and often not presenting until the death of the parents.

Under F60.8 Other specific personality disorders, ICD gives the following headings, eccentric, "haltlose" (mixture of frontal lobe, antisocial and histrionic personality traits), immature, narcissistic, passive-aggressive and psychoneurotic, but supplies no further information about their characteristics.

In clinical practice, it is more important to make a clear diagnosis of personality disorder, based on the temporal and other characteristics, and then to describe the difficulties presented by the patient, than to sueeze the patient into one or more of these artifical "boxes". The types of personality disorder in the classifications are really only a guide, and the majority of patients have symptoms from more than one type of personality disorder, as described.

Multiple personality is a rare condition of dubious validity: it seems to develop in vulnerable individuals, called forth by the interest and attention which the concept may excite in the treating professionals.

EPIDEMIOLOGY A recent review indicates that the prevalence in the community is 10-13%, though obviously this depends on the definition used. Some forms (e.g. antisocial PD) are more common in men, with others (e.g. borderline PD) more common in women.

Antisocial PD has a prevalence of about 2-3% in the community, but as high as 78% in prison populations.

DIFFERENTIAL DIAGNOSIS

• ìNormalî personality: there is no fixed dividing line between the normal and disordered personality. Many of the personality traits mentioned above are only disadvantageous if present to extremes. Mild degrees may carry benefits in the right setting; for example, an anankastic personality may do well as a librarian, and a histrionic personality in the entertainment world. Personality disorder should only be diagnosed if the personality traits consistently impair well-being, personal relationships or work, or lead to dependence on drugs or alcohol.

• Learning disability The other main permanent feature of an individualís mental makeup is his level of intelligence. The DSM helpfully codes both personality disorder and learning disability on the same Axis II. It used to be customary to do psychological testing of intelligence for many psychiatric patients, but this is now unusual unless there is a definite indication. Hence it is important to remember that mild degrees of learning disability can easily be missed.

• Psychiatric illness: personality disorders are relatively permanent conditions, whereas psychiatric illnesses involve a potentially reversible change from the patientís usual function. In other words, it is the time course, which is crucial. Personality disorder, unlike mental illness, has no identifiable beginning. The distinction between personality disorder and psychiatric illness can be difficult, however, because:

• Organic brain disease often causes personality change.

TREATMENT By definition, personality disorders involve persistent characteristics which cannot easily or quickly be eradicated. However, it is wrong to assume that all these patients are untreatable: it may well be possible to contain or even modify undesirable personality traits and their ill-effects.

The principles of treatment include:

• consistent care, perhaps including:
• identified key worker or therapist
• written contract
• realistic goals- this may initially be harm minimisation only
• assessment of risk, to self and/or others
• proportionate response to manage risk
• may need mulitagency working (e.g. probation, substance misuse)

An important recent report, Personality disorder: No longer a diagnosis of exclusion, sets out guidance for treating such patients within existing mental health services.

Psychotherapy aiming towards greater insight and improved behaviour patterns benefits some cases. Many patients cannot tolerate in-depth individual work.

Group psychotherapy offers an alternative, where patients can learn from each other. This is the main stay of therapeutic community treatment, where the residents are responsible for setting and maintaining the rules (ìboundariesî, e.g. patients must do no self harm- distress must instead be dealt with by talking to others).

Dialectical behaviour therapy is a fairly new type of treatment for borderline personality disorder. It combines elements of CBT, with ìdialectical thinkingî and ìmindfulnessî.

Nidotherapy is another novel word, at least, and is based on the idea of changing the patientís environment (Latin nidus, nest) in an effort to produce therapeutic progress.

Drug treatment is sometimes helpful, in which case it usually needs to be continued on a long-term basis. Antidepressants, low-dose antipsychotics (sometimes given in depot form), and mood stabilisers (lithium or carbamazepine) have been successfully used in some cases. Drugs with a high potential for dependence, such as benzodiazepines, are best avoided in these patients.

PROGNOSIS Long-term follow-up studies indicate a wide range of outcomes. Some patients improve considerably over time, whereas in other cases the features of disorder become even more deeply ingrained, and the risk of suicide is raised.

SOCIOPATHIC (DYSSOCIAL) PERSONALITY DISORDER The Mental Health Act 1983 (using the older term psychopathic disorder) gives this definition: ìA persistent disorder or disability of mind (whether or not including significant impairment of intelligence) which results in abnormally aggressive or seriously irresponsible conduct on the part of the person concerned.î

Causes

• Genetic predisposition is suggested by adoption studies.
• Brain damage, usually dating from early life, is present in some cases and the EEG may show an immature pattern. Temporal lobe lesions may be especially implicated.
• A disturbed upbringing is often described, suggesting the condition may partly result from lack of guidance in childhood regarding acceptable behaviour.
  

Clinical Features Sociopaths, most of whom are male, consistently behave in ways that are unacceptable to their culture and damaging to themselves, but seem unable to learn from experience. They seek immediate pleasures without considering the long-term consequences, and are unable to make lasting relationships with others, though some possess great superficial charm and are skilled in casual contacts.

Subjects often report frequent changes of job, frequent moves of residence, and multiple sexual partners, and are living under stress of their own making. They often become depressed at such times, and/or experience transient delusions or hallucinations. Drug or alcohol misuse and criminal behaviour are frequent. ìInadequateî, ìaggressiveî and ìcreativeî types have been described. Many prison inmates have sociopathic traits.

Differential Diagnosis

• Psychiatric illness, especially hypomania and schizophrenia.
• Organic brain disease, especially frontal and temporal lobe lesions.
• Drug-induced states, especially amphetamines or LSD.
  

Treatment There is no firm evidence that psychiatric treatment is helpful, but the Mental Health Act 1983 permits compulsory admission if it is considered likely that treatment will ìalleviate or prevent deterioration of the conditionî, and many psychopaths are admitted to regional secure units under the Act.

The most effective management is thought to be psychotherapy in a group composed of other sociopaths. The key point is to encourage the patient to take responsibility for his own conduct. Therapeutic communities for this purpose include those at the Henderson Hospital, Broadmoor Hospital and Grendon Underwood Prison. Individual psychotherapy is seldom successful as patients are often manipulative, and unreliable in attendance.

Lithium and/or long-acting depot antipsychotics are sometimes tried, to attempt to control aggression and mood swings. However, use of medication must be very cautious. As well as elevated risk of overdose, dependence or abuse, it may affect the patientís understanding of his condition.. If the doctor is prescribing, the patient may see himself as mentally ill, and think that he does not have responsibility for his conduct. He might seek to blame the doctor for inadequate treatment if he committed a criminal offence, for example. In general, the role of medication is limited.

Prognosis Flagrant antisocial behaviour usually diminishes with age, but problems with relationships continue. About 5% commit suicide.

REFERENCES
1 Yamagata S et al, J Pers Soc Psychol. 2006 Jun;90(6):987-98. Is the genetic structure of human personality universal? A cross-cultural twin study from North America, Europe, and Asia.
2 WHO 1973 Report Of The International Pilot Study Of Schizophrenia, WHO, Geneva.