Personality Disorders can be considered as extreme expressions of characteristics which we all possess. In the DSM-IV-TR these disorders are subdivided into three groups: (A) the so-called odd/eccentric group, where subjects indeed appear as strange and rather off-beat; (B) the dramatic, emotional or erratic group, in which those affected tend to be histrionic, impulsive and emotionally unstable; and (C) the anxious/fearful group, which comprises people that often express deep-rooted fears and anxiety. The first group includes the Paranoid Personality Disorder, Schizoid Personality Disorder and the Schizotypal Personality Disorder; the second includes the Borderline Personality Disorder, Histrionic Personality Disorder, the Narcissistic Personality Disorder and Antisocial Personality Disorder; and the third group is formed by the Avoidant Personality Disorder, Dependent Personality Disorder and the Obsessive-Compulsive Personality Disorder.

Group A: odd or eccentric disorders
Paranoid Personality Disorder. Subjects presenting a paranoid personality are characterised by deep-rooted suspiciousness, mistrust and diffidence with respect to others. The actions and motivations of others will be analysed carefully in an attempt to discover their hidden threat, betrayal or manipulation, which are often erroneously identified in normally insignificant gestures and/or words. The expectation is always that of being mistreated or exploited, therefore these subjects prefer to remain encapsulated within themselves and are unable to confide in others and establish healthy interpersonal relationships. Their relations with other people are always characterised by doubt and suspicion and quite often also by unjustified jealousy in the case of a sexual partner or spouse. Individual with a paranoid personality describe their relations in detached terms and are unable to let themselves go in the affective sense as they believe that this would result in their becoming vulnerable in the face of possible threats or attacks.

The general attitude of these individuals is one of hostility and they express considerable rancour with respect to people they believe are guilty of plots, betrayals and other actions perpetrated to their detriment. There is a distinct incapacity to forgive presumed offensive action. An example is that of the person who spends his days spying on his neighbours from behind closed shutters in an attempt to quickly uncover the plots he is certain are being laid to harm him or her despite the fact no real proof exists to support such a conviction. Such persons might reach the point where they make telephone calls in which they declare they have discovered everything, and thus the may actively disturb their unwitting ‘victims’. PPD occurs most frequently in males and often presents comorbidity with the Schizotypal Personality Disorder, Borderline Personality Disorder and the Avoidant Personality Disorder (Bernstein, 1994; Morey, 1988).

Schizoid Personality Disorder. This personality type has no desire to nurture social relations and derives no pleasure from them. Those individuals diagnosed as suffering from this condition usually have no intimate friends. They appear insensitive, calm and aloof and manifest no affection or warmth with other people. They rarely refer having strong emotions, they are not interested in sex and find very few activities pleasant. Indifferent towards praise, criticism and other people’s sentiments, such subjects are very solitary figures and dedicate themselves only to interests they can cultivate alone. The disorder often shows comorbidity (see glossary) with the  Schizotypal, Avoidant and Paranoid Personality Disorders as there are many similarities amongst the four conditions. The symptoms of Schizoid Personality Disorder also have many elements in common with the initial phases of Schizophrenia.

Schizotypal Personality Disorder. The modern concept of a schizotypal personality emerged following the studies conducted in Denmark on the adopted children of schizophrenic biological parents (Kety et al., 1968). Although during adulthood some of these children developed an ascertained form of schizophrenia, an even greater number developed what appeared to be a mild form of the disorder. Subjects affected by Schizotypal Personality Disorder generally present the same difficulties in their interpersonal relations as those who suffer from Schizoid Disorder and also excessive social anxiety which their familiarity with others does not manage to dissipate. The disorder also presents various other rather more bizarre symptoms, although these are not so serious to justify a diagnosis of schizophrenia. These latter symptoms are essentially akin to the type that appear in the initial phases of schizophrenia, i.e., strange beliefs, magical thinking, superstitions, being convinced that one has acquired the powers of a clairvoyant and has become telepathic, and also recurring perceptive alterations. For example, these subjects may ‘feel’ close to them the presence of a force or a person who is in fact not there. The speech of persons affected by the disorder is sometimes unusual and not very clear, and their behaviour and appearance may be quite extravagant. Again, by way of an example, they may talk to themselves or wear old, shabby and dirty clothes. Delusions of reference are also often present, whereby they are convinced that certain events or stimuli – entirely unrelated to their own existence - have a particular and unusual meaning, and regard them in particular.

Group B: dramatic, emotional or erratic disorders
Histrionic Personality Disorder. In the past this disorder was known as ‘Hysteria’. It is diagnosed in persons who show behaviour excessively dramatic and ‘histrionic’, and who continuously try to attract the attention of others; for this purpose they also often use their own physical appearance, through eccentric clothing, a particular type of makeup or an unusual colour of the hair. Although they present strong emotions in a theatrical manner, it is believed that their emotions are in fact rather superficial. These are individuals who focus mainly on themselves and are excessively interested in their physical appearance and they feel ill at ease when they are not the centre of attention. These subjects can be sexually provocative and seductive in situations and in ways which are not appropriate and they are easily influenced. Their style of speech is often impressionistic and lacking in detail. For example, they may vehemently express an opinion and yet be unable to support it with appropriate arguments. Histrionic Personality Disorder is more common amongst women than men (Corbitt and Widiger, 1995). The most common comorbidity is with the Borderline Personality Disorder.

Narcissistic Personality Disorder. Subjects showing clear evidence of this disturbance have grandiose ideas about themselves and their capacities. They are convinced they are exceptional people and fantasize continuously about their future success. They are totally concentrated on themselves and seek the constant attention and admiration of others, believing that they can only be understood by very special people or individuals of very high social rank and standing. Their interpersonal relations are disturbed by a lack of empathy (see glossary), sentiments of envy, arrogance, attempts to exploit others and by the conviction they have special rights, as if other people were obliged to render them particular favours and have no right to receive a favour in return. Symptoms of this disorder are frequently concomitant with certain traits of the Borderline Personality Disorder.

Borderline Personality Disorder. Individuals affected by Borderline Personality Disorder present a persistent instability in their interpersonal relations, mood and self image. Their emotions may undergo brusque and sudden changes (although their most common mood is that of anger), as may their consideration of other people. Their relations tend to be very intense, and periods of idealization (see glossary) and overestimation of friends or significant others may rapidly end as the subject quickly veers in the opposite direction, even quickly assuming an attitude of scorn and disdain with respect to the same people. Their relationships are characterised also by exclusiveness and their short duration. Borderline patients can be polemical, irritable, sarcastic and touchy, and very difficult to manage for those who live with them. They present frequent threatening attitudes and also attempts to commit suicide or some form of self-harm, which are induced by a sense of emptiness and depression that chronically afflicts these individuals. Other traits may include gambling, spending sprees, sexual promiscuity and binge eating.