Shorter Oxford Textbook of Psychiatry, 6th Ed.

CHAPTER 12. Paranoid symptoms and syndromes


Paranoid symptoms

Paranoid personality disorder

Paranoid symptoms in psychiatric disorders

Delusional disorders (paranoid psychoses)

Specific delusional disorders

Assessment of paranoid symptoms

Treatment of paranoid symptoms and delusional disorder

Prognosis of delusional disorder


The term paranoid can be applied to symptoms, syndromes, or personality types. Paranoid symptoms are overvalued ideas or delusions which are most commonly persecutory, but not always so (see Box 1.2, p. 11). Paranoid syndromes are those in which paranoid delusions form a prominent part of a characteristic constellation of symptoms, such as pathological jealousy or erotomania. In paranoid personality disorder, there is excessive self-reference and undue sensitiveness to real or imaginary humiliations and rebuffs, often combined with self-importance and combativeness. Thus the term paranoid is descriptive; if we recognize a symptom or syndrome as paranoid, this does not constitute making a diagnosis, but it is a preliminary to doing so. In this respect it is like recognizing stupor or depersonalization.

Paranoid syndromes present considerable problems of classification and diagnosis. The difficulties can be reduced by dividing them into two distinct groups:

• paranoid symptoms occurring as part of another psychiatric disorder, such as schizophrenia, mood disorder, or an organic mental disorder

• paranoid symptoms occurring without evidence for any underlying disorder. This group of disorders has gone by a variety of names, commonly paranoid states or paranoid psychosis, but the ICD-10 and DSM-IV category is delusional disorder. It is this second group that has caused persistent difficulties in several respects—for example, regarding their terminology, their relationship to schizophrenia, and their forensic implications.

This chapter begins with definitions of the common paranoid symptoms, expanding upon their descriptions in Chapter 1, and then reviews the causes of such symptoms. Next there is a short account of paranoid personality. This is followed by a discussion of primary psychiatric disorders with which paranoid symptoms are frequently associated, and the differentiation of these disorders from delusional disorders. The general features of delusional disorder and its major subtypes are then reviewed. A historical perspective is also given, with particular reference to paranoia and paraphrenia. The chapter ends with a summary of the assessment and treatment of patients with paranoid symptoms.

Paranoid symptoms

It was pointed out above that the commonest paranoid delusions are persecutory. The term paranoid is also applied to the less common delusions of grandeur and jealousy, and sometimes to delusions concerning love, litigation, or religion. It may seem puzzling that such varied delusions should be grouped together. The reason is that the central abnormality implied by the term paranoid is a morbid distortion of beliefs or attitudes concerning relationships between oneself and other people. If someone believes falsely or on inadequate grounds that he is being victimized, or exalted, or deceived, or loved by a famous person, then in each case he is construing the relationship between himself and other people in a morbidly distorted way.

The varieties of paranoid symptom were discussed in Chapter 1, but important ones are also outlined in Box 12.1 for convenience. The definitions are derived from the glossary to the Present State Examination (see p. 65; Wing et al., 1974).

Causes of paranoid symptoms

When paranoid symptoms occur as part of another psychiatric disorder, the main aetiological factors are those that determine the primary illness. However, the question still arises as to why some people develop paranoid symptoms, while others do not. This has usually been answered in terms of premorbid personality and social isolation.

Premorbid personality

Many writers, including Kraepelin, have held that paranoid symptoms are most likely to occur in patients with premorbid personalities of a paranoid type (see next section). Kretschmer (1927) also believed this, and thought that such people developed sensitive delusions of reference (‘sensitive Beziehungswahn’) as an understandable psychological reaction to a precipitating event. Modern studies of so-called late-onset paraphrenia have supported these views (see Box 12.2 below). Thus Kay and Roth (1961) found paranoid or hypersensitive personalities in over half of their group of 99 subjects with late-onset paraphrenia.

Box 12.1 Some paranoid symptoms

Ideas of reference

Ideas of reference are held by people who are unduly self-conscious. The subject cannot help feeling that people take notice of him in buses, restaurants, or other public places, and that they observe things about him that he would prefer not to be seen. He realizes that this feeling originates within himself and that he is no more noticed than other people, but all the same he cannot help the feeling, which is quite out of proportion to any possible cause.

Delusions of reference

Delusions of reference consist of an elaboration of ideas of reference, to the point that the beliefs become delusional. The whole neighbourhood may seem to be gossiping about the subject, far beyond the bounds of possibility, or he may see references to himself in the media. He may hear someone on the radio say something connected with a topic he has just been thinking about, or he may seem to be followed, his movements observed, and what he says recorded. The importance of distinguishing a delusion of reference from an idea of reference is that the former is a symptom of psychosis.

Delusions of persecution

When a person has delusions of persecution he believes that a person, organization, or power is trying to kill him, harm him in some way, or damage his reputation. The symptom may take many forms, ranging from the direct belief that he is being hunted down by specific people, to complex, bizarre, and impossible plots.

Delusions of grandeur

These may be divided into delusions of grandiose ability and delusions of grandiose identity. The subject with delusions of grandiose ability thinks that he is chosen by some power, or by destiny, for a special purpose because of his unusual talents. He may think that he is able to read people’s thoughts, is much cleverer than anyone else, or has invented machines or solved mathematical problems beyond most people’s comprehension.

The subject with delusions of grandiose identity believes that he is famous, rich, titled, or related to prominent people. He may believe that he is a changeling and that his real parents are royalty.

Freud proposed that, in predisposed individuals, paranoid symptoms could arise through a convoluted process involving the defence mechanisms of denial and projection, based upon his study of Daniel Schreber, the presiding judge of the Dresden Appeal Court (Freud, 1911). Freud never met Schreber, but read the latter’s autobiographical account of his paranoid illness (now generally accepted as being paranoid schizophrenia), together with a report by Weber, the physician in charge. Freud speculated that Schreber could not consciously admit his homosexuality, and projected his unacceptable desires (‘I do not love him, he loves me’) and then inverted this with another denial (‘he does not love me, he hates me’). This configuration was abandoned fairly early on, and never had much clinical support.

Social isolation and deafness

Social isolation may also predispose to the emergence of paranoid symptoms. Prisoners (especially those in solitary confinement), refugees, and migrants have all been considered to be prone to paranoid symptoms and syndromes, with social isolation being the common factor. However, there are no data that unambiguously support this view, and there are some which suggest other explanations. For example, the association between migration and psychosis is better explained in terms of broader psychosocial factors or marginalization, rather than just isolation (Singh and Burns, 2006; see also Chapter 11).

There is better evidence that the social isolation produced by deafness increases the risk of paranoid symptoms, as originally noted by Kraepelin. Houston and Royse (1954) found an association between deafness and paranoid schizophrenia, while Kay and Roth (1961) found hearing impairment in 40% of patients with late-onset paraphrenia. Subsequent studies have confirmed that hearing impairment is a risk factor for disorders in which paranoid symptoms occur, and that this relationship is stronger in but not limited to the elderly (David et al., 1995). However, it should be remembered that the great majority of deaf people do not become paranoid, and many deaf people may not be socially isolated.

Paranoid personality disorder

The concept of personality disorder was discussed in Chapter 7, and paranoid personality disorder was briefly described there. It is characterized by the following:

• extreme sensitivity to setbacks and rebuffs

• suspiciousness

• a tendency to misconstrue the actions of others as hostile or contemptuous

• a combative and inappropriate sense of personal rights.

This definition embraces a wide range of types. At one extreme is the excessively sensitive young person who shrinks from social encounters and thinks that everyone disapproves of him. At the other is the assertive and challenging woman who flares up at the least provocation. A recent American study found a 4.4% prevalence of DSM-IV paranoid personality disorder, which is higher than previous estimates; the study also showed that the disorder had a significant impact on social and role functioning (Grant et al., 2004).

Because of the implications for treatment, it is important to distinguish paranoid personality disorder from the paranoid syndromes (delusional disorders) to be described later. The distinction can be very difficult to make, and is based on the fact that in paranoid personality disorder there are no delusions (only overvalued ideas), and no hallucinations. Considerable skill is needed to separate paranoid ideas from delusions. The criteria for doing so were given in Chapter 1, and exemplified by the comparison made above between ideas of reference and delusions of reference. In reality, the conditions probably lie along a continuum. Thus family studies indicate a genetic relationship between paranoid personality disorder and delusional disorder (see below), whereas individuals with paranoid personality traits are at increased risk of developing a delusional disorder.

For a review of paranoid personality disorder, see Carroll (2009).

Paranoid symptoms in psychiatric disorders

Paranoid symptoms are often secondary to a primary psychiatric disorder. Thus when paranoid symptoms, especially persecutory delusions, are elicited it is important to assess for the other features of these disorders. The diagnosis of delusional disorder, to be considered below, is in many respects a ‘residual’ category, used for patients whose delusions cannot be attributed to one of these other conditions. As the primary disorders are described at length in other chapters, they will be mentioned only briefly here.

Paranoid symptoms in organic disorders

It is important to consider an organic aetiology for paranoid symptoms, especially in the elderly or in cases where there is other evidence for a medical illness. For a review of organic causes of paranoid symptoms and delusional disorders, see Gorman and Cummings (1990).

Paranoid symptoms are common in delirium. Impaired grasp of what is going on around the patient may give rise to apprehension and misinterpretation, and so to suspicion. Delusions may then emerge which are usually transient and disorganized; these may lead to disturbed behaviour, such as querulousness or aggression. Similarly, persecutory delusions commonly occur at some stage in dementia, and are occasionally the presenting feature. Finally, paranoid symptoms and delusional disorders may occur with focal brain lesions of various causes, including tumour, stroke, and trauma. Some examples are given later in this chapter when the specific delusional disorders are considered.

Paranoid symptoms in substance misuse disorders

Paranoid symptoms occur in many substance misuse disorders, especially those associated with amphetamines, cocaine, and alcohol. An important example is the association between alcohol misuse and morbid jealousy, described below. Some therapeutic drugs can also precipitate paranoid symptoms, such as L-DOPA (Gorman and Cummings, 1990).

Paranoid symptoms in mood disorders

Paranoid symptoms are not uncommon in patients with severe depressive disorders, and paranoid delusions are a feature of psychotic depression. Conversely, depressive symptoms often occur in delusional disorders, although the diagnostic criteria for the latter require that their total duration is relatively brief (see below). In practice, it is sometimes difficult to determine whether the paranoid symptoms are secondary to depressive disorder, or vice versa, as both scenarios are common. The distinction is of some importance, as the two disorders differ with regard to treatment and prognosis. A depressive disorder is likely if the mood changes have occurred earlier and are of greater intensity than the paranoid features. Previous psychiatric history and family history may also be useful pointers. Finally, in depressive disorder the patient typically accepts the persecution as justified by their own guilt or wickedness. This is a useful point clinically, as it contrasts with non-affective psychoses, in which such persecutions are bitterly resented.

Paranoid symptoms also occur in mania, and are typically mood-congruent and thus grandiose rather than persecutory.

Paranoid symptoms and paranoid schizophrenia

Paranoid schizophrenia was described in Chapter 11. Its distinction from delusional disorders has been particularly problematic, both conceptually and practically (see Box 12.2), but the difficulties can be decreased by noting the differences in their core features (compare Table 12.1 with Box 12.2). Three features aid the distinction in cases of doubt.

Box 12.2 Historical background: paranoia and paraphrenia

The terms paranoia and paraphrenia have played a prominent part in psychiatric thought. Much can be learned from reviewing the conceptual difficulties associated with them.

The term paranoia, from which the modern adjective paranoid is derived, has a long and chequered history. It has probably given rise to more controversy and confusion of thought than any other term used in psychiatry. A comprehensive review of the large body of literature, which is mostly German, and from the period before the 1970s has been provided by Lewis (1970) (see also Box 1.2). The word is derived from the Greek para (beside) and nous (mind). It was used in ancient Greek literature to mean ‘out of mind’ (i.e. of unsound mind or insane). This broad usage was revived in the eighteenth century, but when it came into prominence in the second half of the nineteenth century, in German psychiatry, it became particularly associated with conditions characterized by delusions of persecution and grandeur. The German term Verrucktheit was often applied to these conditions, but was eventually superseded by paranoia. There were many different conceptions of these disorders. The main issues, most of which remain today, can be summarized as follows.

• Did these conditions constitute a primary disorder, or were they secondary to another disorder?

▸• Did they persist unchanged for many years, or were they a stage in an illness which later manifested deterioration of intellect and personality?

• Did they sometimes occur in the absence of hallucinations, or were hallucinations an invariable accompaniment?

• Were there forms with a good prognosis?

Kahlbaum raised these issues as early as 1863, when he classified paranoia as an independent primary condition which would remain unchanged over the years. Kraepelin had a strong influence on the conceptual history of paranoia, although he was never comfortable with the term, and his views changed strikingly over the years. In 1896 he used the term only for incurable, chronic, and systematized delusions without severe personality disorder. In the sixth edition of his textbook he wrote:

The delusions in dementia praecox [schizophrenia] are extremely fantastic, changing beyond all reason, with an absence of system and a failure to harmonize them with events of their past life; while in paranoia the delusions are largely confined to morbid interpretations of real events, are woven together into a coherent whole, gradually becoming extended to include even events of recent date, and contradictions and objects are apprehended and explained. (Kraepelin, 1904, p. 199)

In later descriptions, Kraepelin (1919) used the distinction made by Jaspers (1913) between personality development and disease process. He proposed paranoia as an example of the former, in contrast to the disease process of dementia praecox. In his final account, Kraepelin (1919) developed these ideas by distinguishing between dementia praecox, paranoia, and a third paranoid psychosis, namely paraphrenia. He made the following suggestions:

• Dementia praecox had an early onset and a poor outcome, ending in mental deterioration, and was fundamentally a disturbance of affect and volition.

• Paranoia was restricted to patients with late onset of completely systematized delusions and a prolonged course, usually without recovery, but not inevitably deteriorating. An important point was that the patient did not have hallucinations.

• Paraphrenia was somewhat intermediary, in that the patient had unremitting systematized delusions but did not progress to dementia. The main difference from paranoia was that the patient with paraphrenia had hallucinations.

Bleuler’s concept of the paranoid form of dementia praecox (which he later called paranoid schizophrenia) was broader than that of Kraepelin (Bleuler, 1906, 1911). Thus Bleuler did not regard paraphrenia as a separate condition, but as part of dementia praecox. However, he accepted Kraepelin’s view of paranoia as a separate entity, although he differed from Kraepelin in maintaining that hallucinations could occur in many cases. Bleuler was particularly interested in the psychological development of paranoia; at the same time he left open the question of whether paranoia had a somatic pathology.

From this time, two views of paranoia predominated. The first was that paranoia was distinct from schizophrenia and psychogenic in origin. The second view was that paranoia was part of schizophrenia. Some celebrated studies of individual cases appeared to support the first theme. For example, Gaupp (1974) made an intensive study of the diaries and mental state of the mass murderer Ernst Wagner, who murdered his wife, four children, and eight other people as part of a careful plan to revenge himself on his supposed enemies. Gaupp concluded that Wagner suffered from paranoia in the sense described by Kraepelin. At the same time, he believed that Wagner’s first recognizable delusions developed as a psychogenic reaction. The most detailed argument for psychogenesis was put forward by Kretschmer (1927) in his monograph Der Sensitive Beziehungswahn. Kretschmer believed that paranoia should not be regarded as a disease, but as a psychogenic reaction occurring in people with particularly sensitive personalities. However, many of Kretschmer’s cases would nowadays be classified as schizophrenia. In 1931, Kolle put forward evidence for the second view, that paranoia is part of schizophrenia. He analysed a series of 66 patients with so-called paranoia, including those diagnosed by Kraepelin in his Munich clinic. For several reasons, both symptomatic and genetic, Kolle came to the conclusion that paranoia was really a mild form of schizophrenia.

Considerably less has been written about paraphrenia. However, it is interesting that Mayer (1921), following up Kraepelin’s series of 78 paraphrenic patients, found that 50 of them had developed schizophrenia. He found no difference in original clinical presentation between those who developed schizophrenia and those who did not. Since then paraphrenia has increasingly been regarded as late-onset schizophrenia or schizophrenia-like disorder of good prognosis. Kay and Roth (1961) used the term late paraphrenia to denote paranoid conditions in the elderly that were not due to primary organic or affective illnesses. These authors found that a large majority of their 99 patients had the characteristic features of schizophrenia.

In current classifications, the term paranoia has, in effect, been replaced by delusional disorder. Paraphrenia does not feature either, but it continues to be used clinically to describe chronic, atypical, paranoid psychoses of middle and late life.

Table 12.1 DSM-IV criteria for delusional disorder

A. Non-bizarre delusions (i.e. involving situations that occur in real life, such as being followed, poisoned, infected, loved at a distance, or deceived by a partner or lover, or having a disease) of at least 1 month’s duration

B. Criterion A for schizophrenia has never been met. Note: Tactile and olfactory hallucinations may be present in delusional disorder if they are related to the delusional theme

C. Apart from the impact of the delusion(s) or its ramifications, functioning is not markedly impaired and behaviour is not obviously odd or bizarre

D. If mood episodes have occurred concurrently with delusions, their total duration has been brief relative to the duration of the delusional periods

E. The disturbance is not due to the direct physiological effects of a substance (e.g. a drug of abuse, a medication) or a general medical condition

• The diagnosis of paranoid schizophrenia rather than delusional disorder is suggested if the paranoid delusions are particularly odd in content (often referred to by psychiatrists as bizarre delusions). Except in extreme cases, judgement as to how bizarre they are must be arbitrary (see Chapter 2; Cermolacce et al., 2010). DSM-IV defines non-bizarre delusions as involving situations that could conceivably occur in real life (e.g. being followed, poisoned, or loved at a distance). ICD-10, perhaps recognizing the difficulty of defining ‘bizarre’, omits this criterion

• In schizophrenia, delusions tend to be fragmented and multiple, whereas in delusional disorder they are systematized and based around a single, internally consistent theme. In delusional disorder, the delusional system is also characteristically encapsulated, such that the rest of the mental state can appear remarkably normal, in contrast to schizophrenia.

• Patients with paranoid schizophrenia often have auditory hallucinations, and the content of these appears to be unrelated to their delusions. In delusional disorder, hallucinations are very rare, and when they do occur they are fleeting and clearly related to the delusions.

Paranoid symptoms in schizophrenia-like syndromes

Paranoid symptoms are features of several schizophrenia-like syndromes which were discussed in Chapter 11 (and are listed in Table 12.1). These include the DSM-IV categories of brief psychotic disorders and schizophreniform disorder, and the ICD-10 categories grouped under the heading ‘Acute and transient psychotic disorders.’

Delusional disorders (paranoid psychoses)

As mentioned in the introduction, the terminology and classification of psychoses which are neither affective, organic, nor schizophrenia have been disputed for many years. Box 12.2 summarizes the main historical terms and themes, and provides the backdrop to the way in which the disorders are currently categorized. In this section, the core features of delusional disorders—the current terminology for these conditions—are described. The specific types of delusional disorder are covered in the following section.

Classification of delusional disorder

DSM-IV uses the term delusional disorder to describe a disorder with persistent, non-bizarre delusions that is not due to any other disorder. It is synonymous with the widely used term paranoid psychosis, and includes the non-specific term paranoid states. ICD-10 has a similar category of persistent delusional disorders. The essence of the modern concept of delusional disorder is that of a stable delusional system that develops insidiously in a person in middle or late life. The delusional system is encapsulated, and there is no impairment of other mental functions. The patient can often continue working, and his social life may be maintained fairly well.

The criteria for delusional disorder in DSM-IV are summarized in Table 12.1, with the subsequent description of five specific subtypes of delusional disorder and two other categories:

• persecutory

• jealous

• erotomanic

• somatic

• grandiose

• mixed

• unspecified.

ICD-10 gives a similar definition for the principal category (F22.0) of persistent delusional disorders. Unlike DSM-IV, the symptoms must have been present for at least 3 months, and the delusions are not required to be ‘non-bizarre.’ ICD-10 also includes litigious and self-referential subtypes, and has a separate subcategory (F22.8) of ‘other persistent delusional disorders’ (see below).

For reviews of delusional disorder, see Sedler (1995) and Munro (2009).

Epidemiology of delusional disorder

Delusional disorder is regarded as being an uncommon illness, although there are relatively few data. Kendler (1982) reviewed the literature and reported an incidence of 1–3 per 100 000 per year, with delusional disorder constituting 1–4% of all psychiatric admissions. In a community survey of over 5000 people aged 65 years or over, Copeland et al. (1998) found a prevalence of 0.04% for delusional disorder. In a retrospective study of over 10 000 outpatients, Hsiao et al. (1999) diagnosed 86 individuals (0.83%) as meeting DSM-IV criteria for delusional disorder of various kinds (see Table 12.2). The disorder was slightly more common in women than in men, and the mean age of onset of symptoms was 42 years. Finally, in a large population survey, delusional disorder had a lifetime prevalence of 0.18% (Peraala et al., 2007).

Significant depressive symptoms are common in delusional disorder (note category D in Table 12.1), being present in about one-third of subjects (Hsaio et al., 1999; Serretti et al., 2004).

Aetiology of delusional disorder

What little is known about the aetiology of delusional disorder is based upon its relationship to, and comparison with, schizophrenia, paranoid personality disorder, and depressive disorder (Kendler, 1982). This question has been addressed by family and neurobiological studies. However, the relatively small sample sizes and varying diagnostic definitions mean that few conclusions can be drawn. Psychological explanations for delusional disorder centre upon the delusions themselves, see Box 1.1, p. 9, and Freeman (2007).

Table 12.2 Subtypes of delusional disorder in 86 Chinese outpatients


Family studies of delusional disorder

First-degree relatives of patients with delusional disorder have an increased incidence of paranoid personality disorder (Kendler et al., 1985). The familial relationship of delusional disorder to schizophrenia is less clear. Although the risk of delusional disorder is increased in first-degree relatives of patients with schizophrenia, relatives of patients with delusional disorder do not have an increased risk of schizophrenia or schizotypal personality (Kendler et al., 1995; Kendler and Walsh, 1995; Tienari et al., 2003). This familial association pattern has been called asymmetric co-aggregation, and may be due to a number of factors:

• differences in the incidence rates of the two disorders in the general population

• differences in the diagnostic error rate between probands and relatives (probands are usually subject to more intensive assessment)

• a higher genetic loading for severe illness in those who come to medical attention (and are therefore assessed as probands).

Overall, there appears to be a weak genetic link between delusional disorder and, on the one hand, schizophrenia, and on the other, paranoid personality disorder. However, the extent of this overlap is unclear. Most authorities would include delusional disorder as part of the schizophrenia spectrum (Kendler, 2003).

There is a familial association between alcoholism and delusional disorder (Kendler and Walsh, 1995), which could explain the association between morbid jealousy and alcohol misuse (see below).

No individual loci or genes contributing to delusional disorders have been identified.

Neurobiological studies

Structural MRI studies suggest that elderly patients with delusional disorder have enlarged cerebral ventricles, similar to patients with schizophrenia (Howard et al., 1995). However, this finding could also reflect the frequency of an underlying neurodegenerative disorder in this population.

Specific delusional disorders

As noted above, specific subtypes of delusional disorder are recognized, on the basis of the content of the predominant delusion(s) (see Table 12.3). Historically, these symptoms have been of particular interest to French psychiatrists. Classification in this area is confusing for two reasons.

• Some of the disorders are often referred to by older, eponymous terms, or by categories that are not included in DSM-IV or ICD-10 but which remain in common usage.

• Some of the syndromes can be viewed as symptoms (e.g. delusional misidentification), or can occur secondary to other psychiatric disorders.

In this section we also consider stalking and persistent litigants, as both behaviours may be secondary to delusional disorder.

Pathological jealousy

Pathological or morbid jealousy (other synonyms are listed in Table 12.3) will be described first and in most detail as it is the archetypal delusional disorder; it is also the commonest (other than ‘persecutory delusional disorder’, not otherwise specified) and, importantly, appears to carry the greatest risk of dangerousness.

The essential feature is an abnormal belief that the patient’s partner is being unfaithful. The condition is termed pathological because the belief, which may be a delusion or an overvalued idea, is held on inadequate grounds and is unaffected by rational argument. The belief is often accompanied by strong emotions and characteristic behaviour, but these do not in themselves constitute pathological jealousy. A man who finds his wife in bed with a lover may experience extreme jealousy and may behave in an uncontrolled way, but this should not be called pathological jealousy. The term should be used only when the jealousy is based on unsound evidence and reasoning.

Table 12.3 Types of delusional disorder


The main sources of information about pathological jealousy come from the classic paper by Shepherd (1961), and from surveys by Langfeldt (1961), Vaukhonen (1968), and Mullen and Maack (1985). Shepherd examined the hospital case notes of 81 patients in London, and Langfeldt did the same for 66 patients in Norway. Vaukhonen conducted an interview study of 55 patients in Finland, and Mullen and Maack examined the hospital case notes of 138 patients.

Pathological jealousy appears to be more common in men than in women, with the surveys mentioned above finding that about two men were affected for every woman. The frequency of the condition in the general population is unknown, but it is not uncommon in psychiatric practice. Each case merits careful attention, not only because of the great distress that the condition causes within relationships, but also because these individuals may be highly dangerous.

Clinical features of pathological jealousy

As indicated above, the main feature is an abnormal belief in the partner’s infidelity. This may be accompanied by other abnormal beliefs—for example, that the partner is plotting against the patient, trying to poison him, taking away his sexual capacities, or infecting him with venereal disease. The mood of the pathologically jealous patient may vary with the underlying disorder, but often it is a mixture of misery, apprehension, irritability, and anger.

Typically, the behaviour involves an intensive search for evidence of the partner’s infidelity—for example, by looking through their diaries and by examining bed linen and underwear. The patient may follow the partner about, or engage a private detective. The jealous person often cross-questions the partner incessantly. This may lead to violent quarrelling and paroxysms of rage in the patient. Sometimes the partner becomes exasperated and worn out, and is finally goaded into making a false confession. If this happens, the jealousy is inflamed rather than assuaged. An interesting feature is that the jealous person often has no idea who the supposed lover may be, or what kind of person they may be. Moreover, he may avoid taking steps that could produce unequivocal proof one way or the other.

Behaviour may be strikingly abnormal. A successful city businessman carried a briefcase that contained not only his financial documents but also a machete for use against any lover who might be detected. A carpenter installed an elaborate system of mirrors in his house so that he could watch his wife from another room. A third patient avoided waiting alongside another car at traffic lights, in case his wife, who was sitting in the passenger seat, might surreptitiously make an assignation with the other driver.

Aetiology of pathological jealousy

Pathological jealousy, like other paranoid symptoms and syndromes, is associated with a range of primary disorders (see Table 12.4). In the surveys mentioned, the frequencies of disorders varied, probably reflecting the population studied and the diagnostic scheme used. For example, paranoid schizophrenia was reported in 17–44% of patients, depressive disorder in 3–16%, neurosis and personality disorder in 38–57%, alcoholism in 5–7%, and organic disorders in 6–20%.

The role of personality in the genesis of pathological jealousy should be emphasized. It is often found that the patient has a pervasive sense of inadequacy, together with low self-esteem. There is a discrepancy between his ambitions and his attainments. Such a personality is particularly vulnerable to anything that may threaten this sense of inadequacy, such as loss of status or advancing age. In the face of such threats the person may project the blame on to others, and this may take the form of jealous accusations of infidelity. As mentioned earlier, Freud believed that unconscious homosexual urges played a part in all jealousy, but clinical studies do not support an association between homosexuality and pathological jealousy. Similarly, although pathological jealousy has sometimes been attributed to the onset of sexual difficulties, there is no good evidence of such an association.

Prognosis of pathological jealousy

Little is known about the prognosis of pathological jealousy. It probably depends on a number of factors, including the nature of any underlying psychiatric disorder and the patient’s premorbid personality. When Langfeldt (1961) followed up 27 of his patients after 17 years, he found that over 50% of them still had persistent or recurrent jealousy. This confirms a general clinical impression that the prognosis is often poor.

Table 12.4 Disorders associated with pathological jealousy


Mood disorder

Organic disorder

Substance misuse (especially alcohol)

Paranoid personality disorder

Risk of violence

Although there are no reliable estimates of the risks of violence, there is no doubt that people with pathological jealousy can be dangerous (Silva et al., 1998). Three out of 81 patients in Shepherd’s series had shown homicidal tendencies (Shepherd, 1961). In addition to homicide, the risk of physical injury inflicted by jealous patients is considerable. In Mullen and Maack’s series, around 25% had threatened to kill or injure their partner, and 56% of men and 43% of women had been violent towards or threatened the supposed rival (Mullen and Maack, 1985). Recently, Schanda et al. (2004), studying convicted murderers in Austria, confirmed that delusional disorder (subtype not specified) is associated with homicide, with an odds ratio of 6. There is also a risk of suicide, particularly when an accused partner finally decides to end the relationship.

Assessment of pathological jealousy

The assessment of a patient with pathological jealousy should be particularly thorough, and should always include the partner, who should be interviewed separately whenever possible.

The partner may give a much more detailed account of the patient’s morbid beliefs and actions than can be elicited from the patient. The doctor should try to find out tactfully how firmly the patient believes in the partner’s infidelity, how much resentment he feels, and whether he has contemplated any vengeful action. What factors provoke outbursts of accusations and questioning? How does the partner respond to such outbursts? How does the patient respond in turn to the partner’s behaviour? Has there been any violence so far? Has there been any serious injury?

In addition to these enquiries, the doctor should take a detailed relationship and sexual history from both partners, and assess for underlying psychiatric disorder, as this will have implications for treatment.

Treatment of pathological jealousy

The treatment of pathological jealousy, as with other delusional disorders, is in principle fairly straightforward, the mainstay being antipsychotic drugs, but in practice can be very difficult because of the patient’s lack of insight and their reluctance to collaborate with the treatment plan. Furthermore, there is a lack of randomized evidence.

Adequate treatment of any associated disorder such as schizophrenia or a mood disorder is a first requisite. If alcohol or other substance misuse is present, specific treatment will be needed. In other cases the pathological jealousy may be the symptom of a delusional disorder, or an overvalued idea in a patient with low self-esteem and personality difficulties.

If the jealousy appears to be delusional in nature, a careful trial of an antipsychotic drug is worthwhile, although the results are often disappointing. As noted above, even when depressive disorder is not the primary diagnosis, it frequently complicates pathological jealousy and may worsen it. Treatment with an antidepressant may help in these circumstances, and also when the jealousy appears to be an overvalued idea rather than a delusion.

Psychotherapy may be given to patients in cases where the jealousy appears to arise from personality problems. One aim is to reduce tensions by allowing the patient (and their partner) to ventilate their feelings. Behavioural methods include encouraging the partner to produce behaviour that reduces jealousy, for example, by refusal to argue, depending on the individual case. A study of the use of cognitive therapy, in which patients were encouraged to identify faulty assumptions and were taught strategies of emotional control, gave superior results compared with a waiting-list control group (Dolan and Bishay, 1996).

If there is no response to outpatient treatment, or if the risk of violence is high, inpatient care may be necessary. Not uncommonly, however, the patient appears to improve as an inpatient, only to relapse on discharge.

If there appears to be a risk of violence, the doctor should warn the partner, even if this involves a breach of confidentiality (see p. 73). In some cases the safest procedure is to advise separation. It is not uncommon for feelings of pathological jealousy to wane once a relationship has ended. Sometimes, however, the problem re-emerges if the patient enters a new relationship.

Erotomania and erotic delusions

Erotic delusions can occur in any psychotic disorder, especially paranoid schizoophrenia, but they are the predominant and persistent symptom in a form of delusional disorder called erotomania. It was the French psychiatrist, De Clérambault, who in 1921 proposed that a distinction should be made between paranoid delusions and delusions of passion. The latter differed in their pathogenesis and in being accompanied by excitement. This distinction is of historical interest only, but the syndrome is still known as De Clérambault’s syndrome.

Erotomania is rare and occurs almost entirely in women, although Taylor et al. (1983) reported four cases in a series of 112 men charged with violent offences. The woman, who is usually single, believes that an exalted person is in love with her. The supposed lover is usually inaccessible, as he is already married, or is a famous person. According to De Clérambault, the infatuated woman believes that it is the supposed lover who first fell in love with her, and that he is more in love with her than she is with him. She derives satisfaction and pride from this belief. She is convinced that the supposed lover cannot be a happy or complete person without her. The patient often believes that the supposed lover is unable to reveal his love for various unexplained reasons, and that he has difficulties in approaching her, has indirect conversations with her, and has to behave in a paradoxical and contradictory way. The woman may cause considerable nuisance to the supposed lover. She may be extremely tenacious and impervious to reality. Other patients turn from a delusion of love to a delusion of persecution, become abusive, and make public complaints about the supposed lover. This was described by De Clérambault as two phases—hope followed by resentment.

There are few data regarding the treatment and outcome of erotomania (Kelly, 2005). For a review of the concept of erotomania, see Berrios and Kennedy (2002).


A proportion of ‘stalkers’ appear to suffer from delusional disorders, including erotomania, which is why the topic is mentioned here.

There is no clear consensus about the definition of stalking. Most formulations contain the following elements:

• a pattern of intrusive behaviour

• the intrusive behaviour is associated with implicit or explicit threats

• the person being stalked experiences fear and distress.

Stalkers typically follow their victim around and loiter outside their house or place of work. Unwanted communications by telephone, letter, or graffiti, and, in more recent times, by email, are very common. Behaviour can then become more threatening, with hoax advertisements or orders for services, scandalous rumour mongering, damage to the victim’s property, threats of violence, and actual assault.

Stalkers are a heterogeneous group with differing underlying psychopathologies (Dressing et al., 2006). Some, usually women, have erotomania or erotic delusions secondary to other psychotic disorders. More commonly, stalkers suffer from personality disorder, predominantly with borderline, narcissistic, and socio-pathic traits. They have often had a relationship with their victim that may have been quite superficial; in other cases, however, a serious relationship has cooled. A previous history of domestic violence in the relationship puts the victim at particularly high risk of assault and injury. Whether or not the victim suffers actual assault, they invariably experience severe psychological stress, which can lead to anxiety and mood disorders and posttraumatic stress disorder. Risk assessment is important (Mullen et al., 2006). For a review of stalking, see Mullen et al. (2000) (and see also Chapter 24).

Somatic delusional disorder

People with somatic delusional disorder believe that they suffer from a physical illness, deformity, or infestation (e.g. delusional parasitosis, also called Morgellon’s disease). The term encompasses monosymptomatic hypochondriacal psychosis, as there is often a single, intense delusional belief of this kind. Somatic delusional disorder needs to be distinguished from the hypochondriacal delusions (and somatic hallucinations) that can occur in other disorders (e.g. schizophrenia, psychotic depression, cocaine abuse), and from genuine somatic symptoms that occur secondary to organic disorders (e.g. the pruritus of hepatic failure). It must also be distinguished from the common occurrence of obsessional thoughts or overvalued ideas about similar bodily issues. A specific example of the latter is body dysmorphic disorder (also called dysmor-phophobia). In fact there is much overlap clinically, and perhaps therapeutically, between delusional and non-delusional forms of body dysmorphic disorder (Phillips, 2004; Phillips et al., 2006).

Because of the content of the belief, somatic delusional disorders often present to the relevant medical specialism—for example, body dysmorphic disorder to plastic surgeons, or delusional parasitosis to dermatologists (e.g. Lepping et al., 2010). To ensure correct identification and appropriate treatment, it is necessary that the physician recognizes the nature of the disorder, and is able either to treat it or to involve a psychiatrist in its management. However, this does not always occur, and in any event patients are often reluctant to accept the diagnosis.

Querulant delusions and reformist delusions

Querulant delusions were the subject of a special study by Krafft-Ebing (1888). Patients with this kind of delusion indulge in a series of complaints and claims lodged against the authorities. Closely related to querulant patients are paranoid litigants, who undertake a succession of lawsuits, and become involved in numerous court hearings, in which they may become passionately angry and may make threats against the magistrates. The characteristics of persistent litigants have been reviewed by Lester et al. (2004).

Baruk (1959) described ‘reformist delusions’, which are based on religious, philosophical, or political themes. People with these delusions constantly criticize society and sometimes embark on elaborate courses of action. Their behaviour may be violent, particularly when the delusions are political. Some political assassins fall within this group. It is extremely important that this diagnosis is made on clear psychiatric grounds rather than political grounds, as occurred in the former Soviet Union (see Chapter 2).

Delusional misidentification syndrome

Another group of delusions involve different aspects of misidentification, either of the self or of others. Like all delusions, they often occur in other psychotic disorders, especially schizophrenia and organic disorders, but they can also occur in isolation, and have been given the collective label of delusional misidentification syndrome (Ellis and Young, 1990; Christodoulou, 1991). This category is not named in ICD-10 or DSM-IV, but constitutes an example of ‘other persistent delusional disorders’ coded in the former. One argument for bringing them together is that they all appear to be ‘face-processing disorders’, and associated with abnormalities in the posterior part of the right hemisphere, where the systems responsible for face recognition are located (Cutting, 1991). Note also the seemingly close relationship of these disorders to the neurological category of prosopagnosia (the inability to recognize familiar faces). Interestingly, the delusions are specific to a few, usually familiar, people, and recognition of other faces (and objects) is not impaired. Although the beliefs are delusional, the patient is aware that something is wrong with the ‘replacement’ person. The patient may be extremely distressed, and may occasionally act against individuals whom they believe to be impostors.

Four main variants of delusional misidentification are recognized. In each case there is debate as to whether they constitute a symptom or a syndrome.

Capgras syndrome

In this rare condition—which is really a delusion rather than a syndrome, hence its alternative name, Capgras delusion—the patient believes that a person closely related to her (often her partner) has been replaced by a double. She accepts that the misidentified person has a strong resemblance to the familiar person, but still believes that they are different people. Some patients with Capgras syndrome may behave dangerously by attacking the presumed double. This condition is seen more often in women than in men. A history of depersonalization, derealization, or déjà vu is not unusual. Schizophrenia is said to be the most frequent diagnosis (Berson, 1983), although in older subjects, Lewy body disease or other neurodegenerative disorders are common (Josephs, 2007). The syndrome is an example of a reduplicative paramnesia.

The name derives from the classic description by Capgras and Reboul-Lachauz in 1923, who called it l’illusion des sosies (illusion of doubles). However, as noted above, it is a delusion, not an illusion. For a review of Capgras syndrome, see Edelstyn and Oyebode (1999).

Fregoli syndrome

In this condition, also called the Fregoli delusion, the patient believes that one or more individuals have changed their appearance to resemble familiar people, usually in order to persecute the patient in some way. The symptom is usually associated with schizophrenia or with organic brain disease (Portwich and Barocka, 1998). Its name derives from an actor called Fregoli who had remarkable skill in changing his facial appearance. It was originally described by Courbon and Fail in 1927. The condition is even rarer than the Capgras delusion.


In this syndrome, the patient believes that one or more individuals have been transformed, both physically and psychologically, into another person or people, or that people have exchanged identities with each other. As with the other forms of delusional misidentification, note that intermetamorphosis is not a hallucination—the abnormality is one of interpretation, not misperception.

The syndrome of subjective doubles

In the syndrome of subjective doubles, the patient has the delusion that another person has been physically transformed into his own self, like a doppelganger.

Shared (induced) delusional disorder

Sometimes a person who is in a close relationship with someone who already has an established delusional system develops similar ideas. The commonest term is a folie à deux, although the ICD-10 category is shared delusional disorder, and the DSM-IV term is induced delusional disorder. The condition has also been called communicated insanity. The frequency of induced psychosis is not known, but it is low. Sometimes more than two people are involved (folie à plusieurs), but this is exceedingly rare. It has also been speculated that some apocalyptic cults involve phenomena of this kind.

Over 90% of reported cases are members of the same family. Usually there is a dominant partner with fixed delusions who appears to induce similar beliefs in a dependent or suggestible partner, sometimes after initial resistance. The beliefs in the recipient may or may not be truly delusional. Generally the two people have lived together for a long time in close intimacy, often in isolation from the outside world. Once established, the condition runs a chronic course.

It is usually necessary to advise separation of the affected individuals. This may lead to resolution of the quasi-delusional state in the recipient; the original patient should be treated in the usual fashion for delusional disorder. For a review of shared delusional disorder, see Silveira and Seeman (1995).

Assessment of paranoid symptoms

The assessment of paranoid symptoms involves two stages—first, the recognition of the symptoms themselves, and secondly, the diagnosis of the underlying condition.

Sometimes it is obvious that the patient has persecutory ideas or delusions. At other times recognition of paranoid symptoms may be exceedingly difficult, and considerable skill is required by the interviewer. The patient may be suspicious or angry. They may be very defensive, say little, or speak fluently about other topics while steering away from persecutory beliefs or denying them completely. The psychiatrist should be tolerant and impartial, acting as a detached but interested listener who wants to understand the patient’s point of view. The interviewer should show compassion, but not collude in the delusions or give promises that cannot be fulfilled. When an apparently false belief is disclosed, considerable time and effort may then be needed to determine whether or not it meets the criteria for a delusion rather than an overvalued idea or other form of belief. This is of crucial diagnostic significance, as the presence of a delusion is likely to be the symptom upon which a diagnosis of psychotic disorder is based, whereas nondelusional thoughts which may be similar in content are consistent with a range of other diagnostic categories.

If delusions are detected, the next step is to diagnose the type of psychosis, based upon the diagnostic features of the disorders noted earlier in this chapter. It is also important to determine whether the patient is likely to try to harm the alleged persecutor. A full risk assessment is needed. This calls for close study of the patient’s personality, history of violence, and the characteristics of their delusions and any associated hallucinations. Hints or threats of homicide should be taken seriously. The doctor should be prepared to ask tactfully about possible homicidal plans and preparations to enact them. In many ways the method of enquiry resembles the assessment of suicide risk: ‘Have you ever thought of doing anything about it?’, ‘Have you made any plans?’ and ‘What might prompt you to do it?’

The assessment of dangerousness is discussed further in Chapter 24.

Treatment of paranoid symptoms and delusional disorder

General principles

Management of paranoid symptoms and delusional disorder is frequently difficult. The patient may be suspicious and distrustful, believing that psychiatric treatment is intended to harm them. Alternatively, they may regard their delusional beliefs as justified, and therefore see no need for treatment. Considerable tact and skill are needed when dealing with such patients, not only to encourage them to describe their symptoms fully as discussed above, but also to persuade them to accept treatment. Sometimes treatment can be made acceptable by offering to help non-specific symptoms such as anxiety or insomnia, or by pointing out the harmful consequences of the beliefs. Thus a patient who believes that he is surrounded by persecutors may agree that his nerves are being strained as a result, and that this needs treatment.

A decision must be made as to whether to admit the patient for inpatient care. This may be indicated if there is a significant or immediate risk of violence to others, or of suicide. When assessing such factors, it is important to consult other informants and obtain a history of the patient’s behaviour. If voluntary admission is refused, compulsory admission may be justified in order to protect the patient or other people, although this is likely to add to the patient’s resentment.

Drug treatment

Paranoid symptoms in delusional disorder are treated with antipsychotic drugs just as in other psychoses, although there are few randomized trial data to guide decision making (Manschreck and Khan, 2006; Lepping et al., 2007). Pimozide was advocated as the antipsychotic of choice for monosymptomatic hypochondriacal psychosis (delusional disorder, somatic type in DSM-IV) and pathological jealousy (Munro, 2009), and remains widely used (e.g. Lepping et al., 2010). However, the assertion is not supported by good evidence (Rathbone and McMonagle, 2007), and the cardiotoxicity of pimozide should also be taken into account. In general, any high-potency, non-sedating antipsychotic is suitable (e.g. risperidone), always starting with a low dose. Signs of improvement, notably a decrease in preoccupation with the delusion(s) and a reduction in agitation, may be seen within a few days. The importance of establishing a good therapeutic relationship in order to improve collaboration with treatment has already been emphasized.

With regard to the delusional form of body dysmorphic disorder, some data suggest that SSRIs rather than antipsychotics should be used as first-line treatment, with antipsychotic augmentation for those patients who do not respond (Phillips, 2004). The role of antidepressants in other delusional disorders remains unclear, although they are often used at some stage in treatment, reflecting the frequency of comorbid depressive symptoms, and their emergence during treatment. The risk of suicide should be monitored regularly.

Psychological treatment

Patients with paranoid symptoms require support, encouragement, and reassurance. This form of non-specific psychological treatment is an integral part of management, and essential if the patient is to be persuaded of the benefits of more targeted interventions. Of the latter, drugs are the mainstay of treatment, but specific psychological therapies may have a role, too. In particular, cognitive therapy, as used for the treatment of delusions in schizophrenia, may be worth trying if a sufficiently good therapeutic rapport exists. Interpretative psychotherapy and group psychotherapy are unsuitable, because suspiciousness and hypersensitivity may easily lead the patient to misinterpret what is being said.

Prognosis of delusional disorder

There are no reliable data on long-term outcome. Clinical impression suggests that the prognosis in delusional disorder is poor, although Munro (2009) claims that in patients who are compliant with medication, recovery occurs in 50% of cases, with substantial improvement in a further 30%. In some patients, medication can be reduced or stopped without ill effects, while in others (probably the majority) delusions recur rapidly on discontinuation, and treatment must be maintained for prolonged periods. This issue can be judged only by a careful clinical trial with regular monitoring of the patient’s mental state, and it requires discussion with the patient of the risks and benefits of long-term medication.

Further reading

Enoch MD and Ball HN (2001). Uncommon Psychiatric Syndromes, 4th edn. Edward Arnold, London. (Fascinating descriptions of many delusional disorders, and other uncommon and eponymous psychiatric syndromes.)

Hirsch SR and Shepherd M (eds) (1974). Themes and Variations in European Psychiatry. John Wright, Bristol. (See the following sections: E Strömgren, Psychogenic psychoses; R Gaupp, The scientific significance of the case of Ernst Wagner and The illness and death of the paranoid mass murderer schoolmaster Wagner: a case history; E Kretschmer, The sensitive delusion of reference; H Baruk, Delusions of passion.)

Lewis A (1970). Paranoia and paranoid: a historical perspective. Psychological Medicine1, 2–12. (A searching and scholarly review of the origin and development of the term paranoid and related concepts.)

Munro A (1999) Delusional Disorders. Cambridge University Press, Cambridge.