Delusions

Some authors equate morbid jealousy with a delusional state (e.g. Reference Enoch and TrethowanEnoch & Trethowan, 1979) (Box 1). Reference ShepherdShepherd (1961) pointed out that the commonly used term ‘delusion of jealousy’ is a misnomer and that the key psychopathology is a delusion of (the partner's) infidelity. Associated beliefs may include the morbidly jealous subject's suspicion that he or she is being poisoned or given substances to decrease sexual potency by the partner, or that the partner has contracted a sexually transmitted disease from a third party, or is engaging in sexual intercourse with a third party while the subject sleeps. These are persecutory delusions, and the delusion of infidelity itself may be viewed similarly.

Delusions of infidelity may be the initial presentation of schizophrenia, or appear as new features within an established psychosis. Delusional jealousy is a subtype of delusional disorder as described by DSM–IV (American Psychiatric Association, 1994) and ICD–10 (World Health Organization, 1992). In these cases, delusions of infidelity exist without any other psychopathology and may be considered to be morbid jealousy in its ‘purest’ form. The delusions are expressed coherently and are elaborated thoughtfully and plausibly, in contrast to the bizarre associations characteristically made in schizophrenia. Memories are revised and reinterpreted and the partner's present actions are misinterpreted to produce an absolute conviction of repeated betrayal (Reference MullenMullen, 1991).

Affective disorders complete the functional illnesses associated with delusions of infidelity. Depression, with accompanying subjective feelings of inadequacy and failure, may give rise to delusional jealousy or it may follow its onset. It may be difficult to decide whether depression is primary or secondary (Reference Cobb and MarksCobb & Marks, 1979). In one study of morbid jealousy, depression was present in more than half of the patients (Reference Mullen, Maack, Farrington and GunnMullen & Maack, 1985).

Organic brain disorders may give rise to delusions of infidelity. In their series, Reference Mullen, Maack, Farrington and GunnMullen & Maack (1985) found that almost 15% of individuals with morbid jealousy had an organic psychosyndrome with which the jealousy appeared associated. Reference CobbCobb (1979) recorded that morbid jealousy may be present with all types of cerebral insult or injury.

Obsessions

In obsessional jealousy, jealous thoughts are experienced as intrusive and excessive, and compulsive behaviours such as checking may follow. Such patients recognise that their fears are without foundation and are ashamed of them (Box 2) (Reference ShepherdShepherd, 1961; Reference MooneyMooney, 1965; Reference Cobb and MarksCobb & Marks, 1979, Reference Bishay, Petersen and TarrierBishay et al, 1989; Reference Stein, Hollander and JosephsonStein et al, 1994). Egodystonicity (the distress caused by thoughts that are unwanted and viewed as contrary to conscious wishes) characteristically varies considerably between patients, and a continuum from obsessional to delusional morbid jealousy has therefore been suggested (Reference Insel and AkiskalInsel & Akiskal, 1986).

In a study of young adults, Reference Marazziti, Di Nasso and MasalaMarazziti et al(2003) identified a number of factors that, when taken to the extreme, distinguish normal from obsessional jealousy (Box 3).

Reference Mullen, Bluglass and BowdenMullen (1990) considered an obsessional disorder at the core of morbid jealousy to be a ‘true rarity’. Reference CobbCobb (1979) concluded that, although a distinction was occasionally difficult to make, the categories of ‘psychotic’ (delusional) and ‘neurotic’ jealousy contained similar proportions (each between one-third and one-half).

Overvalued ideas

Reference SimsSims (1995: pp. 17 & 368) raised the possibility that morbid jealousy could take the form of an ‘overvalued idea’ (Box 4), that is, an acceptable, comprehensible idea pursued by the patient beyond the bounds of reason. The idea is not resisted and, although it is not a delusion, the patient characteristically attaches utmost importance to investigating and maintaining the partner's fidelity at great personal disadvantage and to the distress of the partner.

Overvalued ideas of morbid jealousy are described in the paranoid personality disorders classification of DSM–IV and ICD–10.

The prevalence of this subtype of morbid jealousy is unknown, and it is likely that a substantial proportion of people with these traits never present to mental health services. It is probable that in some recognised cases, what is identified as an overvalued idea is underestimated and really represents a delusion.

Borderline personality organisation (Reference DuttonDutton, 1994) is an important potential predisposing condition in any form of morbid jealousy (Box 5). It may be especially so in individuals with a paranoid personality, which gives rise to overvalued ideas of infidelity.

Comorbidity

Comorbidity is usual in morbid jealousy, and the ‘pure’ forms are rare. The presence of various combinations of comorbidity with personality disorder, mental illness and substance misuse can produce a very complicated picture. For example, a person with a paranoid personality disorder may become preoccupied with and distressed by jealous overvalued ideas, develop a delusion of infidelity and turn to substance misuse in an attempt at self-medication.

Psychodynamic

Freud considered that delusional jealousy represented projected latent homosexuality, in terms of ‘I do not love him for she loves him’ (Reference Freud and StracheyFreud, 1922). Klein highlighted the rivalry between son (the jealous individual) and father (the supposed rival) in the Oedipus complex (Klein, quoted in Reference ShepherdShepherd, 1961). Reference SeemanSeeman (1979) suggested that the role of competitiveness is significant, along with projective mechanisms and identification with the rival.

Attachment theory has been advanced to explain male jealousy, anger and assaults against the female partner within intimate relationships (Reference Dutton, Saunders and StarsomskiDutton et al, 1994; Box 5). Insecurely attached individuals, especially those of the fearful and preoccupied type, may be at increased risk of becoming anxious about their partner's attachment to them. Insecure attachment style correlates strongly with borderline personality organisation.

Cognitive

Reference Enoch and TrethowanEnoch & Trethowan (1979) viewed a sense of inadequacy, oversensitivity and insecurity to be major predisposing factors in the development of morbid jealousy. In their cognitive formulation, Reference Tarrier, Beckett and HarwoodTarrier et al(1990) proposed that people with these characteristics tend to make systematic distortions and errors in their perceptions and interpretation of events and information, so that a precipitating event gives rise to faulty assumptions and provokes morbid jealousy. These ideas resemble those described by attachment theory, especially in the context of borderline or paranoid personality organisation.

Reference Docherty and EllisDocherty & Ellis (1976) documented three morbidly jealous men, each of whom, during adolescence, saw his mother engaged in extramarital sexual activity. Although the authors interpreted the morbid jealousy of these men in psychodynamic terms (relating to Oedipal issues), their suggestion for therapy to combat cognitive distortion is in line with cognitive–behavioural therapy.

Sexual dysfunction

It has also been suggested that morbid jealousy may arise in response to reduced sexual function. Reference CobbCobb (1979) drew attention to the elderly man whose waning sexual powers are insufficient to satisfy a younger wife. Reference VauhkonenVauhkonen (1968) described sexual dysfunction per se to be important, but whether this was considered to be primary or secondary is unclear. Reference Todd, Mackie and DewhurstTodd et al(1971) reported that real or imaginary hypophallism may give rise to feelings of inferiority and lead to the development of morbid jealousy.

Marital and social factors

In cultures in which partners are treated as possessions, jealousy is often considered to be a normal part of sexual relationships and it may therefore be seen as an understandable (although undesirable) explanation for marital tension. Gender-role behaviour in which the male partner is dominant and the female submissive, in which there is a sense of sexual ownership, is generally tolerated. In highly conservative cultures, any evidence of autonomous or independent activity by a partner may be interpreted as evidence of infidelity and punished. Jealousy in this context may be used to justify violence towards a partner who is perceived as unfaithful.

For these reasons, it is important to be sceptical about claims by patients who are violent towards their partners in the context of jealousy that their victims (usually female) have provoked or actively encouraged them to be jealous.

The possibility of significant mental disorder in the patient's partner should be considered. In one instance, as a husband's delusional jealousy was successfully treated, the wife developed a paranoid psychosis, which receded as the husband's jealousy returned (Reference TurbottTurbott, 1981). Abnormal jealousy in homosexual patients has also been described (Reference Gordon, Oyebode and MinneGordon et al, 1997). Economic depression has been associated with increased incidence of delusional jealousy (Reference ShepherdShepherd, 1961).

Associated alcohol and drug use

Alcohol misuse has a well-recognised association with morbid jealousy (Reference ShepherdShepherd, 1961). In two studies, morbid jealousy was present in 27% and 34% respectively of men recruited from alcohol treatment services (Reference Shrestha, Rees and RixShrestha et al, 1985; Reference Michael, Mirza and MirzaMichael et al, 1995).

Given the prevalence of harmful and dependent use of alcohol in the UK, these figures suggest that morbid jealousy is not rare.

Some authors consider alcohol to exacerbate existing morbid jealousy, but rarely to be a primary cause (Reference LangfeldtLangfeldt, 1961; Reference ShepherdShepherd, 1961; Reference CobbCobb, 1979). This is disputed by Reference Michael, Mirza and MirzaMichael et al(1995), who described 65 of 71 male subjects as developing morbid jealousy following, and presumably secondary to, alcohol dependence.

Amphetamine and cocaine use can give rise to delusions of infidelity that may persist after intoxication ceases (Reference ShepherdShepherd, 1961). One case report described a man prescribed dexamphetamine for adult attention-deficit hyperactivity disorder who developed morbid jealousy (Reference Pillai and KrayaPillai & Kraya, 2000).

A likely explanation for morbid jealousy that is present apparently only at times of intoxication is that it exists at other times but in an inhibited state. The disinhibition that accompanies intoxication results in its manifestation. The individual who turns to substance use may be attempting to cope with the symptoms of either borderline or paranoid personality organisation, with accompanying jealousy.

Confirmatory behaviours

Once suspicions regarding the partner's fidelity are established, they quickly become preoccupying. Overt behaviours to investigate suspicions and preoccupations are common and evident to all involved. They include interrogation of the partner, repeated telephone calls to work and surprise visits, stalking behaviour, or hiring a private detective to follow the partner. Jealous individuals may search the partner's clothes and possessions, scrutinise diaries and correspondence, and examine bed linen, underclothes and even genitalia for evidence of sexual activity. They may hide recording equipment to detect clandestine liaisons, and some go to extreme lengths, including violence, to extract a confession from their partner.

The accused partner is assumed to be guilty until evidence of innocence is found, but this cannot materialise. Heroic efforts to prove innocence or disprove guilt must fail, as irrational preoccupations cannot be refuted rationally (Reference ShepherdShepherd, 1961; Reference MooneyMooney, 1965; Reference SeemanSeeman, 1979).

Harm to self

Suicidal ideation is not uncommon in morbid jealousy, given the association with depression and substance misuse. Aggressive challenging of the partner may be followed by intense remorse during which suicidal action may occur (Reference ShepherdShepherd, 1961). In a UK population, Reference MooneyMooney (1965) found that 20% of morbidly jealous individuals had made suicide attempts. Where jealousy gives rise to fatal violence against the partner, this may be followed by suicide (Reference WestWest, 1965).

Risk to others

Violence may occur in any relationship marred by jealousy, although the risk may be greater in morbid jealousy (Reference Mullen, Bluglass and BowdenMullen, 1990). Culturally, jealousy may be used to justify violence towards partners, and in some courts of law it can even be used as the basis of a provocation defence. Victims of homicide are most likely to be current or ex-partners; this is true for both male and female perpetrators.

Reference DellDell (1984) concluded that ‘amorous jealousy/possessiveness’ accounted for 17% of all cases of homicide in the UK. Reference MowatMowat (1966) reported on 110 morbidly jealous subjects who had killed or committed serious assaults and been admitted to a British forensic psychiatric facility. In 94 cases, the victim had been the partner. In Reference MooneyMooney's (1965) series, 14% of morbidly jealous individuals were considered to have made ‘homicidal attempts’, the majority against the accused partner.

Repeated denials of infidelity may provoke extreme anger and violence. Alternatively, the long-suffering partner, plagued by repeated cross-examination and accusations of infidelity, may yield and give a false confession, provoking a violent rage in the jealous individual.

Domestic violence is a common result of jealousy, normal or morbid. According to the British Crime Survey, 23% of women and 15% of men have been physically assaulted by their partners (Reference Mirrlees-BlackMirrlees-Black, 1999). Domestic violence is associated with increased risk of death at the hands of the perpetrator. It is also associated with morbid jealousy in the context of borderline personality organisation in males (Reference DuttonDutton, 1994).

Reference Mullen, Maack, Farrington and GunnMullen & Maack (1985) found in their UK series that more than half of morbidly jealous individuals physically assaulted their partner, although none had come to the attention of the criminal justice system. Morbidly jealous men were more likely to attack their partners than were morbidly jealous women and they tended to inflict more serious injuries.

In their US sample of 20 individuals with delusional jealousy, 19 of whom were male, Reference Silva, Ferrari and LeongSilva et al(1998) found that 13 had threatened to kill their spouse because of alleged infidelity – of these, 9 had actually attacked their spouse. Overall, 12 had harmed their spouse, 3 of them using a weapon. The presence of paranoid delusions and command hallucinations to injure the spouse were associated with violence, suggesting that individuals with delusional jealousy who perpetrate violence may be driven directly by psychotic phenomena. Alcohol consumption was also associated with a higher risk of assault.

Accusations may be made and violence directed towards a third party believed to be the partner's lover, the ‘paramour’ (Reference Tarrier, Beckett and HarwoodTarrier et al, 1990). Seven out of 110 victims of homicide or serious assault were supposed paramours in Reference MowatMowat's study (1966). More than 50% of the alleged paramours in Reference Silva, Ferrari and LeongSilva et al’s (1998) study of delusional jealousy were known to the subject. However, no serious threats of harm or incidents of violence were made against them.

The gender difference in physical assault against partners found by Reference Mullen, Maack, Farrington and GunnMullen & Maack (1985) is difficult to quantify because violence by women against men may be underreported. Similarly, given the problems in distinguishing accurately between delusions, obsessions and overvalued ideas, it is difficult to estimate the relative risk of interpersonal violence of each form. Nevertheless, psychotic drive in delusional jealousy seems to be a particularly important association, as it is generally in linking psychotic conditions and violent actions. Overall, morbid jealousy indicates a paranoid state of mind and therefore is likely to be associated with a high risk of violence.

Risk to children

Children in the household may suffer emotional and physical abuse as a result of the actions of a morbidly jealous parent. They may witness arguments and physical violence between their parents or be injured accidentally during assaults. They may be employed by the morbidly jealous partner to spy on a parent. They may even see a homicide or suicide in which a parent is the victim.

Other risks

Partners of morbidly jealous people may develop mental disorder, including anxiety and depression, or may turn to substance misuse (Reference Tarrier, Beckett and HarwoodTarrier et al, 1990). Reference VauhkonenVauhkonen (1968) described two cases in which jealousy became apparent only after the partner had made suicide attempts in response to persistent unreasonable accusations. Rarely, partners may respond violently themselves to repeated confrontations. Severe psychological damage to individuals, couples and families arising from morbid jealousy is discussed by Reference CobbCobb (1979).

Assessment

Assessment of morbid jealousy requires a wide-ranging approach (Box 6). Careful history-taking should be employed, and, if possible, both partners should be interviewed separately and together. The issue of jealousy should be approached tactfully, as the jealous individual may believe that the partner's alleged infidelity is creating the difficulties, not their own jealousy. It is important to complete a full psychiatric history and mental state examination, looking carefully at the phenomenology of the jealousy. It may be possible to distinguish between jealousy that is delusional, obsessional or an overvalued idea, and this may be significant in terms of risk. Evidence of associated mental illness and substance misuse should be carefully elicited. It is recommended that more than one interview be conducted to assess the marital relationship, and that a sexual and domestic violence history be taken from both partners, who should be seen separately as well as together.

Regarding risk, the issue of suicidal ideation should be raised with both partners. Enquiries about confrontations, arguments, threats and actual violence perpetrated by the jealous individual should be made, so that the risk of interpersonal violence, especially to the partner and any third party identified as a rival, can be assessed. The risk to children in the household should be considered, and protecting them is a paramount concern.

Initial considerations following assessment

It is wise to share information about risk with both partners. Consent should first be sought from the patient, unless the risk to another individual is serious and immediate, in which case confidentiality may be broken. All necessary steps should be taken to protect a potential victim: this may range from giving advice to that person to notifying the police. If there is a high risk of harm, the morbidly jealous individual should be admitted to hospital immediately. Child protection proceedings should be instituted if necessary.

If there is a history of violence, it should be made clear that physical abuse is unacceptable and illegal. Criminal and civil law (the Family Law Act 1996) provide protection against domestic violence, and victims may be advised to seek legal advice. Child protection proceedings should be initiated in accordance with the Children Act 1989 if there is cause to suspect that a child is suffering, or is likely to suffer, significant harm (Department of Health, 1999).

Treatment

A range of biological and psychosocial options are available for the management of morbid jealousy. These include medication, psychotherapy and hospital admission (Box 7).