Delusional disorder: causes, symptoms, diagnosis, treatment

Delusional disorder is characterized by delusional ideas (false beliefs) close to everyday life, which persist for at least 1 month, in the absence of other symptoms of schizophrenia.

In the literature on the relationship between mental disorders and crime, especially violent crime, delusional disorders are often considered together with schizophrenia, and therefore the results related to schizophrenia can be applied to delusional disorders. The above results related to delusional disorders are of particular value.

Delusional disorder differs from schizophrenia in that delusions predominate in the absence of other symptoms of schizophrenia. Delusional ideas appear outwardly realistic and concern situations that may occur, such as stalking, poisoning, infection, long-distance love, or deception by a spouse or loved one.

Unlike schizophrenia, delusional disorder is relatively rare. Onset is usually in middle or late adulthood. Psychosocial functioning is usually not impaired, as in schizophrenia, and impairments are usually directly related to the delusional plot.

When delusional disorder occurs in elderly patients, it is sometimes called paraphrenia. It can coexist with mild dementia. The physician must be careful when examining elderly patients with mild dementia to distinguish between delusional ideas and credible information about abuse by others towards the elderly person.

Diagnostic guidelines for delusional disorder are provided in ICD-10. In it, the term "delusional disorder" has replaced the previously used term "paranoid disorder." These disorders include persecutory subtypes, litigious paranoia, and what Mullen calls passion disorders (erotomania and pathological jealousy). People with these disorders rarely seek psychiatric help, but they come to the attention of the judicial services when the commission of a crime entails a court decision to forensic psychiatric examination in isolation from society. Beliefs labeled as "delusional" exist on a continuum with normal emotions and beliefs. This is especially true of morbid jealousy, in which overvalued ideas are imperceptibly organically intertwined with delusions. Delusional disorders can act as primary disorders, but can also be a symptom complex within another disorder, such as schizophrenia.

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Symptoms of delusional disorder

Delusional disorder may develop in the context of an existing paranoid personality disorder. In such individuals, persistent mistrust and suspicion of others and their motives begins in early adulthood and continues throughout life. Early symptoms may include a sense of being exploited, concerns about the loyalty and creditworthiness of friends, a tendency to read threatening meanings into unimportant statements or events, persistent resentment, and a readiness to react to slights.

There are several types of delusional disorder. In the erotomanic variant, the patient believes that another person is in love with him. Often, attempts to contact the object of delusional ideas are observed through phone calls, letters, surveillance, or stalking. People with this variant of the disorder may have conflicts with the law because of their behavior. In the variant with ideas of grandeur, the patient believes that he is talented or that he has made an important discovery. In the variant with ideas of jealousy, the patient believes that his spouse or loved one is cheating on him. These ideas are based on incorrect conclusions based on dubious evidence. A threat of physical attack may pose a significant danger. In the variant with ideas of persecution, the patient believes that he is being followed, harmed, and harassed. The patient may make repeated attempts to achieve justice by going to court and other government agencies, and also resort to violence as retaliation for the alleged persecution. In the somatic variant, delusional ideas are associated with bodily functioning, i.e. the patient believes that he has a physical defect, parasites, or an odor.

Diagnosis depends largely on clinical evaluation, obtaining a detailed anamnestic information, and ruling out other specific conditions associated with delusions. An assessment of the dangerousness, especially the degree to which the patient is willing to act on his or her delusions, is essential.

Delusional disorder associated with passion: pathological jealousy and erotomania

This group of disorders is comprehensively considered by Mullen. The core of the conviction in the case of morbid jealousy is formed by the subject's idea of infidelity to him/her. This idea dominates in thinking and actions and reaches a pathological level. Jealousy is a normal phenomenon, and its acceptance in society is partly due to the ethnocultural characteristics of the population. Mullen suggests the presence of a continuum from the degree of deep conviction in normal people - to overvalued ideas and further - to delusional ideas, characteristic of both morbid jealousy and erotomania. In studies of women - victims of domestic violence, it was found that an important cause of violence is the jealousy of the partner. Usually, it is the partners who suffer from attacks, while imaginary rivals rarely become victims. According to modern concepts, in addition to physical attacks, partners of people suffering from pathological jealousy can experience severe psychological distress, including post-traumatic stress disorder.

Erotomania is characterized by a morbid conviction of being in love with another person. Mullen suggests three main criteria:

• The belief that love is mutual, despite the fact that the supposed “lover” does not show it in any way.
• The tendency to reinterpret the words and actions of the object of attention in order to maintain an existing belief.
• Loaded with supposed love, which becomes the center of the subject's existence.

Moreover, the subject does not necessarily believe that his love is mutual (morbid infatuation to the point of madness). Like morbid jealousy, erotomania can act as part of another disorder, usually schizophrenia and mood disorders. The difference between subjects suffering from schizophrenia and cases of "pure" erotomania is that the object of their love or passion can change over time, as well as the presence of a more pronounced sexual element. The objects of attention of erotomaniacs are usually from their immediate environment, although the media likes to talk about cases with famous people, movie stars, etc. There is a high probability of becoming a victim of an erotomaniac among doctors, including psychiatrists, who are engaged in providing assistance to vulnerable people.

According to Mullen, erotomanic disorders are almost inevitably accompanied by stalking. Stalking involves a determined attempt to establish contact or communicate with the object of the stalker's attention. If the attempt at contact fails or is resisted, then threats, insults, and intimidation follow - either through direct contact or through communication (by mail, telephone, etc.). Menzies et al. report overt sexual intimidation or assault in a group of male erotomaniacs studied. Both Mullen & Pathe and Menzies et al. note high levels of threats and assaults among the stalkers they studied, although both populations were forensic, i.e., with a preponderance of the actual risk of attack. Victims of stalking can suffer greatly from repeated and unpredictable interference in their lives by stalkers. Many of them limit their social life, change jobs, and in extreme cases, even move to another country to get rid of the annoying attention.

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Prognosis and treatment of delusional disorder

Delusional disorder does not usually result in significant impairment or personality change, but delusional symptoms may gradually progress. Most patients can remain able to work.

The goals of treatment for delusional disorders are to establish an effective doctor-patient relationship and to eliminate the consequences associated with the illness. If the patient is considered dangerous, hospitalization may be necessary. There is insufficient evidence to support the use of any specific drug, but antipsychotics have been shown to reduce symptoms. The long-term treatment goal of shifting the patient's interests away from delusional ideas and toward more constructive ones is difficult to achieve but reasonable.

Medical and legal aspects of delusional disorder

The remarks concerning the medical and legal aspects of schizophrenia are equally applicable to patients with delusional disorders. As for the group of patients with delusional disorder, which manifests itself through morbid jealousy or erotomania, there are some peculiarities.

Where the cause of jealousy is a delusional disorder, the underlying mental illness may serve as the basis for recommendations for psychiatric treatment or a defense in cases of homicide on the grounds of diminished responsibility. Where jealousy is not delusional but neurotic in nature, the medico-legal aspects are far less clear. Thus, there may be a personality disorder that falls under the category of "psychopathic disorder." Other disorders that may be classified as mental illness may be present. However, excessive jealousy in the absence of an underlying illness cannot be used as a defense on medical grounds.

In delusional jealousy, the security regime of psychiatric treatment must be approached very carefully. The persistent nature of this disorder and its potential danger are well known. The patient must be carefully assessed for his or her willingness to cooperate with the therapist, and the risks of absconding and committing a violent crime must be assessed. If the subject is known to be uncooperative, has a history of violence against his or her wife, and has run away, then he or she should initially be treated in a high-security facility. Treatment may not be easy. Medication (antipsychotics or antidepressants) and cognitive therapy offer the greatest chance of improvement.

There is currently increasing attention to the medico-legal aspects of stalking. In these cases, psychiatrists may be called upon to testify in court about the harm caused to the victim of stalking, in the same way that a general practitioner is called upon to describe the harm caused to a person who has suffered a physical attack. This gives rise to charges of "grave bodily harm" (GBH) of a psychological nature. A psychiatrist may also be called upon to work with the offender. As with morbid jealousy, the treatment of morbid love or passion is difficult and the results are unpredictable. Given the persistence of these disorders and the tenacity with which the subjects cling to their beliefs, the only possible defence against stalkers may be their treatment and support by the mental health system. It is likely that in the future there will be an increasing demand for psychiatric, and especially forensic psychiatric services, to be involved in developing recommendations for the courts and for possible treatment of stalkers.