DSM-IV-TR criteria

• A delusion develops in an individual in the context of a close relationship with another person or persons, who have an already established delusion.
• The delusion is similar in content to that of the person who already has an established delusion.
• The disturbance is not better accounted for by another psychotic disorder (e.g., schizophrenia) or a mood disorder with psychotic features and is not due to the direct physiological effects of a substance (e.g., drug abuse, medication) or a general medical condition.

Associated features

Shared Psychotic Disorder is a rare condition where a healthy person, also known as secondary in this situation, shares the delusions and false beliefs that the other person refuses to give up.

Also, this usually occurs in the face of contradictory facts of a more superior person, also known as primary in this situation that has the psychotic disorder. Delusions may occur and may be similar to the ones experienced by someone close who has a psychotic disorder.

However, the primary individual with this disorder generally will have delusions less bizarre than an individual with schizophrenia and the delusions are much more believable, making it easier for the secondary individual to believe the delusion.

Individuals with Shared Psychotic Disorder do not usually have unusual or odd behavioral issues. Secondary hallucinatory experiences occur less frequently and are less intense than primary hallucinatory experiences.

In two reported cases, the secondary experienced hallucinations while the primary did not.

Child vs. adult presentation

Other than the fact that Shared Psychotic Disorder tends to occur in relationships that are time-honored and resistant to change, which could include children and adults, there is little information regarding child vs. adult presentation or onset.

Gender and cultural differences in presentation

Since the 1650s, Shared Psychotic Disorder has been identified more frequently in women, reflecting the traditional submissive role of females in the family. Nevertheless, no confirmation of increased susceptibility of females exists today.

Both female and male secondaries are equally affected by female primaries.

Epidemiology

Rarely seen in clinical settings, it is argued that some cases of Shared Psychotic Disorder go without ever being diagnosed. If it is brought to clinical attention, it is the result of the primary person receiving treatment. The person with Shared Psychotic Disorder does not walk into a clinic alone.

Etiology

The cause of Shared Psychotic Disorder is unknown. However, several possible factors are believed to play roles in the development of Shared Psychotic Disorder. Some researchers believe that the disorder comes from a psychosocial perspective, as most of the individuals with the disorder have immediate relatives with psychiatric disorders. Additionally, family isolation and the presence of a dominant-submissive factor within a relationship affect the presence of this disorder.

Empirically supported treatments

Effective treatment of the secondary requires neuroleptics and separation from the primary.

There are three possible treatments for Shared Psychotic Disorder: psychotherapy, family therapy, and medication.

Psychotherapy can help the person with Shared Psychotic Disorder recognize the delusion and correct the underlying thinking that has become distorted. It also can address relationship issues and any emotional effects of a short-term separation from the person with a psychotic disorder.

Family therapy might focus on increasing exposure to outside activities and interests, as well as the development of social supports to decrease isolation and help prevent relapse. Family therapy also might help to improve communication and family dynamics.

Short-term treatment with anti-psychotic medication might be used if the delusions do not resolve after separation from the primary case. In addition, tranquilizers or sedative agents such as lorazepam or diazepam (Valium) can help alleviate intense symptoms, such as anxiety, agitation, and insomnia, which might be associated with the disorder.

Individuals with this disorder rarely seek treatment, though, and are usually only brought to clinical attention when the primary case receives treatment.