Psychiatrists make a distinction between the milder paranoid personality
disorder and the more debilitating delusional (paranoid) disorder.                            The hallmark of this disorder is the presence of a persistent,
non-bizarre delusion without symptoms of any other mental disorder.

Delusions are firmly held beliefs that are untrue, not shared by others in
the culture, and not easily modifiable. Five delusional themes are
frequently seen in delusional disorder. In some individuals, more than one
of them is present.

-- Ruth is a clerk typist who is efficient and helpful. Her employers and
co-workers value her contribution to the office. But Ruth spends her
evenings writing letters to State and Federal officials. She feels that God
has opened her mind and given her the cure for cancer. She wants some
leading treatment center to use her cure on all its patients so that the
world can see she is right. Many of her letters go unanswered, or she
receives noncommittal replies that only make her feel that no one understands
that she can save all cancer patients if only given the chance. When one of
her letters is answered by an employee of the official to whom she wrote, she
is sure that the official is being deliberately kept unaware of her knowledge
and power. Sometimes she despairs that the world will ever know how
wonderful she is, but she doesn't give up. She just keeps writing. Ruth
suffers from one of the delusional disorders, grandiose delusion.

The most common delusion in delusional disorder is that of persecution.
While persons with paranoid personality might suspect their colleagues of
joking at their expense, persons with delusional disorder may suspect others
of participating in elaborate master plots to persecute them. They believe
that they are being poisoned, drugged, spied upon, or are the targets of
conspiracies to ruin their reputations or even to kill them. They sometimes
engage in litigation in an attempt to redress imagined injustices.

Another theme seen frequently is that of delusional jealousy. Any sign--even
a meaningless spot on clothing, or a short delay in arriving home--is
summoned up as evidence that a spouse is being unfaithful.

Erotic delusions are based on the belief that one is romantically loved by
another, usually someone of higher status or a well-known public figure.
Individuals with erotic delusions often harass famous persons through
numerous letters, telephone calls, visits, and stealthy surveillance.

Persons with grandiose delusions often feel that they have been endowed with
special powers and that, if allowed to exercise these powers, they could cure
diseases, banish poverty, ensure world peace, or perform other extraordinary

Individuals with somatic delusions are convinced that there is something very
wrong with their bodies--that they emit foul odors, have bugs crawling in or
on their bodies, or are misshapen and ugly. Because of these delusions, they
tend to avoid the society of other people and spend much time consulting
physicians for their imagined condition.

Whether or not persons with delusional disorder are dangerous to others has
not been systematically investigated, but clinical experience suggests that
such persons are rarely homicidal. Delusional patients are commonly angry
people, and thus they are perceived as threatening. In the rare instances
when individuals with delusional disorder do become violent, their victims
are usually people who unwittingly fit into their delusional scheme. The
person in most danger from an individual with delusional disorder is a spouse
or lover.


U.S. Department of Health and Human Services
Public Health Service
National Institutes of Health
National Institute of Mental Health