Delusional Disorder

Delusional disorder is a psychiatric condition in which a person has non-bizarre delusions. A delusion is a firmly held belief about something which is not based in reality. The person continues to hold the belief despite evidence or proof to the contrary, and even though no one else has that belief.

Delusions are classified as bizarre or non-bizarre. Bizarre delusions involve things which are completely implausible. For example, a person believing aliens have surgically removed his heart and replaced it with an alien heart. Non-bizarre delusions, on the other hand, involve things which could actually happen, such as having a serious illness, or being followed by FBI agents.

Delusions typically have a theme

The most common delusional themes are:

delusions that someone (usual of a higher social status) is in love with them
delusions that s/he has exceptional or special knowledge, power, worth, or identity; or, that s/he has a special relationship to someone famous or a deity
delusions that his/her spouse or partner has cheated on him/her
delusions that someone is harassing, spying on, ridiculing, or chasing him/her; or trying to harm him/her in some way
delusions about having a physical defect or health condition
delusions which involve two or more of the above themes, but no particular theme is dominant

Additional Features and Hallucinations

A person with delusional disorder may also have hallucinations. If the hallucinations are auditory or visual in nature, they aren’t prominent. However, they may have prominent olfactory (smell) or tactile (touch) delusions that are related to their delusions. For example, a person who has the delusion that s/he is pregnant may also have the tactile delusion that s/he can feel the baby kicking.

Aside from situations or things which relate directly to or are impacted by the delusion itself, the individual is usually able to function adequately and doesn’t act in ways which are odd or bizarre like someone who is schizophrenic.

With delusional disorder, the illness is not caused by a medical condition or a substance, such as drugs, alcohol or medication. Also, it is important to determine that the belief which is considered delusional is not a normal part of the person’s religion or culture.

Other features and issues

Delusional disorder usually strikes later in life, typically middle age or beyond. However, it does occasionally occur earlier.

It is not uncommon for individuals with this disorder to have “ideas of reference”. Ideas of reference occur when the person believes random happenings (e.g. a song playing on the radio) has special significance for him/her. Also, a person with this disorder often becomes depressed angry or irritable in reaction to his/her delusions. S/he may become enraged or violent as a result of the delusion if the them is one of jealousy or persecution.


Delusional disorder can be difficult to treat. Since the person is firmly convinced the delusion is real, s/he does not believe there is something wrong with him/her and will often be resistant to treatment. Without insight, psychotherapy may have limited effectiveness but it can be helpful to some degree. Atypical antipsychotic medications are often prescribed. Hospitalization may be required if the disorder causes the individual to be a risk to himself/herself or to others.

written by Dr. Cheryl Lane, PsyD