Causes & Effects of Delusional Disorder

At San Jose Behavioral Health, we believe education is an important first step in the effort to manage delusional disorder. Understanding the signs, symptoms, and effects of delusional disorder can help you get the right type and level of care for yourself or a loved one.

Understanding Delusional Disorder

Learn About Delusional Disorder

Individuals with delusional disorder can have difficulty identifying reality, will believe things that are not true, and will hold onto those false beliefs even in the face of evidence to the contrary. Delusional disorder can be diagnosed if the person experiences delusions for more than a month that do not stem from another physical or mental health condition. The majority of delusional disorder cases impact daily living for an individual, but does not necessarily prevent that individual from functioning within society.

This mental health condition can come in a variety of forms. One form of delusion is called erotomanic type, which happens when an individual believes that a specific person is in love with him or her. Jealous delusions are beliefs that a partner is unfaithful, and grandiose delusions occur when an individual believes that he or she has an impeccable talent or is famous. Somatic delusion, a type of delusion involving the body, makes the individual feel like the body is invaded by illness, outside forces, or foreign organisms like insects. Persecutory delusions are beliefs that he or she is being attacked or plotted against by others.

Delusional disorder can have serious effects and complications on a person’s life, but treatment can help an individual recover and manage this mental health condition.


Delusional Disorder Statistics

Based on Diagnostic and Statistical Manual of Mental Disorders, 0.2% of people experience a delusional disorder at least once in their lives. Men and women are of equal risk of developing this condition, though men have higher risk of developing jealous delusions.

Causes & Risks

Causes and Risk Factors of Delusional Disorder

Researchers have found that a person’s risk of delusional disorder is tied primarily to genetic factors. Consider the following:

Genetic: Schizophrenia and schizotypal personality disorder cases in the family increase individuals’ risk of  developing delusional disorder. Older people are also at a higher risk than younger people.

Risk Factors:

  • A family history of schizotypal personality disorder or schizophrenia
  • Older age

Signs & Symptoms

Signs and Symptoms of Delusional Disorder

As with any other mental health disorders, delusional disorder symptoms may vary from person to person, especially considering the nature of these delusions. The following are symptoms to look for in order to identify delusional disorder:

Behavioral symptoms:

  • Extensive antagonism, like filing frivolous lawsuits
  • Unusual or abnormal behavior, like attempting to remove nonexistent insects from the skin
  • Being aggressive to others or to a specific person

Cognitive symptoms:

  • Erotomanic delusion, or the belief that someone is deeply in love with the individual
  • Grandiose delusion, or the belief that the individual has achieved great things or is famous
  • Jealous delusion, or the belief that his or her partner is being unfaithful
  • Persecutory delusion, or the belief that someone is out to harm the individual
  • Somatic delusion, or body-related distress, such as feeling that the body has a foul smell or is being invaded by insects
  • One or more of these delusions combined

Psychosocial symptoms:

  • Persistent difficulty with socializing
  • Agitation or anger
  • Anxiety
  • Irritability

Lasting Effects

Effects of Delusional Disorder

Delusional disorder often still allows an individual to perform regular tasks. However, if a person has delusions that directly affect major areas of his or her life, such as a persecutory delusion that his or her supervisors are actively trying to harm him or her, this disorder can have a great effect on the individual’s personal life. Other possible negative effects of struggling with delusional disorder are:

  • Difficulty socializing and building relationships
  • Being withdrawn or isolation that is self-imposed
  • Relationship conflicts
  • Poor performance at work or school
  • Irritability
  • Job loss
  • Inability to manage finances
  • Struggles with legal matters
  • Violence or cruelty towards others
  • Self-inflicted injury, which is often done by the individual to address the delusions (e.g. somatic delusion)
  • Development or worsening of other mental health disorders

Thankfully, delusional disorder can be treated. Medication and therapy treatments offer a way to recover from delusional disorders, even if the delusions are severe and pose a hindrance to the individual.

I was not mentally healthy. Experiencing a myriad of mental health problems, my family admitted me to San Jose for help. Their treatment and team helped me find myself. Thank you San Jose.

– Venessa C.