Delusional Mental Health Disorders: Definition and Characteristics

An error occurred trying to load this video.

Try refreshing the page, or contact customer support.

Coming up next: Schizoaffective Disorder: Depression and Elevation

You're on a roll. Keep up the good work!

Take Quiz Watch Next Lesson
Your next lesson will play in 10 seconds
  • 0:06 Delusional Disorder
  • 1:20 Diagnosis
  • 3:23 Types of Delusional Disorder
  • 5:17 Lesson Summary
Save Save Save

Want to watch this again later?

Log in or sign up to add this lesson to a Custom Course.

Log in or Sign up

Speed Speed

Recommended Lessons and Courses for You

Lesson Transcript
Instructor: Natalie Boyd

Natalie is a teacher and holds an MA in English Education and is in progress on her PhD in psychology.

Delusional disorder is a rare psychotic disorder with many subtypes. In this lesson, we'll look at the hallmarks and diagnosis of delusional disorder. We'll also explore the many subtypes, and the symptoms of each.

Delusional Disorder

Audrey and Joe are friends. They met in the waiting room of their psychologist's office. They have similar problems, but are a little different. Audrey believes that aliens are after her. She can hear them talking, and sometimes, she even sees them staring at her.

Joe, on the other hand, believes that his wife is trying to poison him. He doesn't see or hear anything unusual, but he's convinced that she's going to kill him, even though there's lots of evidence that his wife is not planning on poisoning him.

Both Audrey and Joe suffer from delusions. A delusion is the persistent belief in something false, even in the face of evidence that it's not true. Audrey's delusion is that aliens are after her. Joe's is that his wife is trying to poison him.

Delusions are a symptom of many psychotic disorders. One rare psychotic disorder is delusional disorder. Delusional disorder involves having delusions that could happen in real life. For example, Joe's wife could poison him, so that is a delusion that could happen in real life. On the other hand, Audrey's delusion, that aliens are out to get her, is not considered to be possible in real life.


Besides delusions that could happen in real life, delusional disorder has another element that distinguishes it from most psychotic disorders: the absence of hallucinations. Remember Audrey? She hears and sees things that aren't there. These are hallucinations. Compare that to Joe, who doesn't see or hear anything unusual. He's not suffering from hallucinations.

Psychologists use a book called the Diagnostic and Statistical Manual of Mental Disorders, or DSM, to diagnose delusional disorder and other mental illnesses. In the DSM, there's a brief checklist for delusional disorder. We already know that Joe is having delusions that could happen in real life and that he's not suffering from hallucinations, so perhaps he has delusional disorder. Let's check Joe's symptoms against the checklist from the DSM.

  1. Non-bizarre delusions - These are the delusions that could happen in real life, so yes, Joe does have them.
  2. Absence of obviously odd behavior - Joe acts and functions normally, so yes, he has an absence of odd behavior.
  3. Absence of hallucinations or hallucinations that are infrequent - As we said before, Joe has no hallucinations, so we can check this one off, too.
  4. No memory loss, medical issue or drug use is responsible for the delusions - Joe doesn't have amnesia or another medical problem, and he doesn't take drugs or drink, so his delusions aren't because of those reasons.
  5. Any mood disorders do not last as long as the delusion - This, like number four, is about making sure that the delusions aren't part of another problem. Mood disorders are things like depression and bipolar disorder. Since Joe doesn't show signs of these, we can check this off.

Based on the criteria from the DSM, we can diagnose Joe with delusional disorder. Treatment usually involves antipsychotic drugs, though sometimes therapy is also used, particularly if the patient has even a little bit of doubt in their delusion.


Besides offering a checklist of symptoms, the DSM also identifies seven types of delusional disorder.

They are:

To unlock this lesson you must be a Member.
Create your account

Register to view this lesson

Are you a student or a teacher?

Unlock Your Education

See for yourself why 30 million people use

Become a member and start learning now.
Become a Member  Back
What teachers are saying about
Try it risk-free for 30 days

Earning College Credit

Did you know… We have over 200 college courses that prepare you to earn credit by exam that is accepted by over 1,500 colleges and universities. You can test out of the first two years of college and save thousands off your degree. Anyone can earn credit-by-exam regardless of age or education level.

To learn more, visit our Earning Credit Page

Transferring credit to the school of your choice

Not sure what college you want to attend yet? has thousands of articles about every imaginable degree, area of study and career path that can help you find the school that's right for you.

Create an account to start this course today
Try it risk-free for 30 days!
Create an account