What is Delusional Disorder?

Delusional Disorder is a serious condition where a person experiences a loss of contact with reality. This is called psychosis and it takes the form of particular types of altered beliefs or delusions.

This type of psychotic illness is rare, seen only in about one in every thousand people. It tends to occur in middle or later life, although occasionally it begins at a younger age. There is no difference between men and women in the frequency of its occurrence.

What are the symptoms of Delusional Disorder?

The essential symptom of this condition is the delusions themselves. These delusions are beliefs that seem quite real to the person, but are not shared by those around them. Over time the person may become very preoccupied by the belief/s. The beliefs in general are things that may appear possible, such as:

It is important for mental health professionals to be clear that the beliefs are not acceptable or 'normal' within the person's culture and/or religion.

Risk factors for people with Delusional Disorder

The main issues are:

What causes Delusional Disorder?

As with all psychotic conditions, the specific cause of delusional disorder remains unknown.  What is currently known is that:

How is Delusional Disorder diagnosed?

There is no medical test that can diagnose delusional disorder. It is diagnosed by the presence of altered or unusual belief in a person who has no other prominent symptoms of psychosis, and who continues to cope with everyday activities and relationships. For this reason it is very important for a health professional to get a full understanding of the difficulties a person has had, from both the person and their family/whanau or others who know them well.

How is Delusional Disorder treated?

Treatment of delusional disorder involves a number of strategies that need to be tailored to meet the needs of the individual. The main components are:

Medication: Antipsychotic medications are the main group of medications used according to individual need and symptoms. Other medications such as tranquilizers and antidepressants may also be of value in treating mood swings and/or depression. When they have been established for some time, the delusions may respond poorly to treatment with antipsychotic medication but may respond to psychotherapy.

Psychosocial: These are non-medical "treatments" that address the person's thinking, behaviour, relationships and environment. Sometimes Cognitive Behavioural Therapy (CBT) may be used to help people learn psychological means to overcome persistent symptoms.

Counselling: This may involve some techniques used in psychotherapy but is mainly based on supportive listening, practical problem solving and provision of information.

Delusional Disorder can be effectively treated and people can recover, however, the earlier effective treatment is started, the better are the chances of recovery.

The main focus of treatment and care for people with delusional disorder is within the community.  Inpatient or hospital care may be used in those situations where the level of a person's symptoms and crisis may endanger their own or another's safety.

What are the side effects of medication?

The degree of side effects will depend largely on the dosage prescribed and the ability of the body to absorb the medication. Some side effects are normal, however if you have any concerns about side effects, do discuss these with your doctor. The doctor may be able to reduce the dose or medication or change to a medication that suits you better.

For more information click below

Mental Health Foundation - NZ


Like Minds Taranaki gratefully acknowledges the financial support of this website by the Ministry of Health

Feedback is always welcome
Like Minds Taranaki, 06-759-0966, email:

or on our Facebook page at: