Delusional disorder is relatively rare—affecting 0.2 percent of the population, according to the DSM-5. Individuals diagnosed with delusional disorder have one or more delusions for at least one month. These fixed, false beliefs typically concern situations that can occur in real life (though there’s a specification in the DSM-5 for bizarre content).

For instance, individuals might think someone is trying to poison them or they’re suffering from a serious medical condition or their coworker is in love with them. The most common delusion is persecutory, where individuals believe that someone is spying on them, following them, or trying to harm them (or their loved one).

Individuals with delusional disorder aren’t functionally impaired, and their actions don’t appear bizarre or strange. In other words, aside from the delusion (and associated behavior), the person appears normal.

Delusional disorder is challenging to treat because individuals typically lack insight into their illness. That is, they don’t think they’re sick, so they seldom seek help or want treatment.

However, there are effective ways to treat this condition. Both medication and psychotherapy are valuable interventions. It’s common for delusional disorder to co-occur with other conditions, particularly depression and anxiety, so it’s critical for treatment to address these concerns, as well.

Psychotherapy

There’s limited research on psychotherapy for delusional disorder. Also, because individuals truly believe their delusions, it’s difficult to engage them in psychotherapy. Various resources have highlighted the challenges of establishing a therapeutic alliance between client and clinician.

In other words, individuals with delusional disorder often don’t trust therapists, so it’s tough to establish a positive, secure relationship.

Still, psychotherapy is valuable for treating delusional disorder—and is especially important because medication doesn’t decrease delusions for everyone. Cognitive behavioral therapy (CBT) seems to be the best studied intervention—and has explored everything from worry to sleep issues in individuals with delusions.

For instance, according to a 2015 article in The Lancet, an 8-week CBT intervention decreased worry and persecutory delusions, results that were maintained at follow up (24 weeks later).

Some research has found that reasoning biases—such as jumping to conclusions and belief inflexibility–may spark and perpetuate delusions (such as paranoia). Consequently, treatments are being developed to target these areas and appear to be promising. For instance, SlowMo is a digital therapy that helps individuals decelerate their thinking.

Metacognitive training (MCT) is another promising intervention that addresses reasoning biases and challenges the content of delusional beliefs. Both group and individual versions have been developed. According to a 2017 randomized controlled trial on individualized MCT, “Its main goal is to highlight the fallibility of cognition in general and encourage patients to reflect on their own thinking styles in relation to symptoms, but also to everyday life.”

CBT for psychosis (CBTp) is a collaborative, evidence-based therapy for schizophrenia, which treats delusions. According to Psychiatric Times, it includes using empathy and curiosity to explore how individuals are coping with their beliefs; identifying the origin of the delusion; and suggesting individuals pinpoint the benefits and downsides of their delusion, and evaluate the evidence for and against their delusion. A 2019 review noted that “It is geared towards achieving the person’s personal valued goal(s), with paramount importance being given to the therapeutic relationship and empowerment, maintaining the person’s self-esteem, and providing hope.”

Therapy also can focus on other symptoms and concerns that are interfering with the person’s life. For example, high rates of insomnia are found in individuals with persecutory delusions, and preliminary research has found that CBT for insomnia was effective.

Medications

The evidence on effective medications for delusional disorder is scarce. Currently, there are no randomized clinical trials, the gold standard for research. Available evidence consists of case reports, case series, and observational studies.

According to these sources, the first-line pharmacological treatment is antipsychotic medication. This includes both first- and second-generation antipsychotics (also known as typical and atypical antipsychotics). Some research suggests that first-generation antipsychotics are more effective than second-generation antipsychotics, while other research finds no difference.

Today, second-generation drugs are more commonly prescribed, because their side effects tend to be more tolerable.

Delusions don’t completely vanish with medication. According to UpToDate.com, “In our clinical experience, treatment of delusional disorder with antipsychotic medication does not result in the disappearance of delusions; rather, they become less important to the patient, or more tentatively accepted as true, permitting other more normal life pursuits to proceed.”

According to a 2015 article, when medication is prescribed, it’s vital to consider the person’s age, presence of co-occurring conditions, and drug interactions. For instance, the authors note that the typical antipsychotic pimozide (Orap), which used to be a first-line medication, might be best for younger individuals at a low dose, who aren’t taking any other medication, and receive QTc monitoring. An electrocardiogram is required before taking this medication. Pimozide is known to increase QT interval, which can increase cardiovascular risk, which is why it’s no longer considered a first-line treatment.

UpToDate.com noted that antipsychotic medication with the least number of side effects should be used, such as aripiprazole (Abilify) or ziprasidone (Geodon). Also, medication should be started at a low dose and increased gradually over several days or weeks to make sure it’s tolerable to the person.

It’s common for individuals with delusional disorder to take more than one medication. Typically, individuals take an antipsychotic drug along with an antidepressant.

Antidepressants may be prescribed to treat depression or anxiety. Some older case reports also found that selective serotonin reuptake inhibitors (SSRIs) and the tricyclic antidepressant clomipramine (Anafranil) may successfully treat somatic delusions.

Strategies for Loved Ones

Work with a specialist. One of the best things you can do is to see a therapist who specializes in treating individuals with psychotic disorders to learn how to successfully support your loved one. You might learn how to talk to your loved one when they bring up their delusion, encourage them to seek help, and/or encourage them to take their medication. (Unfortunately, individuals with delusional disorder tend to be hesitant about taking medication.)

One of the best things you can do is to see a therapist who specializes in treating individuals with psychotic disorders to learn how to successfully support your loved one. You might learn how to talk to your loved one when they bring up their delusion, encourage them to seek help, and/or encourage them to take their medication. (Unfortunately, individuals with delusional disorder tend to be hesitant about taking medication.) Learn as much as you can. Become an expert on delusional disorder. For example, check out this piece on Psych Central, which features 10 helpful strategies for helping someone who’s struggling with delusional thoughts, including expressing empathy, offering to seek therapy together, learning about cognitive distortions, and modeling reality testing. This piece on the National Alliance on Mental Illness, written by a woman who recovered from psychosis, also includes valuable tips on helping a loved one. This articulate piece is written by a man who’s been diagnosed with delusional disorder.

Become an expert on delusional disorder. For example, check out this piece on Psych Central, which features 10 helpful strategies for helping someone who’s struggling with delusional thoughts, including expressing empathy, offering to seek therapy together, learning about cognitive distortions, and modeling reality testing. This piece on the National Alliance on Mental Illness, written by a woman who recovered from psychosis, also includes valuable tips on helping a loved one. This articulate piece is written by a man who’s been diagnosed with delusional disorder. Seek out support. For instance, the Schizophrenia and Related Disorders Alliance of America (SARDAA) offers a family and friends support group every Tuesday at 7 p.m. EST., which you can access over the phone (and includes other resources). Schizophrenia.com offers online forums for family and friends.