Rare Mental Disorders: Causes, Symptoms, and Treatments

Rare mental disorders like Capgras syndrome, Fregoli delusion, and clinical lycanthropy can profoundly disrupt reality perception. Explore causes, symptoms, and treatments.

Mental health problems are very common in the United States, affecting millions. About 50% of Americans will experience a mental disorder at some point.1 Worldwide, roughly 13% of people deal with mental health issues, which is about 971 million individuals.1

Depression is the third leading cause of hospital stays for people between 18 and 44 in the U.S. Yet, conditions like schizophrenia and bipolar disorder are more known. There are mental health issues so uncommon that professionals might not see them often. This piece delves into five rare mental disorders, discussing their origins, symptoms, and how they’re treated.

Key Takeaways

  • Rare mental disorders can have bizarre and unusual symptoms that even experts find hard to explain.
  • Dissociative Identity Disorder (DID) is characterized by a person having more than two distinct identities due to repeated childhood trauma.2
  • Obsessive-Compulsive Personality Disorder involves a chase for perfectionism and control, leading to repetitive rituals and significant distress.2
  • Histrionic Personality Disorder (HPD) is known for dramatic behavior, self-centeredness, and inappropriate flirtatious behavior, impacting interpersonal relationships.2
  • Rare disorders like Autocannibalism, Alice in Wonderland Syndrome, and Alien Hand Syndrome have severe and debilitating symptoms.2

Understanding Rare Mental Disorders

Mental disorders change how we behave and can impact our lives. They are often treatable with the right medicine and therapy.1 While we talk a lot about common mental illnesses, there are some very rare ones. These rare ones can show strange symptoms that are tough to explain, even for experts.1

Prevalence and Impact

About 13% of people worldwide have a mental disorder.1 Things like Alice in Wonderland Syndrome usually happen to young adults. But they can also occur in adults. It’s important to know about these rare conditions so we can give the right help.1

Recognizing Unusual Symptoms

Knowing the unique signs of rare mental disorders is crucial. This helps to correctly diagnose and treat people. Conditions such as Dissociative Identity Disorder (DID) and Obsessive-Compulsive Personality Disorder have odd behaviors.2 Keeping up-to-date on rare mental health issues can assist doctors. It also helps the public recognize and understand these conditions.

Cultural Syndromes

Cultural syndromes cover psychological and physical issues that affect certain groups. These issues show unique behavior, experiences, and beliefs. They come from the deep values and worldviews in a community.3 According to the American Psychiatric Association, these are behavior patterns linked to specific areas. Khyâl cap and Kufungisisa are two examples that connect culture with mental and physical health.

Khyâl Cap or “Wind Attacks”

Among Cambodians, both in the US and Cambodia, there’s a special issue known as Khyâl cap.4 It feels like a panic attack, with symptoms such as feeling dizzy, having fast heartbeats, and struggling to breathe. People also feel anxious and their body reacts in a certain way.4

Kufungisisa or “Thinking Too Much”

The Shona people in Zimbabwe face Kufungisisa, literally “thinking too much.”4 Many see this as harmful for health, leading to problems like headaches.4 These syndromes are ways to show psychological or social issues that are common in some cultures.

cultural syndromes

Delusional Disorders

Delusional disorders are mental health conditions. They lead to persistent, irrational beliefs not rooted in reality. People may believe they can turn into animals or see loved ones as impostors.5

Clinical Lycanthropy

Clinical lycanthropy is a rare delusional disorder. Those affected think they can turn into animals, especially wolves or werewolves.5 They act like these animals during these delusions. It’s a part of delusional misidentification syndrome. This group includes disorders where beliefs about people, objects, or events are wrong.5

Capgras Syndrome

Capgras syndrome makes patients think a close one is an impostor. This often affects spouses, friends, or family.5 It’s found in some with schizophrenia, dementia, or epilepsy, and after brain injuries.6

The reason behind Capgras syndrome is not fully clear. However, experts think it’s due to a split between the emotional and thinking parts of recognizing faces.

Dissociative Disorders

Dissociative disorders make you feel far from yourself or the world. This leads to seeing things in a different way. For example, in dissociative identity disorder (DID), a person might act like they are someone else.

This disorder can make you forget things like personal info or big events in your life. It can feel like different people live in the same body. They might not remember what each personality does. This is called “alters” or alternate personalities.7

Depersonalization/Derealization Disorder

People with depersonalization/derealization disorder feel like they’re watching themselves from the outside. Or, they may think everything around them isn’t real.7 These feelings can start in childhood and often happen before someone turns 20.

They differ from temporary feelings of not being in touch with reality. These temporary feelings can come from medication, drug use, or physical and mental health issues.7

7 Dissociative amnesia has three types: localized, selective, and the rarest, generalized amnesia. Researchers are studying how the brain works differently in these states. Certain memory parts show activity, but they don’t seem to be connected with other brain areas that help think and plan.7

8 DID affects about 1.5% of people all over the world.8 The severe forms, like severe DID, are found in 1% to 1.5% of people globally.8 Overall, 1% to 5% of the world’s people have these disorders. DID is seen in about 1.5% of people on the planet.8

8 It can take from 5 to 12.5 years for doctors to diagnose someone with DID.8 People with DID are more likely to hurt themselves or try to commit suicide. It’s been seen in many countries. People might describe it as being taken over by something outside them, like demons.8

8 Those diagnosed with DID often hurt themselves. They might also misuse drugs and alcohol.8

rare mental disorders

Many know about depression and bipolar disorder. But there are also extremely rare mental conditions that baffle experts.9 These mysterious disorders often seem more like they’re from a fantasy or horror world than reality. Yet, they are real and can greatly impact people’s lives.9 Knowing about these rare disorders is crucial for helping those who suffer.

Anxiety and depression are common mental health problems. They affect a lot of people.9 However, some of the rarest conditions have symptoms that seem illogical. They make us rethink what we know about the human mind.10 Conditions like delusional disorders and dissociative identity disorder show the deep complexity of our minds.

Exploring rare mental disorders reveals conditions that mix real life with fantasy.2 For instance, Dissociative Identity Disorder (DID) makes people have different identities. Obsessive-Compulsive Personality Disorder (OCPD) leads to a never-ending quest for perfection.2 Disorders like Histrionic Personality Disorder (HPD) highlight our mind’s rich diversity.

Rare mental disorders challenge our knowledge of mental health. They push us to keep researching and being aware.10 By understanding and supporting those with these rare conditions, we can improve treatment.10 Exploring the world of rare disorders is both fascinating and essential for understanding the human mind.

Rare Mental DisorderPrevalenceKey Characteristics
Delusional Disorder10 Affects .02% of the general populationPersistent delusional beliefs, often involving themes of persecution
Conversion Disorder10 Impacts 2-5 out of every 100,000 individualsNeurological symptoms like paralysis or blindness without a physical cause
Selective Mutism10 May develop in .03-.79% of the populationInability to speak in certain social settings, even though able to speak elsewhere
Postpartum Psychosis10 Affects 5 out of 1,000 mothersSevere mental episodes with psychotic symptoms after childbirth
Substance-Induced Anxiety Disorder10 Can happen in .002% of the population in 12 monthsAnxiety and panic from using or stopping substances
See also  Intervention for Mental Health: Effective Strategies

Hoarding and Self-Neglect

The Diogenes Syndrome is mostly seen in the elderly. They collect lots of things and don’t care for themselves well.11 It’s named after an ancient philosopher who lived simply. Unfortunately, those with this syndrome keep too much stuff and lose interest in their own health.11

Diogenes Syndrome

This syndrome is usually found in people over 60.12 They might not live in clean places or take good care of themselves.11 Not knowing how bad things are, they often live on their own.11

It often comes along with other problems like depression and anxiety.13 People with this syndrome keep collecting things and may not realize they need help.13 They don’t seem to stress about the condition they live in.13

Half the time, there’s no other mental illness with Diogenes syndrome.11 But sometimes, there are other mental health issues too.11 Some might also have dementia. This shows it could be linked to that as well.12 Yet, many cases happen without any big mental health history.12

Doctors may use different medicines to help treat this syndrome, much like with anxiety or depression.11 In one case, the patient was very depressed but didn’t want to take drugs. They chose therapy after leaving the hospital.13

For those facing Diogenes syndrome, joining support groups or getting help online can be good.11 Getting better is possible with the right support.11 Still, some people avoid help, which makes it hard for doctors and can lead to legal problems too.12 Many need help with cleaning and personal care to deal with this situation.12

Not much is known about how often Diogenes syndrome happens. It’s not in the main guide for diagnosing mental health issues.12 But, it seems to make life shorter for those who have it.12 One study talked about a 51-year-old man who was deeply affected.13 His home had a lot of garbage and was very dirty.13

Art-Induced Psychological Responses

In recent years, the field of psychological aesthetics has caught a lot of attention. It’s because millions of people worldwide often come across various works of art.14 One intriguing area within this field is the Stendhal syndrome. It’s also called hyperculturemia or Florence syndrome.14

Stendhal syndrome shows up when people see art they find stunning. Or when they are surrounded by lots of art in one place, like a museum.15 Symptoms might include feeling anxious, having panic attacks, feeling disconnected from reality, being confused, and even seeing things that aren’t there.15

The syndrome takes its name from the French author Stendhal. He felt these symptoms during a visit to Florence in 1817.15 What’s more, seeing nature’s beauty can also trigger these feelings. This shows how deeply art and nature can affect our minds and bodies.15

Interest in art and how it affects us emotionally has increased recently. This is because researchers are now using new methods to study the link between our brains, behavior, and feelings towards art.14 They’ve found several brain areas that light up when we enjoy art, like the orbitofrontal and prefrontal cortex.15

In addition, seeing something that we find beautiful activates key brain areas linked to our emotions. These include the areas responsible for our feelings of reward and decision-making.15 This shows that art and beauty don’t just stir our emotions – they affect our thoughts and even our body’s reactions.14

Stendhal Syndrome

Stendhal syndrome, or hyperculturemia, is a unique and captivating response to art and beauty.15 It leads to feelings of anxiety, panic attacks, and even seeing things that are not real. These reactions can happen when someone finds art exceptionally beautiful or when there’s a lot of art around them.15

This phenomenon gets its name from the French writer Stendhal. He first experienced these symptoms during his trip to Florence in 1817.15 It’s interesting to note that similar reactions can occur in response to nature’s beauty. This shows just how deeply our minds and bodies react to beauty.15

Studying Stendhal syndrome and similar responses to art has become a significant focus.14 Researchers are diving into the complex connection between art, our emotions, and the way our brains work.14 Understanding these mechanisms gives us a better sense of the impact art has on our happiness and well-being.14

Body Integrity Identity Disorders

Apotemnophilia, or body integrity identity disorder (BIID), is rare. It makes individuals want to remove healthy body parts.16 They may harm themselves to remove the body parts. This disorder is thought to come from the brain. People with this condition may try to cut off their own limbs. Or, they might hurt their limbs so that it’s necessary to cut them off.17


Those with apotemnophilia wish to remove one of their healthy limbs.16 This feeling often starts early and can result in self-harm. Or they might ask a doctor to remove their limb.17 Often, these individuals also have depression, mood problems, and feel unhappy long-term. Some think this condition is present from birth.16

Alien Hand Syndrome

Alien hand syndrome features the uncontrollable movement of the hands. The individual feels like the hand moves without their control, as if it’s not part of their body.16 It is linked to issues in the brain, especially the right parietal lobe, involved in movement and planning.17

These conditions show a deep link between how the brain sees the body and personal identity. While finding effective treatments is hard, focusing on research and raising awareness can help. It might improve how we support people with these uncommon mental health issues.1617

Delusional Misidentification Syndromes

Delusional misidentification syndromes (DMSs) are rare disorders with delusional beliefs. People with these syndromes see familiar faces as impostors or think multiple strangers are just one person.18 For example, Capgras syndrome makes someone think their loved ones are replaced by identical impostors. Fregoli delusion causes the belief that strangers are secretly someone the patient knows.19 Then there’s Cotard’s delusion, the “walking corpse” syndrome, making individuals believe they are dead or disappeared.18

Diagnosing and treating DMSs has been a challenge in the mental health field. Over the last 80 years, experts have struggled with these syndromes because they’re not easy to understand or treat.19 Research shows overlapping symptoms with conditions like schizophrenia, mood disorders, and physical illnesses such as typhoid fever.19 Scientists have found brain abnormalities related to DMSs. They’re often linked to lesions in the right frontoparietal regions of the brain.19

See also  Your Mental Health Journey: Embrace the Path to Wellness

Brain imaging like SPECT and brain activity tests have helped study DMS. They’ve focused on the right hemisphere’s frontal and parietal lobes. These body imaging techniques show promise in uncovering more about DMS.19 Capgras syndrome and Fregoli syndrome are the two main DMS types known.19

Cases with Capgras and Fregoli syndromes highlight the disorder’s challenges. People mistaken their loved ones or see different people as one show the complex nature of DMS. This creates difficulties for those trying to help.19 Detailed case studies show the complex lives of those with Capgras and Fregoli. They explain the difficulties and importance of treating these syndromes properly.19 These cases stress how crucial accurate diagnosis and treatment are for managing DMS.19

Perceptual Distortions

Alice in Wonderland syndrome (AIWS), or Todd syndrome, is a rare condition affecting how people see their own bodies, time, or space.20 It can cause hallucinations, distort senses, and make people feel things are speeding up or slowing down. The main sign is getting confused about the size and shape of body parts.20 AIWS links to frequent migraines, brain tumors, or drug use. It most often affects children aged five to 10.20 These changes in perception can make people panic or feel scared.

Alice in Wonderland Syndrome

Todd syndrome is named after John Todd, a neurologist, since he first described it in 1955. It’s all about seeing things differently, such as objects or body parts appearing too small or too big, which is called metamorphopsias.20 Time might seem to change, feeling like it’s speeding up or slowing down.20 These weird perceptions can really upset daily life and activities.

The cause of AIWS isn’t crystal clear, but it’s thought to be due to problems in how the brain processes visuals.20 It often shows up with migraines, brain tumors, or some meds, hinting at a physical or neurological root.20 Scientists are still studying to fully understand AIWS.

AIWS, though rare, changes people’s lives in big ways.20 It brings on strange sights and feelings, which can be both confusing and scary, leading to more anxiety and panic. But with the right help, like cognitive-behavioral therapy and managing medication, folks with AIWS can handle their symptoms better and live well.

Dissociative Identity Disorder

Dissociative identity disorder (DID), once named multiple personality disorder, is a mental health condition. The DSM-5 describes it as having two or more distinct identities. These identities, called alters, perceive the world differently and have their own histories and likes. Trauma in childhood is often the cause, leading to the creation of these alters. They help the person deal with the hurt from traumatic events. People with DID often struggle to handle stress and feel disconnected from their emotions and selves.821

About 1.5% of the world’s people have DID. It takes about 5 to 12.5 years on average for a diagnosis for someone with DID. A small percentage of the world, from 1% to 1.5%, experience severe forms of this disorder. Between 1% to 5% of people globally have some form of dissociative disorder. Those with DID tend to hurt themselves or try to commit suicide more often. They are also easier to hypnotize compared to those with other mental health issues.8

DID can affect about 1% of the world. Women are more commonly diagnosed than men. Almost everyone with these disorders has had severe and repeated traumas in their childhood. They spend about 7 years getting various mental health treatments before finally being diagnosed with DID. Usually, they start with 2 to 4 different personalities, which can grow to 13 to 15 as they go through therapy. Actors like Marilyn Monroe and people like Herschel Walker have gone public about living with DID.21

The chances of finding DID are higher in psychiatric hospitals. Here, about 5% of patients might have it. Among outpatients, the chances are between 2 to 3%. In the general population, around 1% is affected. Over 70% of those with DID have tried to kill themselves, and 90% say they were abused in childhood. Main treatment is therapy, lasting at least six months, with a mix of talking and medicine to help with stress and anxiety.22

Substances like marijuana and cocaine can make DID symptoms worse. DID usually starts with a “host” identity that feels helpless and sad. Other identities are more active and have their own feelings and memories. These different personalities cause memory gaps and problems that can’t be blamed on drugs or physical health issues. Stress and drug use can set off these symptoms, but it’s not clear if both are always needed. Many times, after a personality shift, the patient feels bad and confused. Others often report these feelings more than the patients themselves.22

Obsessive-Compulsive Personality Disorder

Obsessive-compulsive personality disorder (OCPD) is about always wanting things perfect, neat, and under control. People with OCPD focus so much on work that they ignore friends. They also do things over and over again, which stops them from having a normal day.23 Feeling the need to make everything just right can really upset them.

This is different from obsessive-compulsive disorder (OCD). In OCPD, the people often don’t realize how their strict actions affect others.

About24 7.9% of people in the United States have OCPD.24 6.6% of adults with OCD also have it. And24 21% of those with OCD share the same perfectionist traits.

OCPD can be more common in some groups. For example,24 41.2% of Hispanic patients who see psychiatrists might show signs of OCPD.

Knowing if someone will keep these traits for two years can help with treatment plans. About half of the people diagnosed will still have OCPD.24 OCPD also makes it harder for therapy to work well, with a 44.4% less benefit. And it predicts not doing well with medicine either, with a 45% chance.

Dealing with obsessive-compulsive personality disorder is tough. It significantly changes how a person lives and relates to others.23 Signs usually show up when a person is a teenager or in their early 20s. It’s more likely to happen as someone gets older, affecting 3 to 8% of people.23 OCPD often comes with other mental health issues like eating disorders or mood problems, as well as other personality issues.23 People might not want help because they’re very stubborn and really about doing things perfectly.

Prevalence of obsessive-compulsive personality disorder (OCPD) in Hispanic psychiatric outpatients41.2%24
Prevalence of DSM-IV OCPD in the United States7.9%24
Prevalence of obsessive-compulsive personality disorder in adults with obsessive-compulsive disorder6.6%24
Prevalence of DSM-III-R personality disorders in adolescents14.3%24
Two-year stability rate of obsessive-compulsive personality disorder50%24
Prevalence rate of comorbid obsessive-compulsive personality disorder in patients with obsessive-compulsive disorder (OCD)21%24
Impact of obsessive-compulsive personality disorder on cognitive behavior therapy for obsessive-compulsive disorder44.4%24
Predictive value of obsessive-compulsive personality disorder in anti-obsessional pharmacological treatment45%24
OCPD affects between 3 to 8 percent of the population3-8%23
OCPD is most common in older individuals23
OCPD typically starts to manifest during a person’s teenage years or early adulthood23
People with OCPD must exhibit at least four out of the eight identified signs to receive a diagnosis23
Between 15 to 28 percent of people with OCD may also have OCPD15-28%23
OCPD individuals may be less willing to accept treatment due to their stubborn nature23
See also  Mental Health Solutions: Effective Strategies and Resources

Histrionic Personality Disorder

Histrionic personality disorder is all about being the center of attention. People with HPD see themselves differently than others do.25 They feel good when other people like them. This leads to them doing things like being too flirty, thinking only about themselves, and not being honest with people. All this makes their relationships not so great.25 HPD can make it hard for them to get along well with others. But it doesn’t usually stop them from doing okay in life.25

Histrionic Personality Disorder (HPD) often appears when someone is around 18 to 20 years old.25 People with HPD are often described as really into themselves, liking to show off, enjoying lots of drama, and being very loud and lively.25 Doctors and psychologists have seen HPD as a real problem since the middle of the 20th century.25 More recently, the DSM-5-TR, a big book about mental health, has agreed that HPD is its own thing.25

Mental health experts group personality disorders in three ways in the DSM-5-TR. There’s Cluster A, which is odd or eccentric, Cluster B, which is all about being dramatic or emotional, and Cluster B, which is anxious and fearful.25 They think both genetics and the things that happen around us help cause HPD.25 Research with twins has shown that family and life experiences can play a big role in having HPD.25

Having histrionic personality disorder (HPD) is pretty rare, happening in about 1 out of every 100 people. This makes it a rare mental condition compared to other personality issues.26 For example, narcissistic personality disorder (NPD) is seen in up to 5 people out of 100.26 More men get diagnosed with NPD, while more women get diagnosed with HPD. This shows a clear difference by gender.26

People with histrionic personality disorder might show their feelings very dramatically, which is not very common in people with NPD.26 They are more likely to have certain problems like thinking they are sick when they are not.26 Also, they might talk about hurting themselves to get others to pay attention to them.26

The reasons why someone with HPD or NPD wants attention are different. Those with NPD feel like they are better than everyone and should be noticed. Yet, those with HPD just want to feel they are okay because they doubt themselves.26 Growing up in a rough or neglectful home is thought to make HPD more likely, besides the influence of genes and social situations.26

Histrionic personality disorder and narcissistic personality disorder can both be helped by talking to a doctor and perhaps taking medicine.26 But, people with HPD or NPD might not see their actions as wrong. So, sometimes family and friends need to be the ones to start getting them help.26 Over time, talking with a therapist can really make a difference for someone with NPD or HPD. It helps them understand why they feel and act the way they do.26


Rare mental disorders can greatly affect those who have them. They often come with strange and unique symptoms. Sometimes, even doctors find them hard to recognize or treat.27 It’s key to know about the rare mental disorders‘ causes and signs. This knowledge helps more people get the right help.28

While we still have lots to learn about these disorders, there are ways to help. Using special medicines and talking to a therapist can make a big difference. It helps patients have better lives.27 Keeping up with research and spreading the word about rare mental health issues matters. This work helps make sure communities offer strong mental health support.28


What are some of the rarest mental disorders?

Some very rare mental disorders are Capgras syndrome and Cotard’s delusion. There’s also Fregoli delusion and clinical lycanthropy.Other examples are Diogenes syndrome, Stendhal syndrome, apotemnophilia, and Alice in Wonderland syndrome.

What are the symptoms of rare mental disorders?

Rare mental disorders show in unusual and strange ways. People might have delusions or see things that aren’t real.They could also hoard things compulsively or experience drastic changes in how they view things.Even experts find these symptoms hard to deal with.

How common are rare mental disorders?

Common mental disorders like depression affect a lot of people. On the other hand, rare mental disorders don’t.They are not seen often but knowing about them helps to treat them when they do appear.

What are some examples of cultural syndromes?

Cultural syndromes are mental issues that some specific cultures face. One is Khyâl cap, or “wind attacks,” seen in Cambodians.The Shona people in Zimbabwe have Kufungisisa, also known as “thinking too much.” These syndromes are unique to their cultural context.

What are delusional misidentification syndromes?

Delusional misidentification syndromes cause people to have false beliefs about what’s real. For instance, Capgras syndrome makes someone think loved ones have been replaced by imposters.Others include Fregoli delusion, where a person believes everyone looks and acts the same, and Cotard’s delusion, which makes someone think they are dead or don’t exist.

What is dissociative identity disorder?

Dissociative identity disorder, once called multiple personality disorder, means having different identities. These identities see the world and the self in their own way.This disorder is often connected to experiencing severe trauma in childhood.

How are rare mental disorders treated?

Treating rare mental disorders requires a mix of meds and therapy. This combo can help patients with these conditions live better lives.Improving how we understand and address these disorders is key for better mental health outcomes.

Source Links

  1. https://theprivatetherapyclinic.co.uk/blog/10-of-the-rarest-mental-health-disorders/
  2. https://kentuckycounselingcenter.com/rare-mental-disorders/
  3. https://en.wikipedia.org/wiki/Culture-bound_syndrome
  4. https://thinkculturalhealth.hhs.gov/assets/pdfs/CulturalSyndromes.pdf
  5. https://my.clevelandclinic.org/health/diseases/9599-delusional-disorder
  6. https://www.webmd.com/schizophrenia/delusional-disorder
  7. https://my.clevelandclinic.org/health/diseases/17749-dissociative-disorders
  8. https://www.ncbi.nlm.nih.gov/books/NBK568768/
  9. https://online.csp.edu/resources/article/10-rare-mental-health-conditions/
  10. https://www.brainsway.com/knowledge-center/rare-mental-health-disorders/
  11. https://www.healthline.com/health/diogenes-syndrome
  12. https://www.medicalnewstoday.com/articles/314595
  13. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8639269/
  14. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4844603/
  15. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6349741/
  16. https://www.webmd.com/mental-health/what-is-body-integrity-identity-disorder
  17. https://pubmed.ncbi.nlm.nih.gov/19132621/
  18. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9045998/
  19. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2963468/
  20. https://www.mentalhelp.net/personality-disorders/defining-features-distorted-thinking-patterns/
  21. https://www.webmd.com/mental-health/dissociative-identity-disorder-multiple-personality-disorder
  22. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6132594/
  23. https://www.helpguide.org/articles/mental-disorders/obsessive-compulsive-personality-disorder-ocpd.htm
  24. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6343421/
  25. https://www.ncbi.nlm.nih.gov/books/NBK542325/
  26. https://www.charliehealth.com/post/whats-the-difference-between-narcissistic-and-histrionic-personality-disorders
  27. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5428165/
  28. https://www.ncbi.nlm.nih.gov/books/NBK20369/