Rare Mental Disorders: What You Need to Know

*Approximately 1 in 5 Americans struggle with a diagnosable mental disorder. There’s no doubt that these disorders can be challenging. They can impact one’s entire well-being and disrupt interpersonal relationships, finances, and careers.

That said, rare mental disorders can be even harder to understand. Many people don’t recognize what’s going on. Their loved ones may not know how to provide support. At times, even treatment providers may misinterpret or misdiagnose symptoms.

However, mental disorders are treatable. Recovery is possible. Let’s review some of these rare conditions.

Brief Psychotic Disorder

Brief psychotic disorder can emerge after a stressful event. The symptoms of this disorder include:

  • Strange, bizarre behavior that doesn’t fit normal functioning.
  • False beliefs or thoughts about self or others (delusions).
  • Hearing, seeing, touching, or smelling things that aren’t real (hallucinations).
  • Speaking strangely in an illogical manner.

These symptoms must occur outside of drug or alcohol use. A brief psychotic episode lasts longer than a day, but it ends before one month. Psychiatric evaluations can confirm the disorder.

Sometimes, this condition represents the starting point for mental disorders like schizophrenia, bipolar disorder, or schizoaffective disorder.

Although the symptoms can feel scary, the prognosis tends to be good if someone seeks early intervention. Treatment typically consists of a combination of antipsychotic drugs and therapy. 


Catatonia refers to a cluster of symptoms that involve a lack of communication and movement. It can also include confusion, irritability, and restless behavior. Doctors originally categorized catatonic behavior as schizophrenia. However, medical professionals now understand that catatonia can accompany a variety of other mental disorders. The common symptoms include:

  • Lack of communication.
  • Failing to respond or speak to other people.
  • Maintaining a strange, unusual body position.
  • Resisting others if they try to move the body.
  • Agitation and irritability.
  • Repetitive body movements. 
  • Mimicking someone else’s speech or behaviors. 

There are different types of catatonia. Akinetic catatonia refers to the “blank stare” phenomenon. It appears like you’re talking to someone, but they can’t register what you’re saying. Excited catatonia refers to heightened movements that seem random, impulsive, or pointless. They may also present as agitated or combative. Finally, malignant catatonia happens when the symptoms result in health issues like blood pressure changes or slowed breathing.

Catatonia usually requires pharmacological treatment. Sedatives like benzodiazepines can help. Additionally, in severe cases, some people benefit from electroconvulsive therapy (ECT).

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Depersonalization/Derealization Disorder (DDD)

DDD is a rare mental disorder that results in people feeling outside of their body. It also can include feeling like things outside of them aren’t real. Common symptoms include:

  • Feeling completely numb to sensations or emotions.
  • Feeling disconnected to the mind and body.
  • Experiencing detachment from past memories or experiences.
  • Believing that your body and limbs are distorted.
  • Feeling extreme awareness of your surroundings.
  • Perceiving recent events as events that happened a long time ago.
  • Seeing surroundings through a distorted lens (i.e, two-dimensional, larger-than-life, colorless).

Unlike with psychotic disorders, people struggling with DDD have insight into their experiences. Many of them fear that something is wrong with them. Only around 2% of people who have experienced a dissociative episode meet the criteria for DDD.

Many risk factors can trigger DDD. It’s largely associated with trauma, both in childhood and adulthood. It can also come from persistent stress and grief. Additionally, drug use can trigger symptoms.

Treatment can help reduce and even eliminate some symptoms. The likelihood of recovery is maximized when people work through their underlying stressors. Cognitive-behavioral therapy (CBT) can help with obsessive thinking. It can also help with grounding techniques, which can root people back into reality. Eye movement desensitization and reprocessing (EMDR) can also help with traumatic memories and mindfulness.

Dissociative Identity Disorder (DID)

Once coined as multiple personality disorder, DID consists of:

  • Two or more separate sets of identities (known as personality states). Each personality has its own unique memories, behaviors, thinking patterns, and preferences.
  • Persistent gaps in memory related to daily events, personal details, and previous traumas.
  • Ongoing symptoms that cause significant distress in routine functioning.

Although it’s frequently depicted in the media, actual clinical cases of DID are extremely rare. Almost everyone with DID has a history of trauma, severe childhood neglect, or recurrent abuse.

Watch Encina Severa discuss her experience with DID and meet one of her alters, Minnie – a three year-old girl.

It’s no surprise that this condition can be debilitating for individuals and their loved ones. That’s because it may be challenging to convince someone about what’s going on. The sufferer may remain in one identity state for several months or even years before shifting into another one.

Treatment usually consists of psychotherapy. Therapy helps people to learn more about their symptoms. It can also support the identification and integration of different identity sets. 

Medication can also help. Many people struggling with DID also struggle with disorders like depression, anxiety, or bipolar disorder. Antidepressant or antipsychotic medications can help alleviate some of those symptoms. As a result, the individual may be less likely to shift into another identity.

Factitious Disorder

Factitious disorder refers to someone lying to others by appearing to be sick. It can also occur when a caregiver falsely presents a child as being ill or injured (previously known as Munchausen syndrome by proxy). 

Factitious disorder varies in severity. On the mild end of the spectrum, people may slightly exaggerate their symptoms. On the extreme end, they may engage in serious self-mutilation, tamper with medical tests, or shop around and meet with dozens of doctors to obtain a diagnosis. Common symptoms include:

  • Having overly extensive knowledge about certain medical diseases.
  • Being eager and seemingly excited about risky operations or procedures.
  • Experiencing vague symptoms that get worse without a specific reason.
  • Having symptoms that don’t respond to appropriate medical treatments.
  • Visiting many different doctors or hospitals.
  • Making up symptoms or making up family medical histories.
  • Causing direct self-harm.
  • Tampering with medical devices or tests.
  • Refusing to allow the doctor to speak to other family members.

Factitious disorder often results from trauma. It can also coincide with serious medical illnesses in childhood, feeling of abandonment, and a weak sense of self-identity. 

Early treatment is imperative. Factitious disorder can be life-threatening. If a child is involved, it can be even more detrimental. Therapy can help sufferers understand other ways to cope with distress. It can also provide a safe, nonjudgmental environment for processing the underlying motives associated with the condition.

Histrionic Personality Disorder

Histrionic personality disorder refers to intense emotions and unstable self-esteem. People with this condition experience an immense desire to be recognized. They depend on other people for approval, validation, and inherent self-worth. However, they often act irrationally or dramatically to gain this attention.

histrionic personality disorder

Women are more likely to have this condition than men. Common symptoms include:

  • Impulsive behavior.
  • Exhibiting clear discomfort when not the center of attention.
  • Often appearing to be performing before an audience.
  • A constant need to seek approval and reassurance from others.
  • Extreme focus on physical appearance.
  • Rapid and intense emotions.
  • Having a limited threshold for routine, frustration, or perceived boredom.
  • Provocative dressing and seductive, sexual behavior. 
  • Self-centeredness.
  • Making comments about suicide or attempting suicide.

Many people with this condition struggle in their relationships. They may also struggle at work, school, or in other areas of functioning. It’s not uncommon for them to have unstable relationships full of intense emotions.

Histrionic personality disorder can run in families. It can also occur when a child is abused or neglected. Sometimes, children receive approval for certain behaviors, and they continue engaging in those behaviors for ongoing reinforcement.

Many people don’t seek intentional treatment for their histrionic personality disorder. Instead, they might start therapy for relationship problems, depression, or substance use. However, therapy can help with histrionic symptoms. Therapists can teach new ways of coping with stress and also work to help strengthen ego and self-identity.

Obsessive-Compulsive Personality Disorder  (OCPD)

Many people have heard about obsessive-compulsive disorder (OCD). However, OCPD is different than the common anxiety disorder. OCPD entails:

  • Extreme rigidity with rules and regulations.
  • An intense need to have order and control.
  • The sense of self-righteousness about how things must be done.
  • Discomfort or unwillingness associated with delegating tasks to others.
  • Extreme perfectionism that can interfere with finishing tasks.
  • Lack of generosity and extreme frugality.

People with OCPD often believe their way is best, and they struggle to accept other perspectives. If they can’t get their way, they often feel out-of-control, anxious, and even resentful.  About 1% of the US population has OCPD, and men are twice as likely to have it than women.

OCPD can stem from trauma. It can also come from rigid expectations during childhood. The desire to control can come from unmet needs of control. Likewise, the perfectionism can result from an extreme fear of failure. 

Cognitive-behavioral therapy (CBT) can help people with OCPD. CBT teaches people how to change their thinking patterns and adopt more realistic points of view. It also can help with mindfulness, relaxation, and acceptance. Additionally, some people with OCPD benefit from antidepressant medication. Medication can help with symptoms of depression and anxiety, which can exacerbate one’s rigidity.


Pica is an eating disorder that entails eating items that are not considered traditionally edible. Common pica examples include dirt, paint chips, clay, cigarette ashes, and glue. 

The disorder is more common in children. However, it can also occur in adults. Pregnant women with iron or zinc deficiencies sometimes report pica-related cravings.

Pica can result in numerous physical issues, including:

  • Gastrointestinal problems.
  • Bloody stools.
  • Lead poisoning.
  • Intestinal blockages and tears.
  • Infections.

Many children with pica outgrow it naturally. However, some people need professional treatment. Pica treatment entails examining the underlying issues impacting these cravings or compulsions. It may include replacing certain habits/foods with more appropriate and safe choices.

Reactive Attachment Disorder

Reactive attachment disorder is a rare childhood disorder where the infant or child fails to securely attach to their caregiver. This can happen due to neglect, severe trauma, inconsistent parenting, or early life disruptions. The main symptoms include:

  • Sad and disengaged presentation.
  • Avoiding comfort or displaying apathy if comfort is given.
  • Limited or no smiles.
  • Watching others intensely without engaging in the interactions.
  • Refusing to ask for assistance.
  • Avoiding holding their hands out for being picked up.
  • Disinterest in interactive games with the caregiver.

All children need a stable and supportive environment to thrive. It’s essential caregivers attune to their child’s basic needs. Frequent ignoring or misinterpreting cues can result in attachment problems

In adulthood, reactive attachment disorder can result in behavior problems, abusing other people or animals, severe relationship issues, and substance use.

Treatment usually consists of family therapy or parenting classes. These treatments can help parents with engagement, nurturing, and empathy. At times, the child may also benefit from individual therapy. 

Selective Mutism

Selective mutism is a complex childhood anxiety disorder. Although the child may speak freely at home, they cannot or do not speak in various social situations. This disturbance can compromise their academic achievements or social relationships.

Selective mutism stems from anxiety. Many children with this condition also have social phobia. They feel extreme nervousness and worry about others. Instead of speaking directly, they tend to rely on nonverbal body language (nods, smiles, pointing, and even whispering) to communicate. Usually, they feel panicked about being ignored or criticized if they do speak.

Selective mutism can stem from:

  • Co-occurring anxiety disorders.
  • Trauma.
  • Family dynamics with hindered social contact.
  • Shy or timid temperaments.

Treatment involves reducing the child’s anxiety. It may also include reinforcement for positive communication patterns. Usually, the child must practice exposure-based therapy. In this therapy, the child practices saying words in a safe and gradual way. This strategy eventually desensitizes the extreme anxiety. 

Watch MedCircle original series about mental health and children.

Final Thoughts On Rare Mental Disorders

All mental disorders are serious. They all can impact someone’s emotional and physical well-being.

With that in mind, rare mental disorders often require additional care and attention. It’s imperative that people get the support they need. Recovery is obtainable, but the first step is reaching out for help. 


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Disclaimer: This information is not specific medical advice and does not replace information you receive from your healthcare provider. This is only a brief summary of general information. It does NOT include all information about conditions, illnesses, injuries, tests, procedures, treatments, therapies, discharge instructions or lifestyle choices that may apply to you. You must talk with your health care provider for complete information about your health and treatment options. This information should not be used to decide whether or not to accept your health care provider’s advice, instructions or recommendations. Only your health care provider has the knowledge and training to provide advice that is right for you.

You must talk with your health care provider for complete information about your health and treatment options. This information should not be used to decide whether or not to accept your health care provider’s advice, instructions or recommendations. Only your health care provider has the knowledge and training to provide advice that is right for you.

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