Mixed personality disorder (MPD) is the occurrence of traits of more than one personality disorder. Symptoms and treatment vary depending on the traits a person experiences.

Personality disorders affect mood, behavior, and cognition. They are chronic and interfere with a person’s functioning across social, occupational, and interpersonal areas.

If you know someone with a personality disorder, their behavior sometimes may not make sense. They may overreact, seem excessively dramatic, or be difficult to get along with.

They don’t mean to cause problems. Their behaviors are often due to a combination of genetics and environmental factors that change how their brains work.

MPD refers to when a person has traits of more than one personality disorder. They might have traits of several personality disorders but not enough to meet the diagnostic criteria for any. The formal name for this is “other specified personality disorder.”

Or MPD can refer to a diagnosis of one personality disorder with additional traits from other PDs.

Doctors diagnose personality disorders by evaluating a person’s long-term symptoms and functioning. They also speak with the person’s family members or close friends or associates, to get more information.

Diagnosis applies to adults only, since a person younger than 18 years of age is still developing their personality.

According to the American Psychiatric Association (APA), about 9% of US adults live with at least one of the ten personality disorders.

Personality disorders are grouped into three clusters, based on shared characteristics.

Cluster A

Cluster A personality disorders share eccentricity and suspicion as common traits. People living with a cluster A personality disorder often seem odd and reclusive.

  • Paranoid: People with paranoid personality disorder are highly suspicious of others.
  • Schizotypal: This personality disorder has traits that resemble schizophrenia, including unusual behavior, magical thinking, and visual hallucinations.
  • Schizoid: People with this personality disorder are reclusive and have difficulties forming relationships.

Cluster B

Cluster B personality disorders cause a person to behave in an excessively dramatic way. They can be volatile, with exaggerated mood swings.

  • Borderline: A fear of abandonment is a factor that drives people with this personality disorder to anger, self-harm, and mood instability.
  • Antisocial: People with antisocial personality disorder may act impulsively, ignore societal norms, and exhibit a strong temper.
  • Narcissistic: Driven by a low sense of self-worth, people with narcissistic personality disorder demonstrate entitlement, sensitivity to criticism, and reduced or absent empathy.
  • Histrionic: This personality disorder causes a person to seek attention, obsess over physical appearance, and have trouble with serious relationships.

Cluster C

Cluster C personality disorders feature anxiety and abnormal fears.

  • Dependant: People with this personality disorder rely on others for emotional validation.
  • Avoidant: People with avoidant personality disorder experience low self-esteem and sensitivity to criticism which causes them to avoid social interactions.
  • Obsessive-compulsive: This personality disorder leads to perfectionism, inflexibility, and excessive conscientiousness.

Each personality disorder affects at least two of the following characteristics:

  • emotional responses
  • behavioral control
  • thoughts about self or others
  • interpersonal relationships

There’s a wide range of symptoms a person can exhibit if they live with MPD. It all depends on which personality disorders are involved.

For example, if they have received a diagnosis of narcissistic personality disorder (NPD) and also experience traits of borderline personality disorder (BPD) they will exhibit behaviors of both.

Narcissistic personality disorder:

  • exaggeration of achievements
  • fantasies about success and power
  • self-identification as being special
  • need for admiration
  • sense of entitlement
  • exploitative behavior toward other people
  • lack of empathy
  • envy
  • arrogance

Borderline personality disorder:

  • unstable relationships
  • impulsive behaviors
  • distorted self-image
  • self-harm, such as cutting
  • mood swings
  • inappropriate anger
  • feelings of disassociation
  • feelings of emptiness
  • fear of abandonment

Since there are ten personality disorders, MPD symptoms can be quite varied.

A 2020 study compared MPD, anxiety disorder, and a control group without either condition. The study found that the participants with MPD had a reduced ability to recognize:

  • fearful and angry facial expressions in a neutral context
  • neutral facial expressions in a happy context

The study also found deficits in:

  • interference resolution (inhibition of responses to irrelevant stimuli)
  • perspective taking
  • emotional regulation

Participants with MPD also exhibited increased distress when empathizing.

Multiple factors combine to increase your chance of developing a personality disorder.

They include:

  • genetics
  • social environment
  • adverse events in childhood
  • learned behaviors

Varying brain differences also have an influence.

For example, research has shown that NPD is associated with both gray and white matter abnormalities in certain brain regions.

Obsessive-compulsive personality disorder is linked to differences in brain areas related to habit formation, decision-making, and emotional modulation.

Oxytocin and serotonin dysregulation may contribute to borderline personality disorder.

The treatment for personality disorders is therapy.

Therapy helps a person understand their symptoms, and how to reduce the impact they have on themselves and others.

The type of therapy doctors recommend can depend on which PDs are present.

Some therapy options include:

Occasionally, doctors may prescribe medication for personality disorders to reduce the impact of certain symptoms.

An example is medication like lithium or valproic acid to reduce aggression, a trait found in antisocial personality disorder.

Personality disorders can be hard to treat, particularly when the person’s traits influence them to see treatment as unnecessary or suspicious. For example, if you live with paranoid personality disorder, it might be hard for you to trust a therapist.

However, with treatment, recovery is possible. The rates of recovery and time required for mixed personality disorder can vary depending on the traits a person experiences. People living with borderline personality disorder, for example, experience recovery at a rate of 33-99%.

If you or someone you know is experiencing MPD traits, an evaluation by a mental health professional can lead to a diagnosis and helpful treatment.

The first step is visiting your family doctor, who can give you referral information for a mental health professional.

Or you can try the following resources: