ADHD Comorbidities & Related Conditions

What Is a Personality Disorder? Symptoms of Borderline, Histrionic, Narcissistic & Other PDs

Personality disorders are mental health conditions like borderline, histrionic, narcissistic, or antisocial personality disorder that cause unhealthy patterns of thought and behavior. Though they occur in one out of every ten adults, personality disorders remain largely misunderstood. Here, we review the symptoms, types, causes, and treatments of Cluster A, B, and C PDs.

By Tori Morales Verified Medically reviewed by Roberto Olivardia, Ph.D. Updated on April 28, 2023
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Depression, fatigue, mental stress, pain, frustration, overwhelmed, too much, concept. Young depression frustrated stressful woman or girl cartoon character holding head. Fatigue psychological problems or headache bad news.

What Is a Personality Disorder?

Personality disorders are mental health conditions like borderline, histrionic, narcissistic, or antisocial personality disorder that cause unhealthy patterns of thought and behavior that persist over time and across situations, causing significant distress or impairment1. Though each personality disorder has unique features, common symptoms include:

  • Atypical emotional expression
  • Difficulty maintaining relationships
  • Unorthodox thought patterns

Personality disorders are serious mental health conditions that affect almost 10% of American adults and are frequently comorbid with mood disorders, anxiety disorders, and substance use disorders2. Up to 73% of people with substance use disorders met the criteria for at least one personality disorder, according to a study published in European Psychiatry3. Still, the mental health condition is largely misunderstood and plagued by persistent stereotypes

Though notoriously difficult to treat, personality disorders may respond positively to psychotherapy and well-targeted medication. Some personality disorders also decrease in severity with age, though this is not universally true.

Here, learn about the most common personality disorders, and their symptoms, causes, treatments, and links to attention deficit hyperactivity disorder (ADHD). Consult with a mental health professional if you recognize these symptoms in yourself or your child.

[Self-Test: Symptoms of Borderline Personality Disorder]

What Causes Personality Disorders?

Like many mental health conditions, there is no universal cause of personality disorders; every case is different. However, recent research has identified several key factors that may contribute to the development of personality disorders:

  • Genetics. Some genes are linked to personality disorders, especially antisocial personality disorder. One current theory suggests that genetic factors may “prime” an individual to develop a personality disorder when faced with specific circumstances.4
  • Abuse. Especially in childhood, abuse may significantly increase an individual’s chance of developing a personality disorder. Potential triggers include sexual abuse, verbal abuse, and emotional neglect, according to research.5
  • High reactivity. Some research suggests that highly sensitive infants — those unusually sensitive to light, sound, and other stimuli — may be at higher risk for developing personality disorders6.
  • Peers and mentors. Having supportive peers or mentor figures in childhood may protect against personality disorders. Those who lack peer or mentor support may be more likely to develop a personality disorder.7

What Are the 10 Personality Disorders?

The ten personality disorders recognized in the Diagnostic and Statistical Manual of Mental Disorders (DSM-5) are split into clusters A, B, and C, based on their symptoms.

Cluster A

Cluster A personality disorders cause individuals to appear odd or eccentric. They include:

  • Paranoid personality disorder (PPD) causes people to act unusually suspicious of others. People with PPD doubt the trustworthiness of friends and romantic partners, often accusing them of infidelity and incorrectly perceiving innocuous statements as personal attacks.
  • Schizoid personality disorder (ScPD) is characterized by a lack of desire to have close platonic, romantic, or sexual relationships. Other symptoms may include a desire for isolation, restricted emotional expression, and a lessened ability to take pleasure from activities. Someone with ScPD may seem disinterested in pursuing life goals.
  • Schizotypal personality disorder (STPD) causes atypical speech, limited emotional inflections, eccentric appearance and behavior, magical thinking, and discomfort with close relationships. Individuals with STPD often interpret events as being disproportionately emotionally important and hold superstitious beliefs.

[Download: 9 Conditions Often Linked to ADHD]

Cluster B

Cluster B personality disorders cause individuals to appear erratic, emotional, or dramatic. They include:

  • Antisocial personality disorder (ASPD) is a pattern of unlawful, aggressive, deceitful, reckless, impulsive, irresponsible, and remorseless behavior. People diagnosed with ASPD must demonstrate symptoms of conduct disorder, such as a lack of regard for basic social norms before age 15 and may lack empathy. ASPD, unlike other personality disorders, cannot be diagnosed in individuals younger than 18.
  • Borderline personality disorder (BPD) is characterized by instability in self-image, relationships, and emotions, plus impulsive and self-harming behaviors. People with BPD may also experience excessive anger and, under certain circumstances, display psychotic-like behaviors such as hallucinations and delusions.
  • Histrionic personality disorder (HPD) causes rapidly shifting emotions, attention-seeking behavior, inappropriate sexually seductive behavior, self-dramatization, and discomfort when the individual is not the center of attention. People with HPD may also engage in manipulation of and dependence on romantic partners.
  • Narcissistic personality disorder (NPD) is a pattern of grandiosity, fixation on power fantasies, desire for admiration, arrogance, lack of empathy, and envy. NPD may also cause individuals to be overly sensitive to criticism, though they may not externalize those feelings.

Cluster C

Cluster C personality disorders cause individuals to appear fearful or anxious. They include:

  • Avoidant personality disorder (AvPD) causes feelings of inadequacy, fear of rejection, and sensitivity to negative feedback. People with AvPD may avoid potentially embarrassing social situations, as they view themselves as socially incompetent. AvPD may resemble social anxiety disorder.
  • Dependent personality disorder (DPD) is characterized by a need for nurture, clinginess, indecisiveness, low self-confidence, passiveness, and a perpetual desire to be in a relationship with a caretaking figure. People with DPD often belittle themselves and believe they are incapable of caring for themselves.
  • Obsessive-compulsive personality disorder (OCPD) causes an excessive focus on order and organization, strict perfectionism, inflexibility on moral or ethical matters, and hoarding tendencies. People with OCPD are very rigid and struggle to work with others.

[Read Next: When It’s Not Just ADHD – Symptoms of Comorbid Conditions]

How Are Personality Disorders Diagnosed?

Personality disorders, like other mental health conditions, can be diagnosed by a physician, psychologist, psychiatrist, or psychiatric nurse practitioner. The practitioner will evaluate symptoms by interviewing the individual and loved one, and by using questionnaires, if available.

A comprehensive personality disorder assessment will also rule out differential diagnoses by screening for comorbid conditions. For example, a clinician evaluating an individual for Cluster C disorders should ensure that an anxiety disorder does not better explain symptoms. Up to 67% of people with personality disorders have another mental health disorder8. It is also possible for someone to have more than one personality disorder9.

Though the DSM-5 does allow diagnosis of personality disorders in children, this is relatively rare as it is difficult to differentiate personality disorders from developmentally appropriate behaviors. Personality disorder diagnoses are most often made in adolescence and adulthood, with the exception of ASPD, which can only be diagnosed in adulthood10.

Personality disorders are likely underdiagnosed because many people with personality disorders do not recognize their negative behaviors and thought patterns, and therefore do not seek treatment11.

How Are Personality Disorders Treated?

Personality disorders are commonly treated with psychotherapy. Dialectical behavior therapy (DBT), a type of cognitive behavioral therapy (CBT), was initially developed in the 1980s by Seattle psychologist Marsha Linehan, Ph.D., specifically to treat BPD.

A study published in Borderline Personality Disorder and Emotional Dysregulation found that three-quarters of patients no longer met the symptom criteria for BPD after undergoing DBT treatment12. Cognitive behavioral therapy (CBT), psychodynamic therapy, and relational therapy are also used to treat personality disorders.

While there is no approved medication specifically for personality disorders, targeted medication can treat symptoms such as depression, anxiety, mood instability, and delusions.

What Is the Link Between Personality Disorders and ADHD?

Research on ADHD and comorbid personality disorders is scarce. One small study of adults with ADHD found that personality disorders, especially Cluster B and Cluster C disorders, were present in over half of subjects.13 More research is warranted on the co-occurrence of ADHD and personality disorders. As both conditions are widely misunderstood and underdiagnosed, there is much room for misdiagnosis. Often, people with ADHD may be diagnosed with a personality disorder if a clinician is not well-versed on ADHD. Similarly, if an ADHD specialist is not fully educated on personality disorders, they may think symptoms are part of ADHD when they may be better explained by a personality disorder.

Indeed, ADHD shares traits with some personality disorders, especially Cluster B disorders. Impulsivity, emotional volatility, and relationship difficulty are common symptoms of both conditions, which can lead to misdiagnosis. Attention difficulties, hyperfocus, and hyperactivity are unique to ADHD and can help differentiate it from personality disorders.

What Is Personality Disorder? Next Steps

The Clinicians’ Guide to Differential Diagnosis of ADHD from Medscape and ADDitude

View Article Sources

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6Charlotte Huff, Where Personality Goes Awry, Monitor Staff, March 2004, Vol 35, No. 3, https://www.apa.org/monitor/mar04/awry
7Oldham, J. M., Skodol, A. E., & Bender, D. S. (Eds.). (2005). The American Psychiatric Publishing textbook of personality disorders. American Psychiatric Publishing, Inc. 217
8Lenzenweger, M. F., Lane, M. C., Loranger, A. W., & Kessler, R. C. (2007). DSM-IV personality disorders in the National Comorbidity Survey Replication. Biological psychiatry, 62(6), 553–564. https://doi.org/10.1016/j.biopsych.2006.09.019
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12Stiglmayr, C., Stecher-Mohr, J., Wagner, T. et al. Effectiveness of dialectic behavioral therapy in routine outpatient care: the Berlin Borderline Study. Borderline Personality Disorder and Emotional Dysregulation, 1, 20 (2014). https://doi.org/10.1186/2051-6673-1-20
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