| disease | Personality Disorder |
| alias | Psychopathic Personality, Personality Abnormality, Pathological Personality |
The term "personality" has many different usages and lacks a unified definition. In psychiatry, it generally refers to a person's relatively stable and enduring patterns of mental activity or behavior, often used interchangeably with terms like temperament or character. Personality disorders were previously referred to as psychopathic personality or personality abnormalities, where certain traits of an individual's personality are excessively pronounced, disrupting their own or others' harmonious lives, thus drawing attention or being deemed necessary to address. The individuals themselves usually fail to recognize or refuse to admit these flaws. Personality disorders are generally not classified as diseases because they lack clear "onset," "fluctuations in condition," or medical treatment methods. However, since some individuals with originally normal personalities may develop symptoms of personality disorders due to psychiatric or organic brain diseases, or because some manifestations of personality disorders closely resemble psychiatric conditions, personality disorders have become a subject of study within psychiatry.
bubble_chart Etiology
The formation of personality traits was traditionally believed to be primarily determined by environmental factors ("one takes on the color of one's company"). Modern research, however, suggests that personality is the product of an interaction between heredity and environment, generally solidifying during adolescence and becoming difficult to alter thereafter. Studies have found that infants are born with certain temperamental traits (they are not "blank slates"), which immediately begin to interact with those around them. Over time, these interactions shape the personality traits that emerge later in life.
The formation of abnormal personalities, or personality disorders, is similar to that of normal personalities, with most cases also determined by genetic predispositions and environmental factors. However, research in this area has been more specific. For instance, in terms of heredity, a U.S. study of 1,500 pairs of twins with mental illnesses found that the concordance rate for personality disorders was much higher in monozygotic twins than in dizygotic twins, particularly for certain types of personality disorders. Other studies have found that certain temperamental traits in childhood are linked to specific personality disorders in adulthood. In the UK and the U.S., psychoanalytic theories of personality development were once highly influential, positing that many manifestations of abnormal personality stem from childhood psychosexual developmental disorders interacting with psychological defense mechanisms. Similar to the understanding of normal personality formation, many previously believed that abnormal personality development was primarily determined by environmental factors. However, research in recent decades has shown that while environment (including upbringing) plays a significant role, it is not the sole determining factor. The common observation that siblings raised by the same parents in the same environment can develop vastly different personalities illustrates this point. Abnormal personalities can also result from illnesses, particularly those affecting the frontal lobes (such as traumatic brain injury or encephalitis). Schizophrenia may also present with symptoms of personality disorders, possibly due to frontal lobe dysfunction. These cases, however, are considered residual or secondary symptoms of the underlying diseases and are not discussed in this chapter.
There are also many divergent opinions regarding the classification of personality and personality disorders. The oldest classification by Hippocrates divides personalities into four temperaments, while the simplest classification by Jung categorizes them into two types: introverted and extroverted. Over the past decade, the psychiatric community has largely followed the classification systems of the United States or the World Health Organization (WHO) for personality disorders (not normal personality), and this is also the case in China.
The WHO's *ICD-10* (1992) classifies personality disorders into eight types: paranoid, schizoid, dyssocial, emotionally unstable, histrionic, anankastic, anxious, and dependent. In China, only six types are recognized, excluding the last two mentioned above. These are described in detail below:
**(1) Paranoid Personality Disorder** The main characteristics are hypersensitivity and suspicion, often leading to oppositional behavior. This personality type is not uncommon, but its prevalence is difficult to survey. According to foreign reports, it is more common in men than in women. The primary manifestation is a pervasive, unwarranted tendency to distrust others, believing that others are always belittling or threatening them, being unfair, untrustworthy, or disloyal. Consequently, they do not trust others and are easily angered when they feel wronged. Due to their suspicion, they struggle to establish good interpersonal relationships, even with their own family members.
The diagnostic principles are the same as above. It is essential to rule out paranoid psychosis and suspicions that can be explained by objective reasons.
**(2) Schizoid Personality Disorder** The main characteristics are loneliness and emotional detachment, even within the family. They have no close relationships with others and thus few close friends. Even romantic relationships or sexual activities are approached with indifference. They prefer solitary activities and lack intense emotional expression. They have no clear life goals and lack proficient livelihood skills. Due to their lack of enthusiasm for romantic relationships, men often remain single, while women may marry passively.
Diagnosis is not difficult, but such individuals are rarely considered to need clinical examination. It is important to differentiate from simple-type schizophrenia.
**(3) Dyssocial Personality Disorder** Also known as antisocial or psychopathic personality disorder, this is the most notable type among personality disorders. Its main feature is repeated violations of laws or criminal behavior, though not necessarily intentional crimes. Rather, it stems from a failure to develop a sense of social morality during personality development, leading to an inability to abide by laws. No statistical data on its prevalence is available in China. In the U.S., it affects about 3% of men and 1% of women, with rates as high as 75% among incarcerated individuals. It is more common in impoverished and undereducated communities and among families with similar cases.
Although such individuals often exhibit behaviors like lying, truancy, petty theft, and fighting from a young age, their initial appearance may not be off-putting—they may even have charming looks and expressions, especially toward the opposite sex. They feel no anxiety or guilt about their unlawful behavior, often viewing it as "unintentional" or a "natural reaction." They have no hallucinations, delusions, or thought disorders. They are often articulate, which can lead others to be deceived or exploited by them. They are cold-hearted, ungrateful, and dismissive even of their closest relatives.
The diagnosis must meet the general criteria for diagnosing personality disorders as mentioned earlier. The misconduct must be repeated, not occasional. In addition, there are other forms of misconduct (e.g., violating social ethics without reaching the level of illegality). It should also be noted that because such individuals are skilled in rhetoric, even experienced doctors may sometimes be deceived. When necessary, repeated examinations should be conducted to uncover inconsistencies in their statements.
There is still a lack of effective management measures for antisocial personality. Concentrating such individuals and having them help each other can yield certain results, but these effects cannot be sustained long-term. Incarceration only reduces their harm to society and often has no rehabilitative effect on the individuals themselves. Psychotropic medications can alleviate their secondary anxiety and depressive symptoms and reduce the severity of their impulsive behaviors. Legally, such individuals remain fully responsible for their criminal acts.
(4) Emotionally Unstable Personality Disorder In ICD-10, this type is further divided into two subtypes: impulsive type and borderline type. China’s classification only lists the impulsive type, while the American classification only lists the borderline type. Impulsive personality disorder, also known as aggressive or explosive personality, is primarily characterized by impulsive behavior, often disregarding the consequences, which in reality can lead to serious or relatively severe outcomes. If such behavior is discouraged, it may even escalate to aggressive actions or self-harm. It is often accompanied by emotional instability and unpredictable mood swings. Individuals lack planning and foresight in life, frequently acting on emotional impulses, making them prone to setbacks or failure, yet they struggle to learn from these experiences. They find it difficult to establish stable interpersonal relationships, tending to view others as "all good or all bad," which results in a lack of long-lasting friendships.
The diagnostic principles are the same as for other types, with the main feature being prominent impulsive behavior that is difficult to control. Treatment is challenging, but a harmonious and understanding environment can reduce impulsive episodes (e.g., an ideal family or spouse). Self-control tends to improve with age, leading to a reduction in impulsive behavior by middle age. For those with frequent and severe impulsivity, carbamazepine (0.1–0.2g/day, divided into 2–3 oral doses) may be tried; some reports suggest it can reduce or mitigate impulsivity in certain individuals.
(5) Histrionic Personality Disorder This personality type is characterized by highly exaggerated emotional expression, drawing attention as if performing on stage. Even mundane events can be described or portrayed vividly and dramatically. These individuals are highly suggestible and easily influenced by others or their environment. Although their emotional expressions are intense, they are fleeting, superficial, and changeable. They crave attention and often center themselves in social interactions, paying close attention to appearance and sometimes exhibiting provocative speech or behavior. Minor setbacks can trigger exaggerated reactions. They may pursue momentary emotional satisfaction at any cost or by any means. These traits resemble certain features of hysteria, hence histrionic personality is also referred to as hysterical personality or immature personality.
Diagnosis is not difficult based on the general criteria for personality disorders combined with the above characteristics.
Such individuals rarely seek formal treatment, so research on their treatment is limited. Psychoanalysts believe psychoanalytic therapy is most suitable, while cognitive therapists suggest addressing their overestimated self-evaluation. In general, psychotherapy is the primary treatment option if intervention is sought. Due to frequent feelings of "dissatisfaction," these individuals may fall into low moods or even depression; phenelzine has been reported to be effective in such cases.
(6) Obsessive-Compulsive Personality Disorder The hallmark of this personality type is an insistence on everything being orderly, perfect, and adhering to various rules—even minor details—resulting in rigid behavior and low efficiency. This personality typically forms during adolescence. It manifests in various ways: some individuals exhibit excessive doubt and caution; others become overly preoccupied with rules and regulations; some pursue perfection to such an extent that they fail to complete tasks on time (for example, when asked to draft a plan, they endlessly revise it in pursuit of perfection and miss deadlines); some are overly conscientious, excessively cautious, and place too much emphasis on work, impairing their professional and social lives; others are excessively pedantic, rigidly adhering to social conventions and unable to adapt flexibly in special circumstances; some are extremely inflexible and stubborn; and some not only behave rigidly themselves but also demand others to follow their ways, thereby damaging interpersonal relationships. In summary, individuals with obsessive-compulsive personality often lose sight of the "big picture" due to their focus on details—for instance, missing a flight because they spent too much time inquiring about boarding procedures.
The diagnosis is not difficult, but if the patient has a specific sociocultural background, attention must be paid to differentiation. For example, non-believers should not mistake certain rituals that believers must diligently perform as "stubbornness or rigidity."
Obsessive-compulsive personality is not uncommon. According to U.S. data, its prevalence is about 1% of the general population, while among psychiatric outpatients, it can be as high as 3–10%.
Although diagnosing this personality type is not difficult, treatment is challenging. Psychotherapy is the primary approach, but its effectiveness is uncertain. Most individuals may not necessarily seek treatment. Some suggest applying the principle of "reversal of extremes" in therapy—for instance, asking a perfectionist to be "even more perfect" or "more meticulous," thereby helping them recognize the excessiveness of their original behavior before they can correct it.
The six personality disorders mentioned above are merely representative. Sometimes, a single individual may exhibit characteristics of more than one personality disorder.
Everyone has their own personality traits, but what kind of traits or to what extent they become prominent is considered a personality disorder? This is a diagnostic issue. To date, this problem has not been fully resolved. First, there is the issue of overlap or transition between abnormal and normal traits, which is a matter of degree. Some suggest that if such personality traits cause difficulties in social adaptation, they can be called a personality disorder. This is a rather vague but frequently applied definition. This definition involves too many variables, making its reliability and validity difficult to determine. Second, there is the boundary issue between personality disorders and mental illnesses. As mentioned earlier, personality is a stable and enduring trait, but in clinical settings, it can sometimes be difficult to distinguish from the chronic or early stages of certain mental illnesses.
Although it is theoretically or definitionally challenging to draw a clear line between personality disorders and the normal or pathological states, for an experienced doctor, diagnosis is usually not difficult in most practical situations.
The diagnosis of a personality disorder should generally meet the following criteria:
1. The origin of this behavioral pattern can be traced back at least to adolescence and is persistent.
2. The characteristics of this manifestation are persistent and pervasive, reflected in most behaviors.
3. Due to this manifestation, it affects either the individual's or others' work, life, or learning, or both.
4. The individual often does not recognize this as a defect or considers their behavior理所当然; some may acknowledge it verbally but find it difficult to change.
5. These personality traits are not caused by other illnesses or severe objective events.
6. The individual must be an adult (generally over 18 years old), as personality disorders are not typically diagnosed in children or adolescents.
