Causes and Effects of Personality Disorder

The phrase “personality disorder” sounds more dramatic than it really is. People imagine someone out of touch with reality, even bordering on psychosis. In fact, personality disorders are very common, affecting between five and 20 per cent of the population.

The Personality Disorder and the Flawed Personality

The notion of a “personality disorder” confuses many people. After all, everyone has a personality, and it is never flawless. Even the most stable, well-rounded individual still has their moments of paranoia, anxiety and obsession. Given that, what makes one personality disordered and another merely flawed? In other words, where do you draw the line?

The answer is that drawing such a line is difficult. A 2010 UK study concluded that the majority of people have “personality difficulties” but do not quite meet the threshold for a personality disorder. For example, the “histrionic” person is vain, shallow, dramatic and attention-seeking. Almost everyone knows such a personality. Indeed, there is probably someone in your family who matches that description. The chances are, however, that they do not have a full “histrionic personality disorder.”

The Diagnostic and Statistical Manual of Mental Disorders currently recognizes ten distinct personality disorders: the paranoid, schizoid, schizotypal, antisocial, borderline, histrionic, narcissistic, avoidant, dependent and obsessive-compulsive. These are further grouped into clusters: the paranoid, schizoid and schizotypal in cluster A; the antisocial, borderline, histrionic and narcissistic in cluster B; and the avoidant, dependent and obsessive-compulsive in cluster C.

To qualify you would need to possess specific traits. You would also exhibit them at an early age. And they would have had a big impact on your life. In particular, they would have affected your ability to work, take care of yourself and form intimate, lasting relationships.

How the Personality Disorder Affects Your Life

First, a personality disorder affects the way you think. For example, someone with a narcissistic personality disorder thinks he is superior to others. When John’s work colleagues tell him they can no longer stand his arrogance, he dismisses it as jealousy. Later, someone writes a letter to the manager saying John’s attitude is intolerable, and everyone signs it. John is then called in to explain himself. He thinks it over and decides that his talent and skill make his colleagues feel inferior. They have complained, John argues, because his abilities and intellect make them look bad.

In the office across the street, however, Kate suffers from a paranoid personality disorder. Her colleagues mostly like her, but that’s not what Kate thinks. Instead, her paranoia makes her guarded and suspicious. One day a new worker starts, someone chatty and extrovert. Soon, she has made friends with two young women who sit close by Kate’s desk. At lunch they gossip and laugh. Within no time Kate convinces herself they are laughing at her.

A personality disorder also affects the way people behave. And their behaviour, like their thoughts, settle into recognisable patterns, often at an early age. For example, someone with an anti-social personality will be destructive and rebellious at school. And when they act it is often without thought for the consequences. In their teenage years, they are the one who jumps over the electric fence to play on the train tracks. And as adults their behaviour escalates, leaving behind a trail of crime and failed relationships.

A personality disorder affects one’s emotions as well, not only their nature but their range, depth and intensity. And people with personality disorders also exhibit odd or inappropriate emotions. In other words, their rage, or fear, or pessimism is abrupt and strange, often leaving others shocked and confused. The paranoid, for example, may grow to hate a gentle and harmless neighbor. An avoidant personality, on the other hand, shakes with fear during lunch with her boyfriend’s parents.

Unsurprisingly, the number and nature of these personality disorders is still debated. While the DSM recognises ten, many others have been proposed, such as the passive-aggressive personality disorder, in which the individual is sullen and difficult, undermining others in subtle, indirect ways. Others proposed include the “depressive,” “sadistic” and “self-defeating.” To complicate things, the American Psychologist Theodore Millon suggests numerous sub-types, such as the “insular paranoid” or “remote schizoid.”

Finally, people rarely tick every box for just one personality disorder. Comorbidity is very common, with certain personality disorders often found together. For example, people with avoidant personalities tend to be dependent and paranoid, while the borderline often display antisocial traits.


Obviously, the causes vary from person to person, but genes, parenting, early deprivation and physical or sexual abuse all play a part. The link between genes and personality disorders is poorly understood and still in its early stages. Individuals do not inherit a full-blown histrionic, schizoid or avoidant personality. Instead, we inherit certain traits, such as anxiety or aggression. In themselves, these do not guarantee a personality disorder. But should someone inherit a vulnerability to stress, for example, along with an anxious, introverted nature, an avoidant personality is more likely.

The environment in which someone is raised also plays a part. The person in the example above is anxious and introverted; if she is then raised at the heart of a big, loving family in a house that is open to the world, she will learn to cope. She remains anxious and introverted, but she does not develop a personality disorder. Now imagine she is raised the only child of a depressed and socially isolated single mother. They have no money, and she is often ridiculed for her dirty, shabby clothes. Because she has never been properly socialised, her anxiety grows worse and develops into a social anxiety disorder. The humiliation she feels at her scruffy apartment, her mother’s alcoholism and the lack of money, makes her withdraw into herself and avoid others. Intimacy soon becomes associated with shame. The answer is to avoid intimacy!

Parenting has a big influence. In the early years our mother and father are models. We tune in to their moods, absorb their outlook, sometimes even imitate their body language. This is known as ‘learnt behaviour’ and, if extreme enough, can lead on to a personality disorder. Simple neglect also plays a part. Research suggests that those with a borderline personality disorder often failed to bond with their mother. But too much attention can be just as harmful. A little girl whose parents spoil and over-praise her is more likely to develop a histrionic personality disorder. She was made to feel like the centre of the world; she then leaves home, enters school or the workplace, and is shocked to discover that others do not share this opinion. And so she becomes melodramatic and attention-seeking.

Childhood abuse is also common. The sexually abused are three times more likely to develop a personality disorder. Physical abuse (parents or step-parents who beat them), on the other hand, often leads to anti-social personalities. Everyone knows a boy from a violent, dysfunctional family who vandalises bus shelters and storms out of school lessons. Even the emotionally neglected or verbally abused are more likely to develop narcissistic, paranoid and obsessive-compulsive personality disorders than the average person.

Overcoming a Personality Disorder

Looking at a personality disorder from the outside is very difficult. For example, one of the differences between an avoidant personality disorder and social anxiety is that the avoidant do not recognize that anything is wrong. The socially anxious accept that socializing triggers fear and that this affects their life. The avoidant, on the other hand, argue that they don’t want to socialize because they don’t feel like it, or that they don’t like other people. They are also more inclined to shrug and say “this is who I am; there’s nothing I can do about it.”

First, make an effort to thoroughly understand. If you have been diagnosed with a personality disorder, or suspect that you have one, read all you can. And don’t just read about your personality disorder. Remember, personality disorders involve a great deal of comorbidity. In other words, you rarely find an obsessive-compulsive personality who doesn’t also have paranoid, dependent or avoidant traits; someone with a borderline personality disorder is likely to have antisocial traits, while histrionics often have narcissistic traits, and so on.

If you suspect you have a personality disorder, you could begin with therapy. There are many different types of therapy available, and obviously there are many different therapists. A word of caution, however. Therapy is not like surgery. In other words, if you need your appendix removed, it doesn’t really matter which surgeon performs the operation. He or she could be rude, boring, unpleasant, arrogant, etc., but so long as he does a good job it doesn’t matter. With therapy that is not true. There needs to be trust and respect, so keep searching until you find someone with whom you feel comfortable.

Finally, be careful not to over-diagnose. People with personality disorders often suffer a great deal. Then they receive a diagnosis. At last, they think, it all makes sense. But individuals remain individuals. Two people with antisocial personality disorders still have their own character traits. They’ve been raised by different parents, inherited different genes, had different experiences, etc. Though they have a great deal in common, they will not be identical. So don’t convince yourself you have every symptom.

Once you are clear on the precise nature of your personality disorder you can begin working on it. The brain is now known to be malleable, constantly laying down new networks or pathways in response to new experiences. And even our genes can be switched on or off.

The Danish journalist Lone Frank, who has a PhD in Neurobiology, wrote an interesting book on this subject called My Beautiful Genome. In an interview, she remarked that though she inherited genes that made her vulnerable to depression and anxiety, this knowledge comforted her. When she feels depression creeping up, she knows it isn’t her fault and that she needs to avoid stress and eat healthily. But, she remarks, “though our hereditary material is locked in, our brain is extremely versatile,” adding that “the more you know about it, the more you can influence it.”

For example, if you have a paranoid personality disorder, you will interpret everything in a biased way. And you will disregard anything that doesn’t fit your model of the world. Paranoid personalities, like depressives, expect the worst. If they drive across country for the family vacation, they expect something to ruin it: the car will break down, a tire will blow, it will rain all summer, etc. When none of those things happen, they disregard it. When a tire does blow, however, they never forget, taking it as proof that the universe is against them.

Every time you question your beliefs, or challenge harmful patterns of behavior, you counter your personality disorder. To take a final example, if you have an avoidant personality, try going against your avoiding instinct at every opportunity. Walk to the middle of the dance floor, or the back of the store, or whatever it may be, reciting to yourself over and over “I don’t care what people think of me…it doesn’t matter what people think of me.”

Personality disorders are no joke. Indeed, they harm countless lives. And it isn’t only the victim who suffers. Having a child with an antisocial personality, or a father with a paranoid personality, etc., is no fun. The good news is that personality disorders can be reversed. The bad news is that, like so many things in life, it demands hard work.

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Mark Goddard, Ph.D.

Mark Goddard, Ph.D. is a licensed psychologist and a consultant specializing in the social-personality psychology. His publications include magazine chapters, articles and self-improvement books on CBT for anxiety, stress and depression. In his spare time, he enjoys reading about political and social history.

*The views expressed by Mr. Goddard in this column are his own, are not made in any official capacity, and do not represent the opinions of his employers.

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