According to the DSM-5
A personality disorder is an enduring pattern of inner experience and behavior that deviates markedly from the expectations of the individual's culture, is pervasive and inflexible, has an onset in adolescence or early adulthood, is stable over time, and leads to distress or impairment.
So firstly, a personality disorder is a maladaptive pattern of inner experience and behaviour.
The DSM-5 goes on to specify four domains which can be affected by having a personality disorder:
- Affect (emotional states)
- Cognition (how a person sees and interprets themselves, other people, and life events)
- Interpersonal functioning (relationships)
- Impulse control (sex, drugs, rock & roll…but also fast cars, credit cards, chocolate binges)
Secondly, to be diagnosed with a personality disorder the behaviours need to deviate markedly from the expectations of the individual's culture. So consider the patient's cultural background and what might be normal for them. You may also want to ask their family, or consult cultural liaison.
Thirdly, the condition should be pervasive and inflexible. It should be obvious across a range of social and personal situations, e.g. home, school, work, personal life.
Fourthly, the condition should be stable over time, with onset in adolescence or early adulthood (when our personalities are generally set).
Traditionally personality disorders have been viewed as lifelong; but as far as recent research goes, the jury is out. People can and do change although there is truth in the saying “it is hard to break the habits of a lifetime”.
Finally, the condition should leads to distress or impairment. Or else it wouldn't be a disorder!
Note that you don't have to have both distress and impairment. In fact, many personality disorders are what we call ‘ego-syntonic'; the person may not feel that there is a problem.
For example, a person with “schizoid personality disorder” might be perfectly happy living alone in a shack in the outback and seeing other humans once a year.
Its not me who has the problem.
Its everyone else.
THE WEIRD, THE WILD, THE WORRIED
Traditionally there have been 10 major personality disorders, divided into three clusters.
Cluster A (the weird):
Cluster B (the wild):
Cluster C (the worried):
There are plenty of websites and blogs that summarise the ten personality disorders. (This overview at Psychology Today is comprehensive.)
So I won't go into the nitty gritty of this; but I will outline, based on my admittedly subjective and totally unvalidated clinical experience, which personality disorders you are likely to encounter in your psychiatric rotations as a medical student or JMO:
1. Borderline Personality Disorder (there is a 100% chance you will encounter at least one person who has been diagnosed with BPD during your clinical rotation. Unless your attendance is shocking.)
2. Antisocial Personality Disorder (again, you have pretty good chances of encountering a person with this condition)
3. Personality Disorder Not Otherwise Specified (aka “I Know There's Something Wrong But Not What It is.” Not one of the ten, but a very frequently applied diagnosis)
Additionally, you're likely to notice personality traits among the majority of your patients – not surprising, since developing acute mental illness tends to exacerbate underlying personality vulnerabilities. Furthermore, personality disorders are highly co-morbid with a range of mental illnesses, making diagnosis challenging.
People with a Cluster A condition do not usually present to mental health services; however, when they do, a frequent differential diagnosis (and/or co-morbidity) is schizophrenia. Cluster A personality traits can also appear to resemble autism spectrum disorders at times.
As is the case for the the Disorders themselves, you are most likely to encounter patients in your psychiatry who have been diagnosed with borderline and antisocial personality traits, but who may not meet full criteria for personality disorder.
You may also encounter the occasional patient with histrionic or narcissistic personality traits – although beware making hasty judgments about people's personalities when they are unwell. For example, patients with bipolar affective disorder often appear quite grandiose (and therefore narcissistic and histrionic) when they are acutely unwell with mania!
Substance use disorders are also frequent in this grouping.
People with avoidant and dependent personality traits can be vulnerable to developing depression and anxiety and often present with this. Additionally, people with obsessive-compulsive personality traits often become doctors (You may find that your consultant psychiatrist has significant obsessive-compulsive personality traits. Or perhaps your registrar or intern. Or perhaps you.)
The academic battle was long and bloody, but finished with the publication of DSM-5 in 2013.
In the end, the traditional classification system was retained, while the proposed new ‘trait model' was relegated to a twenty-page appendix at the back of the DSM-5.
Categorical versus dimensional, or the DSM-5's biggest drama
You'll notice I haven't talked about normal personality (as opposed to personality disorder) in this blog post.
This is is because personality research is both:
a) extremely complex, and
b) mostly irrelevant to Australian medical school exams.
However, its worth breaking for a minute to discuss this topic. Personality refers to individual differences in characteristic patterns of thinking, feeling and behaving. A person’s personality is generally considered to develop from a combination of genetic traits and environmental influences. Personalities (just like personality disorders) are generally seen as predictable and inflexible, whether they are considered part of a disorder or not.
The dominant way of thinking about personality these days is the five-factor model. This is a dimensional model which describes people as falling on a continuum in terms of five major traits, summarised by the acronym OCEAN:
- Openness to Experience
By contrast, psychiatry has historically taken a categorical approach to describing personality disorders.
There were numerous controversies and disagreements surrounding the publication of the DSM-5, so much so that a recent book dubbed it “the psychiatric Babel”; but the loudest and most hotly contested discussion centred on whether psychiatrists should be taking a dimensional/trait approach to personality disorders.
After all, is it meaningful to claim that personality disorders are categorically different from normalcy, when they possibly or probably represent extremes on a continuum of human behaviour? Or when in fact there is a movement to reclassify some Personality Disorders as trauma-related conditions.
The academic battle was long and bloody, but finished with the publication of DSM-5 in 2013. In the end, the traditional classification system was retained, while the proposed new ‘trait model' was relegated to a twenty-page appendix at the back of the DSM-5.
There was a small victory, however. Personality Disorders were elevated from being on a separate axis to being considered in the main catalogue of conditions.
And the debate is far from settled. The DSM-5's main competitor, the World Health Organization's ICD-11, is coming out in 2018 and is rumoured to be incorporating aspects of of the trait/dimensional model in its classification of personality disorders. Or maybe not. Keep watching this space.
In Part II on personality disorders, I'll talk about assessment and management, as well as the role of stigma. Most of this will be with reference to borderline personality disorder, one of the most infamous and ubiquitous diagnoses in psychiatric settings.
SOME VERY OPTIONAL READING, FOR THOSE INTERESTED:
- Kendall RE. The distinction between personality disorder and mental illness. BjPsych, 2002 (180) 110-115.
- Davis JL. Personality Disorders can change with age. WebMD, 2004
- Parking lot of the personality disordered. Medical Humor WordPress Blog
- McRae RR, John OP. An introduction to the five factor model and its implications. www.workplacebullying.org