Numbers

Numbers have a special power, it seems, but their power is not always beneficial.

I see the effect of numbers particularly strongly when I prepare a legal report. I write it as a normal document, so that it is easy to read and review. After picking over the text to make sure that it says everything it is meant to say and nothing more, I add the legal boilerplate — the text that every report has to have.  At this stage it still looks dull and uninspiring.

The final touch is to double-space the whole thing and number the paragraphs. Suddenly, with the numbering, the document looks powerful and impressive.

In reality there might be no particular reason why paragraph 2.4.3, say, should come after paragraph 2.4.2 and before paragraph 2.4.4, but the numbers make it seem that each paragraph has an important place in the scheme of things.

I sometimes wonder what this embedded falsehood in legal documents implies about the work of the courts…but I digress. This post is not about the law, it is about borderline personality disorder, BPD.

BPD

In many versions of the DSM-IV description of borderline personality disorder, there are numbered paragraphs. Why? In reality the criteria are in no particular order.

The effect of the numbering is to make the numbered paragraphs seem important. And in doing that, the numbers make unnumbered paragraphs seem unimportant.

For an example of what I mean, see Wikipedia. For another (no better) presentation of the same text with bullets instead of numbers, see PsychNet.

So there’s a temptation, when reading the criteria, to ignore the part at the beginning that has no numbers. To understand the criteria properly, you must deliberately ignore the false sense of importance that the numbers convey, and take full account of the unnumbered part.

When you do that, the criteria look very different.

The central statement that defines BPD, according to the DSM, is that it’s:

A pervasive pattern of instability of interpersonal relationships, self-image, and affects, and marked impulsivity…

Primary criteria

So the primary criteria for BPD are:

• Pervasive — that is, diffused throughout every part of the person’s life
• Instability — that is, a randomly changeable or fluctuating quality
• Impulsivity— that is, acting without forethought to a marked or surprising degree

And the pervasive instability affects all three of the following things:

• Interpersonal relationships — which is what makes this disorder a personality disorder
• Self image
• Affects — that is, emotions

There is no point in considering the secondary criteria (the numbered list) if the primary criteria are not met.

Examples

Here are some (fictitious) examples:

Anne has unpredictable moods that sometimes cause extreme behaviour. She has never been able to hold down a job for very long, or have a lasting relationship with a boyfriend. Her relationship with her parents has been stormy since her early teens. But she has always got on reasonably well with her brother, and she keeps in touch with one or two school friends whom she has always trusted. So Anne has some stable relationships. Her instability is not pervasive. She does not have BPD.

Bill has a history of violence and no close friendships. He does not associate with other family members at all. He sees himself as an outcast. Feelings of anger and hopelessness are a constant background to his life, and they sometimes overwhelm him. So Bill’s self image and mood are stable (which does not mean that they are good). Bill does not have BPD.

Cath has been certain she has BPD since she found out about it five years ago. She feels she has no stable relationships (though her friends would not agree), and that she causes disruption and pain to her family (though her family would not agree). For the past two years she has been active in a BPD support group where she feels that her experience is of benefit to other members. So Cath’s relationships and self image are extremely stable, which (ironically) means she does not have BPD.

Dick makes friends easily and has landed some impressive jobs, though neither friends nor jobs have lasted.  He is full of hope when he describes his plans for the future, but he despairs that he has constantly been thwarted in life by other people’s stupidity. He feels extremely angry at his family for failing to support him, though he often visits his parents and writes long letters to his sister. Dick’s relationships, self image, and mood are all unstable all of the time. Dick might have BPD…but only if he meets the secondary criteria.

Secondary criteria

The first of the secondary criteria is “beginning by early adulthood”. So if you have had some years of adult life without pervasive instability, any mental illness that you develop after that is not BPD.

The next secondary criterion is “present in a variety of contexts,” which means pretty much the same as “pervasive” and so can be ignored — if, that is, you took full account in the first place of what “pervasive” means.

The other secondary criteria are the numbered ones. These criteria only have significance if they are indications of primary criteria. The words in the DSM are “as indicated by“. The secondary criteria have no significance in themselves, so you can meet any number of them and still not have BPD if you don’t meet the primary criteria.

Traits

A common way in which the number secondary criteria are misused is by describing them as traits or characteristics in themselves, when they are in fact no such thing. This kind of misuse of the criteria results in people being labelled “borderline” when they do not have any personality disorder at all, and sometimes even when they do not have any mental illness at all.

For example, one of the numbered criteria is:

Frantic efforts to avoid real or imagined abandonment.

“Frantic” means apparently insane or out of control.

Edna’s mother tells her she will not be able to go with her to the doctor this week, and Edna reacts by shouting at her mother and storming out, slamming the door.

Fred’s mother tells him she will not be able to go with him to the doctor this week, and Fred reacts by falling to the floor sobbing, then crawling over to his mother and clinging to her left leg, begging her to change her mind.

Fred’s reaction is frantic, consistent with BPD, while Edna’s is not. Plenty of sane people shout and slam doors.

Also, Fred’s frantic reaction is only worth noting as an indication of the primary criteria. It is meaningless in itself if the primary criteria are not met. Even perfectly sane people can occasionally become frantic.

Neurosis

Misuse of diagnostic criteria is a neurotic behaviour on the part of some mental health professionals. By ‘neurotic’ I mean a behaviour that is harmful in the long term, but that is maintained because it is rewarding in the short term.

The reward in this case is that suggesting a patient has a personality disorder that is very difficult to treat lets the mental health professional feel better about providing inadequate treatment. The harm is that the mental health professional’s skill level actually goes down over time as effective but difficult treatments are replaced by ineffective but easy misdiagnostic subterfuge. (And, of course, there’s the harm done to the patients…)

CBT therapists in private practice who succumb to this kind of neurosis will quickly go out of business as they stop getting referrals. So this kind of thing is mostly seen in practitioners who are employed by organizations, and whose employers (the NHS, for example) do not measure individual practitioners’ outcomes.

Measuring outcomes would mean keeping records and interpreting the numbers to hold professionals to account in the same way that the market does for private practitioners. That would be a much better use for numbers.