On Slate’s DoubleX website, Dr. Peter Kramer posts an article joining the DSM V debate.

The APA’s attempt to keep the decision-making process secret is indefensible. The other matter, whether the diagnostic system needs and is ready for revision, is extraordinarily complex.

Kramer is writing a book on the way psychiatrists diagnose patients, and focuses the bulk of his post on this.

A fundamental change in the way that informed psychiatrists see the project of outlining and justifying diagnoses. Psychiatry has, by and large, dropped the illusion that its diagnoses are what philosophers call “natural kinds.” A natural kind is something that simply exists in nature.

This makes it hard.  There isn’t a specific test: the presence of a bacteria (or its antibodies), a virus, a gene, that identifies the mental illness. This is true in many areas of medicine.

Even for a near-universally accepted disorder like schizophrenia, a unifying cause will prove illusory.

High blood pressure and asthma are legitimate diagnoses even though their causes are diverse, and reasonable observers disagree on the conditions’ lower limits. And good diagnoses have “predictive validity”: they suggest how disorders will progress, which symptoms they will produce, and which remedies will ameliorate them.

The cause of the illness doesn’t have to be unifying or unique or single, but the illness itself  has to be consistently recognizable.  A lot of the controversy has to do with the conditions’ lower limits.  Take depression for example.  The lower limit from the point of view of time is two weeks … if your blues persists for two weeks then you have depression.

In the first year after my tragedy, when I was seeing both a psychiatrist and psychologist, they were constantly testing me (by interviewing me, watching my reaction … not by taking blood) to see if I was falling into depression.  Did I have good days between the bad days?  Did the amount of bad days slowly ebb over time?  What did I do on my bad days?  Did I play tennis?  Did I eat?  Did I talk to anyone?  This was a major, recurring theme in my grief therapy.

Yes the criteria seems a bit arbitrary: why 14 days instead of 10 days, 20 days, 5 days?  Just because professionals in the field may debate the time period strenuously doesn’t mean that ultimately they don’t agree that one has to exist.  You have to start somewhere.  Every individual is different, but there has to be yardstick.  In the DSM the APA has to take a position

For all its flaws we can’t do without diagnosis. Think of a patient who comes to a doctor after a series of panic attacks and is reassured: “You don’t have heart disease. You won’t die from these palpitations. We have ways to treat panic, with medication or psychotherapy.” Or think of a parent whose child has anorexia and learns that the condition is life threatening. We need to be able to name the thing—panic disorder, anorexia—and convey what we know about it. Similar requirements exist for research. Schizophrenia in Verona must be schizophrenia in Boston.

We need to be able to name the thing.