Here’s a question. As you sit across from your patient, what or whom are you treating: Ms Smith’s bipolar illness, or Ms Smith, a person with bipolar illness? The DSM leans toward the first choice. The manual classifies diagnoses and disorders, not people. This is fitting with the medical model, according to which a medical nosology includes hypertension and diabetes, not the individuals who suffer from them.

Is there then any difference between a medical diagnosis and a psychiatric diagnosis? Granting the many exceptions to this generalization, could we say that a psychiatric diagnosis is more wrapped into the personality of the patient than a medical diagnosis—Ms Smith’s bipolar condition more imbricated into her personality than Mr Jones’ hypertension into his. Mr Jones, after all, can distance himself from his condition, not think about it, and not even know he has it. That will all be harder for Ms Smith. Denial of a symptomatic mental disorder is not quite the same as total ignorance of a silent hypertension.

Identifying a patient by his or her DSM diagnosis is often like choosing a cheap suit off the bargain-basement rack. The fit is awkward and uncomfortable, and we would like to offer our patients a more tailored look.

So we would choose the second of the above choices: we are treating Ms Smith, a person with bipolar illness. We recognize both the individual person and the diagnostic category, and we recognize that one person’s bipolar illness looks quite different from another’s. The one-size-fits-all style of medical nosology doesn’t work very well with our psychiatric patients.

DSM-IV makes some effort to capture the particularity of the individual patient with 2 strategies. The first is the multi-axial system, the third and fourth axes adding more information about the patient. The second strategy is co-morbidity. Adding a second and even third diagnosis distinguishes patients who share a primary diagnosis. These strategies are of course not very effective; and indeed, co-morbidity is considered something of a curse of DSM-IV.

The authors of DSM-5 are taking another approach to making our diagnostic suits fit a little better. They are trying to loosen the rigidity of the categorical diagnoses with the use of dimensions—dimensions for individual diagnoses and the cross-cutting dimensions. Diagnostic categories are the cheap suits off the rack; dimensional diagnoses are the finely tailored suits. Or so they are claimed to be. It remains to be seen how well they will fit our patients, if by that we mean, how well they will capture the particularity of the patient—or, to address the title of this piece, whether they will bring the missing person back into the DSM.

These efforts of DMS-IV and DSM-5 are nothing compared to a project of the World Psychiatric Association to develop a series of International Guidelines for Diagnostic Assessment (IGDA).¹ One of the guidelines, IGDA 8, titled “Idiographic (Personalised) Diagnostic Formulation”² recommends an idiographic component to the diagnostic formulation.“³ The diagnosis itself should combine a nomothetic or standarized diagnostic formulation (ICD-10, DSM-IV) with an idiographic (personalized) diagnostic formulation reflecting the uniqueness of the patient’s personal experience. At the nomothetic level, a multi-axial diagnostic formulation is recommended. For the idiographic formulation, an integration of the perspectives of the clinician, patient, and family should be presented in natural language.”^4[p.41] The “idiographic” guideline provides 10 pointers for developing the formulation, along with a model page format.

The IGDA guidelines, with the idiographic component, go a long way toward addressing the problem described in this article. They are, however, an ambitious, not to say quixotic, project, given that the evaluation of a patient following the IGDA guidelines would require hours. In the real world of hurly-burly clinical practice, it is difficult to imagine busy clinicians being able to follow these guidelines.

So where does this leave us with the missing person in the DSM? I will propose an answer in my next blog.

References
1. Mezzich JE, Berganza M, von Cranach M, et al (eds). Essentials of the World Psychiatric Association’s International Guidelines for Diagnostic Assessment (IGDA). Br J Psychiatry Suppl. 2003;45:S35-S66.
2. IGDA Workgroup, WPA. IGDA. 8: Idiographic (personalised) diagnostic formulation. In: Mezzich JE, Berganza M, von Cranach M, et al (eds). Essentials of the World Psychiatric Association’s International Guidelines for Diagnostic Assessment (IGDA). Br J Psychiatry Suppl. 2003;45;S55-S57.
3. Phillips J. Idiographic formulations, symbols, narratives, context and meaning. Psychopathology. 2005;38:180-184.
4. IGDA Workgroup, WPA. IGDA. 1: Conceptual bases—historical, cultural and clinical perspectives. In: Mezzich JE, Berganza M, von Cranach M, et al (eds). Essentials of the World Psychiatric Association’s International Guidelines for Diagnostic Assessment (IGDA). Br J Psychiatry Suppl. 2003;45;S40-S41.