Welcome!

Welcome to my blog, a place to explore and learn about the experience of running a psychiatric practice. I post about things that I find useful to know or think about. So, enjoy, and let me know what you think.


Wednesday, September 18, 2013

HAM-D'ing It Up

Last month I published a post entitled, Lifelong Learning-A New Frontier. In it, I introduced the idea of an online journal club, and I threw down the gauntlet with a challenge-let's talk about this paper:

A Rating Scale For Depression, by Max Hamilton

So here I am, talking about it. In written form.

In case it isn't obvious, this article introduced the Ham-D, or Hamilton Rating Scale for Depression, which is still in use.

And in case you happen to think there's something new under the sun, the paper begins with, "The appearance of yet another rating scale for measuring symptoms of mental disorder may seem unnecessary, since there are already so many in existence and many of them have been extensively used."

The year is 1960.

I'm gonna go on to delineate some random thoughts and reactions to the paper, in the hope that this will encourage dialogue, as might take place in an in-person journal club.

The first thing old Max H does is describe the purpose and appropriate usage of this particular rating scale. Or more accurately, what it's purpose isn't:

1. It's not devised for normal subjects
2. It's not self-rating
3. It's not about social adjustment/behavior
4. It's not broad range

Rather, it focuses on the measurement of symptoms in individuals already diagnosed with depression.

The present scale has been devised for use only on patients already diagnosed as suffering from affective disorder of depressive type. It is used for quantifying the results of an interview, and its value depends entirely on the skill of the interviewer in eliciting the necessary information… It has been found to be of great practical value in assessing results of treatment.

One question I have is, who makes the diagnosis? And based on what diagnostic system? The DSM-II was published in 1968, which means the HAM-D was developed to assess depression in people who may or may not have met the DSM-V criteria for Major Depression, were they being assessed today. So is it still appropriate to use the scale?

The scale includes 17 variables related to depression, plus 4 additional variables, diurnal variation, derealization, paranoid symptoms, and obsessional symptoms, that are either related to type rather than severity or intensity of depression (diurnal variation), or are seen only rarely in the context of depression (the other three). Each variable is rated on either a 5 point (0-4) or a 3 point (0-2) scale, with the latter in use when quantification is difficult, e.g. insomnia and agitation. It's interesting to note that on the modern HAM-D form, agitation is measured on a five point scale, which Hamilton found "impracticable".

The scale was written with the intention of having a given patient rated by two different raters. Where only one rater is available, the score should be doubled.

Some caveats for the raters:

1. No distinction is made between intensity and frequency of a symptom-the rating is at the discretion of the rater, who is expected to take both into account.
2. Depressive Triad: depressive mood, guilt, suicidal tendencies-the rater needs to avoid a  halo effect, e.g. giving guilt and depressive mood the same rating because they're closely related.

Table 1 is the correlation matrix.




It's how well each individual symptom correlated with each of the other individual symptoms. So, for example, Depression has a 1.0, since it correlates 100% with Depression. Guilt correlates with depression 49.1% of the time, and 100% with Guilt, etc.

This is followed by the extraction of some data, summarized into 4 factors-not sure how these are obtained.
As I understand it (poorly), factor analysis is a way to take your data and look at it as fewer variables than you started with. I briefly perused the Wiki Article, which seemed to involve some Linear Algebra. And since it's been many a year since I was intimate with eigenvectors, I'm gonna leave it at that. In other words, it's magic.

But, for example, Factor 1 has high correlations with depressed mood, guilt, suicide, delayed insomnia, work and interests, retardation, genital, and insight; And low correlation with agitation and anxiety, so they call it a "retarded depression"
This, so the article claims, corresponds well with the classical description of depression.

Which one? Melancholia? Seems like.

Finally, the end of the paper includes several case descriptions, not just scores. This is in stark contrast to today's style. I suppose this is knowable, but I don't know it-were most papers written with case descriptions then?

Please comment so we can get a discussion going. It's a short paper. Check it out.