Sunday, March 12, 2006

Reports on D-Cycloserine

Posting may be a little on the light side here, over the next 10 days or so.  In fact, if there are any aspiring bloggers out there who might want to try blogging, but don';t have their own blogs, and who are interested in neuroscience or progressive politics, let me know in the comments.  Perhaps you could be a guest blogger for a few weeks, give it a try, to see if you want to start your own.  Just leave a note in the comments section.  Don't be shy, now...

Speaking of shyness, there is another report out about the use of D-cycloserine (DCS)for treatment of Social Phobia, AKA Social Anxiety Disorder.  I blogged out that a while back, after a small pilot study was done.  And now we have...another small pilot study.  (Drug development is like that sometimes.)  The more recent study is a little different, though.  The first one looked at treatment of simple phobia.  Simple phobia generally does not require drug treatment, so the original study was more of a proof-of-concept kind of thing.  In contrast, finding a new, good treatment for social phobia would be a significant advance.

The original study was published in Arch Gen Psych, here.  Unfortunately, you don't get to see the full article without a subscription.  There are additional reports available, both of which give slightly different subsets of information (1 2).  

Because I am trying to get to be less compulsive, I am not going to recap the study.  You can just follow the links and read the articles and the abstract, then read my commentary.

The first comment I have is that the articles are a little misleading about the significance of the study.   They mention that social phobia can be rather serious.  From the #2 link:
Social Anxiety Disorder is the third most common psychiatric condition in the U.S. behind depression and alcohol abuse. If left untreated, the disorder typically follows a chronic, unremitting course that can lead to substantial impairments in vocational and social functioning.
That certainly is true.  Social phobia can be a career-threatening condition.  It can lead people to get stuck in bad -- even dangerous -- relationships.  It can lead to chronic under-employment, or overt unemployment.  Now, I know that it sometimes has been disparaged as a made-up disease; just as Hallmark invented Secretary's Day to sell greeting cards, some people allege that drug companies have invented Social Anxiety Disorder to sell drugs.  I am not going to argue that point now.  You will have to trust me; it is real, and in some cases, it is debilitating.  

The thing is, the study only showed short-term benefit for persons with public speaking anxiety.  While it is true that anxiety with public speaking is a form of social phobia, in fact it is a lot more like a simple phobia.  Most patients with serious social phobia have much more pervasive anxiety and avoidance behaviors.  Showing that something helps with a specific type of performance anxiety is interesting, but from a clinical standpoint, it is not very exciting.  We already have Xanax for that kind of problem.

My second comment is this: DCS is an antibiotic used for tuberculosis.  Widespread use of that could lead to drug resistant strains, and drug resistant TB is already a big problem.  We most certainly do not want to do anything to make that problem worse.  I would want to see a lot of careful analysis, to be convinced of the wisdom of using DCS for social phobia.  

My third comment is this: If someone is looking for a blockbuster drug that will have a big clinical impact, they need to find something that works for generalized social phobia, works at least as well as MAOIs, and does not have all the side effects, drug interactions, and dietary requirements...AND I would want to see long-term efficacy studies, that show reductions in avoidance behaviors.  After all, it is not the anxiety that ruins people's lives; the avoidance behavior is what causes all the problems.  

A drug that does all that would get my attention, and get me to call my stockbroker (if I had one, which I do not.)   So far, all they have shown is a reduction in anxiety levels in one particular kind of situation.  That is more of a curiosity that a clinical breakthrough.

No, the real reason that the DCS studies are interesting, is that they may provide some avenue for exploring the neurochemistry of social phobia.  Perhaps that could lead to  the development of a new class of molecular entities.