The Corpus Callosum

I just finished reading a news release pertaining to a finding in
psychiatric genetics.  I was prepared to be irritated, but was
pleased instead.

href="http://www.med.umich.edu/opm/newspage/2006/ocd.htm">New
genetic findings add to understanding of obsessive-compulsive disorder
Kara Gavin
July 26, 2006

ANN ARBOR, MI – Obsessive-compulsive disorder tends to
run in families, causing members of several generations to experience
severe anxiety and disturbing thoughts that they ease by repeating
certain behaviors. In fact, close relatives of people with rel="tag"
href="http://www.med.umich.edu/1libr/wha/wha_obsessco_bha.htm"
class="bodylink">OCD are up to nine times more
likely to develop OCD themselves.


The article goes on to explain that there is an association between OCD
patients and a glutamate transporter gene, SLC1A1.
 They provide a (very) brief explanation of what glutamate
does, and a brief overview of how the discovery came about.
 They also add a bit about anticipated future research.
 Those additional bits of information put the current studies
in context.

Most importantly, though, the article does not overemphasize the
importance of the current findings:

While the new findings are exciting because they
strengthen the evidence for glutamate’s role in OCD
vulnerability, the researchers caution that more work needs to be done
before their discovery has any impact on OCD treatment.

Of course, from a clinical standpoint, the reason the research is
important is that it could eventually lead to some kind of improved
treatment, or at least a different treatment option.  But that
is so far off, that it would be premature to suggest that as a
possibility.  Rather, it is more appropriate to focus on the
excitement of reaching a milestone, of sorts.   There have
been dozens of news reports about genetic findings in various
psychiatric conditions, but I don’t think any of them has led to any
kind of treatment.

One reason that it is important for the public to hear about studies on
psychiatric genetics is that it helps to reinforce the concept of a
biological basis for many psychiatric conditions.  However, it
is equally important to not overemphasize the role of genetic factors.
 There probably are not any psychiatric conditions that are
caused by a single gene or single mutation.  If it were that
simple, psychiatrists would leave it to internists to treat.

Again, putting the study in context, they note:

In a commentary published in the same issue of the
journal, two Yale University researchers call the new findings
promising, and call for additional research. “These data add
to a growing body of work that suggest that SLC1A1 is perhaps a primary
candidate gene for OCD,” they write.

It is important for the public to appreciate the fact, that very few
studies mean very much on their own.  Rather, they are
important because they contribute to a larger body of knowledge.

The new findings are especially important not only
because of the simultaneous discoveries reported in the papers, but
also because of previous studies that show a functional link between
glutamate and OCD. Brain imaging and spinal fluid studies have shown
differences in the glutamate system between OCD patients and healthy
volunteers, including in areas of the brain where the EAAC1 protein is
most common.

It is especially nice when multiple lines of evidence converge.
 It gives scientists that warm, fuzzy feeling all over.

Another nice feature of the news release is that they provide the
 reference for the papers they cite in text: Dickel et al, and
Arnold et al, Archives
of General Psychiatry
,
Vol 63, July 2006. pp
778-785 and pp 769-776. Commentary by Leckman and Kim, pp. 717-719.
 I’ve had the experience before, of reading these kinds of
press releases, but being unable to find the paper they were talking
about.  Not only is that frustrating, it limits the usefulness
of the press release.