Ben Cardin, a Maryland Democrat, has asked the Pentagon for info on how many troops in war zones have been prescribed antidepressants while they were deployed. Cardin sent a letter Tuesday to US Department of Defense Secretary Robert Gates expressing concern about how antidepressants are being administered troops in Iraq and Afghanistan.

Cardin wants to determine if the Defense Department is prescribing antidepressants appropriately and is concerned about any connection between the meds and suicide rates among troops. In October, for instance, 16 active-duty US soldiers killed themselves, bringing the total number of active-duty suicides in 2009 to 134. At this rate, the number of 2009 suicides will eclipse last year’s total of 140 – the highest yearly number of suicides in Army history. Cardin also notes the rate of active-duty suicides is greater than that of the US population, although he doesn’t question the “long-term efficacy” of the drugs.

Most soldier/vet suicides get blamed on PTSD. This overlooks a couple important things:

1. Depression and drinking problems are both more common than PTSD is, even among combat vets, and have a more robustly established and higher suicide risk.

2. As the story above notes, antidepressant use among younger people, especially if not monitored closely, is shown to carry a significant suicide risk.

Cardin’s effort is an attempt to address the second problem. This is a good example of how reflexive diagnoses, as PTSD has become for any combat veteran (and sometimes even prospective combat veterans — i.e., troops preparing to deploy), can do harm. They can lead you to ignore other possible causes of the symptoms on display.