Soldiers listen as U.S. Secretary of Defense Ash Carter (not pictured) holds a question-and-answer session with U.S. military personnel at Kandahar Airfield in Kandahar February 22, 2015. (Jonathan Ernst/Reuters)

Peter W. Chiarelli is a retired U.S. Army general.

The high-grossing film “American Sniper ” was nominated for an Academy Award for best picture, but it deserves higher honors for highlighting one of the greatest causes of casualties in our recent wars: post-traumatic stress (PTS).

The story of Iraq war veteran Chris Kyle, who was killed by a Marine veteran suffering from the effects of PTS and other mental-health problems, makes a powerful case that PTS needs to be a higher national priority. (You’ll note that I don’t include the word “disorder” at the end of PTS; the longer PTSD label actually discourages some service members from seeking treatment.) Since “American Sniper” debuted, Veterans Affairs and Defense Department leaders have been highlighting their programs for helping veterans diagnosed with PTS. But are those programs working?

In too many cases, the answer is no. Our PTS diagnostics remain crude, and no drugs have been approved specifically for treating the condition. Complicating matters, because of genetic and other differences among individuals, patients react differently to varying drugs and dosages. Finding the right mix can be a frustrating saga of trial and error. The wrong drug or dose can, if not caught in time, become a factor in other serious mental-health and behavioral issues, even including suicide.

It only makes sense that once Defense Department doctors identify an effective treatment for a service member, that same treatment should be available when the service member leaves active duty and moves to VA for care. More often than not, however, it is not.

The disconnect occurs because Defense has an all-inclusive drug formulary that allows clinicians to prescribe almost any medication approved by the Food and Drug Administration, while VA has a very limited formulary, primarily to control costs. Medically discharged service members who are given a 90-day supply of PTS prescriptions eventually must report to their VA medical facility for refills, where they are often denied — not for medical reasons but because the medications they rely on are not on VA’s approved list.

This is not a case of one prescriber issuing Bayer aspirin while another uses Saint Joseph. Service members whose symptoms are being controlled by specific anti-depressant, anti-anxiety or anti-psychotic drugs, as well as pain and sleep medications, are forced to give them up and search for a replacement — often a painful and dangerous process — simply because Congress has failed to require Defense and VA to harmonize their drug formularies.

Let me be clear: The problem is not that doctors within the two systems disagree over which drugs should be part of their formularies. Their hands are tied. They must operate within the rules set out by Congress.

Rather than repeating the laborious process of finding another drug that works, many veterans have told me they sought out private providers to fill their prescriptions, usually paying for their medications out of pocket. Imagine how they feel about VA when their first experience with the agency is a doctor telling them they cannot fill a prescription that has relieved their PTS symptoms for months or even years. In some cases, the veteran is not even given enough of the recommended drug to safely discontinue its use.

I have testified about this serious discrepancy, most recently as a member on the Military Compensation and Retirement Modernization Commission, and have discussed it privately with members of Congress. A few have said they will try to address the problem, but most have declined, citing the added cost to VA of a fuller formulary and the time the Government Accountability Office would require to determine the budgetary impact of such a change. Shouldn’t the long-term cost, danger and social impact of denying vital medications to veterans provide a sufficiently compelling reason for Congress to act?

The obvious solution is to include the same medications in both formularies. If this is not possible, Defense Department doctors should exhaust all the options available on VA formulary first before considering any drugs not covered by VA. If neither of these options can be adopted, Defense doctors should at least warn service members that their current prescriptions will be unavailable in the VA system.

This problem needs to be fixed immediately. A directive released by VA in late January seeking to address the problem without correcting the misaligned formularies contains too many loopholes and is totally inadequate. We need a solution, and not a patch. Chris Kyle’s death underlines the urgency of providing effective treatments for PTS. We can start by getting the Defense and Veterans Affairs departments on the same page.