Preventive Medicine is the medical specialty devoted to population health and the prevention of disease. As such, the training of Preventive Medicine physicians not only includes clinical training in the treatment and prevention of traditional domestic communicable diseases, as well as tropical and travel medicine—but also academic training in such areas as biostatistics, epidemiology, and health policy analysis. After completing internship, as part of my residency, I learned these skills by earning a masters degree in public health (MPH) at the Johns Hopkins Bloomberg School of Public Health, in Baltimore, Maryland. The next year, while still in training, I put this education to good use by developing a program to reduce redundant immunizations of Army recruits. At the time, in a somewhat misguided attempt at efficiency, the Army had been giving every recruit heading off to war the same four or five vaccines, regardless of whether they had previously received these. The program I proposed, which would implement a system for testing the blood of new recruits for immunity so as to permit customizing the vaccines they received, was clearly the right thing to do medically—but I knew if it slowed down the processing of new recruits, the Army would never permit it. Thanks to my training, I was able to demonstrate that the program could work within the tight schedules of the recruit centers. Additionally, it would save money, as the costs of expensive vaccines were used to fund the much less expensive blood testing and the staff needed to organize the effort. Within a few months of presenting my proposal to senior Preventive Medicine physicians, the Army Surgeon General gave formal approval to implement the program, and I received a letter of commendation from my commanding General.

At Johns Hopkins where I trained in public health [1], the Bloomberg School’s motto had been “Protecting Health, Saving Lives, Millions at a Time.” It pleased me to know that within a few short years, as the number of Army recruits increased by tens of thousands year over year, my program would protect the health and improve the lives—at least in some small way—of at least one million new soldiers [2]. Impressed early in my career by the power to make a difference within the seemingly impenetrable Army medical bureaucracy, I looked forward to my first assignment at the Army Medical Surveillance Activity (AMSA) , in Washington, DC, where I hoped to continue to make a difference working in military public health.

It was there at AMSA, in the months before my deployment, that I supervised a team of civilian analysts who poured over military health data, conducting analyses, identifying patterns of disease, and informing recommendations to military leaders on how to better protect the health of the force [3]. The Army Medical Department’s motto was, “To Conserve Fighting Strength.” We considered it a critical component of living up to this motto to provide our leaders information on what diseases the fighting strength was being affected by, and how these could be better prevented.

Throughout the history of the US Army, the primary threats to the health of fighting forces had been from infectious diseases and injuries [4], and the work of AMSA had been primarily in these areas. The majority of my work consisted of overseeing injury reports, and conducting analyses on acute respiratory disease and infectious diseases such as malaria, influenza, HIV, hepatitis [5], and sexually transmitted infections [6].

As with my earlier work on vaccine policy, prevention strategies in these areas almost immediately improved the health of the force, and ensured that even more healthy soldiers were available for the war effort. This work was almost perfectly aligned with the goals of military leadership, so our efforts were strongly supported and well funded. With the benefit of supplemental wartime funding, AMSA soon moved into new office space just outside the Washington, DC beltway, to merge formally with an organization known as the Global Emerging Infections Surveillance and Response System (GEIS) to become the Armed Forces Health Surveillance Center, with a focus particularly on infectious diseases [7].

Although my interests at the time had been squarely in the area of infectious diseases, in the months prior to my deployment, through my work I had become increasingly aware of the growing toll of mental illnesses on our forces. In a 2006 report, our analysts had identified a notable increase in the rate of clinical encounters for mental health disorders—up 12 % since the start of the wars—higher than in any other category of disease [8]. My analysts had also reported noting a high prevalence of psychotropic drug use in the sample pharmacy datasets they had begun examining. Yet when I recommended that our center devote more attention to the study of mental health problems, such as had previously been done [9], my proposal was initially met with disinterest. Much of the public health community appeared to feel that work of this nature was not the proper domain of epidemiologists and Preventive Medicine physicians, but rather of psychiatrists, a small group of whom were already involved in research in these areas [10].

It was around this time that I received my temporary reassignment orders. Increasingly intrigued by the idea of mental disorders as a potential military public health problem, it was with this perspective that I returned to Ft. Bragg to join the 82nd Airborne Division for deployment. Within days of my arrival, I would quickly realize how relevant this perspective would be to my deployment, and how my public health colleagues’ perceptions of the problem posed by mental disorders lagged the realities I observed within front-line combat units.

This first became clear as we assembled at the airfield, preparing to board our flights for deployment. There, we were told by medics of the 82nd Airborne Division—much to my surprise—to reach into a large garbage bag and grab a box of medicine that had been collected in bulk from the local military pharmacy. The box contained mefloquine , which we were to begin taking to prevent malaria while overseas.

From my training in travel medicine, I was very aware that mefloquine could not be safely prescribed to those with certain pre-existing mental health problems [11]. How did whoever had prescribed the drug know that everyone deploying with me was free of contraindicating mental health conditions? The prior AMSA analysis had suggested that across the Army as a whole, these contraindicating mental health problems were relatively common. I convinced myself that the 82nd Airborne Division was an elite unit, with rigid eligibility criteria, and presumably the soldiers deploying with me had been carefully screened prior to deployment .

However, once in Afghanistan, over the long hours that would follow, I would gradually learn through personal discussions with a number of my fellow unit members that many were in fact taking psychotropic drugs that had been prescribed by military healthcare providers in the days prior to their deployment. As the weeks progressed, these colleagues—many still improperly taking mefloquine [12]—would confess their continued struggles with various psychiatric symptoms, some of which had been diagnosed, but some of which were being empirically treated with these drugs without documented indication.

Intrigued by what I now perceived as a potentially very serious public health problem, I undertook a formal analysis under the authority of the 82nd Airborne Division Surgeon. Reaching back to my AMSA colleagues outside of Washington, DC, I requested data on prescription drug utilization as well as the medical and psychiatric histories of our force. Working on a ruggedized laptop AMSA had provided me for my deployment, I spent my evenings in the relative comfort of our dusty Soviet-era office, combing through the data.

The results of my analysis were surprising: Of the force that had deployed to Afghanistan under our command, a significant number—slightly fewer than 5 %—had received a formal mental health diagnosis in the year prior. More surprisingly, as my anecdotal experience had suggested, approximately 7 % had received a psychotropic drug in the 6 months prior to deployment [13].

In one of our infantry battalions, on the front lines of a particularly grueling fight, these figures were even higher: 15 % had received a mental health diagnosis, and 7.7 % had received a psychotropic drug, within the year prior [14]. Among our female service members, these rates were even higher—approximately double that of the deployed force as a whole [13]. Examining specific diagnoses, my data indicated we had even deployed personnel with recently diagnosed psychotic and bipolar disorders [15].