Newswise — SILVER SPRING, MD, Nov. 4 2013 – Approximately 218,000 incident s of anxiety disorders were diagnosed among the active-component of the U.S. Armed Forces, a rate that steadily increased over a surveillance period in the past 13 years, according to a new study.

During the 13-year surveillance period there were 217,409 incident diagnoses of anxiety disorders among active component service members (Table 1), according to the study published in the Medical Surveillance Monthly Report, a peer-reviewed journal on illnesses and injuries affecting service members from the Armed Forces health Surveillance Center (AFHSC). The unadjusted incidence rate was 117.2 per 10,000 person-years (p-yrs).

“In the U.S. Armed Forces, mental disorders, of which anxiety disorders are a subset, are a leading cause of morbidity, disability, healthcare service utilization, lost duty time, and attrition from military service,” Army Colonel William Corr, the deputy director of AFHSC’s division of Epidemiology and Analysis. “Incidence rates of mental disorders diagnoses overall and anxiety disorders in particular have increased sharply among U.S. military members during the past 10 years.”

For the majority of incident cases (n=205,717, 94.6%), their first anxiety disorder-related diagnosis was a “non-specific anxiety disorder” (i.e., ICD-9-CM: 300.0, 300.00, or 300.09). Many of these individuals later received more specific anxiety-related diagnoses: generalized anxiety disorder (n=29,504, 14.3%); panic disorder without agoraphobia (n=16,789, 8.2%); specified phobic disorders (n=9,234, 4.5%); and obsessive-compulsive disorder (n=3,278, 1.6%) data not shown).

Of note, however, more than three-fourths (n=157,549, 76.6%) of those whose incident diagnoses were one of the “non-specific anxiety disorders” did not receive more specific anxiety-related diagnoses during subsequent medical encounters.The surveillance period was January 1, 2000 to December 31, 2012. The surveillance population included all U.S. members of the Army, Navy, Air Force, Marine Corps, and Coast Guard who served in the active component at any time during the surveillance period.

Of the three main categories of anxiety disorder, “anxiety states” accounted for the most cases (n=203,130) and the highest incidence rate (109.5 per 10,000 p-yrs) Table 1). Only 2.7 percent of all incident medical encounters for “anxiety states” were hospitalizations (Table 2). Members of the Army, recruits, enlisted members, and those in healthcare occupations had markedly higher rates of anxiety state diagnoses than their respective military counterparts. Also, females, service members in their twenties, and white, non-Hispanics, had relatively high rates of anxiety state diagnoses.

Phobic disorders accounted for 21,675 cases (overall rate: 11.7 per 10,000 p-yrs); 679 (3.1% of the total) incident medical encounters for “phobic disorders” were hospitalizations (Table 2). The highest subgroup-specific rates of phobic disorder diagnoses were among recruits (22.3 per 10,000 p-yrs), females (19.6 per 10,000 p-yrs), and healthcare workers (16.3 per 10,000 p-yrs). Rates of phobic disorder diagnoses were highest among females, service members under the age of 20, and white, non-Hispanics. Service members in the Air Force, recruits, junior enlisted service members, and those in healthcare occupations had higher rates of phobic disorder diagnoses than their respective military counterparts. Social phobia was the most frequently diagnosed phobic disorder (n=9,531; rate: 5.1 per 10,000 p-yrs).

Obsessive-compulsive disorder accounted for 8,370 cases and an overall rate of 4.5 per 10,000 p-yrs during the surveillance period (Table 1). Annual incidence rates sharply increased from 2003 to 2008 and then slowly declined to a relatively stable level which has persisted from 2010 to 2012 (Figure 2). The highest subgroup-specific rates of obsessive-compulsive disorder diagnoses were among females (8.4 per 10,000 p-yrs), recruits (7.6 per 10,000 p-yrs), and healthcare workers (7.3 per 10,000 p-yrs). Also, service members in the Army and enlisted members (particularly junior enlisted) had higher rates of obsessive-compulsive disorder diagnoses than their respective counterparts in military service.

During the 13-year surveillance period, an anxiety disorder was recorded as the primary (first-listed) diagnosis after 1,167,634 medical encounters of 219,972 service members (mean: 5.3 anxiety disorder-related medical encounters per affected individual) (Figure 3). Annual numbers of anxiety disorder-related medical encounters and numbers of individuals affected increased 704 percent and 502 percent, respectively, during the period.

Approximately one-third of all service members diagnosed with an anxiety disorder were also diagnosed with an adjustment disorder (34.3%) or a depressive disorder (33.5%) within one year before or after their case-defining anxiety disorder encounters (data not shown).

During the 13-year surveillance period, an anxiety disorder was recorded as the primary (first-listed) diagnosis after 1,167,634 medical encounters of 219,972 service members (mean: 5.3 anxiety disorder-related medical encounters per affected individual) (Figure 3). Annual numbers of anxiety disorder-related medical encounters and numbers of individuals affected increased 704 percent and 502 percent, respectively, during the period.

Approximately one-third of all service members diagnosed with an anxiety disorder were also diagnosed with an adjustment disorder (34.3%) or a depressive disorder (33.5%) within one year before or after their case-defining anxiety disorder encounters (data not shown).

As with other mental disorders, the physical and mental challenges associated with basic military (recruit) training, the cumulative health effects of continuous exposure of a military force to the stresses of prolonged war fighting, the increased attention to and availability of mental health services, and the decreasing stigma associated with mental healthcare seeking and mental disorder diagnoses have impacted recent trends of diagnoses of anxiety disorders, the study said.

Significant increases in resources to identify and treat mental disorders among service members and successes in reducing stigmatization for seeking care for anxiety symptoms likely contribute to such increases, the study said. To the extent that such initiatives continue, it is likely that rates of diagnoses of and healthcare burdens associated with treatment of anxiety disorders and other mental disorders will continue to increase.

Click here to read entire study. The MSMR is the flagship publication for the AFHSC, featuring articles on evidence-based estimates of the incidence, distribution, impact and trends of illness and injuries among U.S. military service members and associated populations.

Other articles in the October issue:•“Acute Gastrointestinal Infections, U.S. Armed Forces, 2002-2012”•"Update: Cold Weather Injuries Active and Reserve Components, U.S. Armed Forces, July 2008-June 2013”•“Surveillance Snapshot: Influenza Immunizations Among HealthCare Workers, Active Component, U.S. Armed Forces, August, 2002-April 2013”•“Deployment Related Conditions of Special Surveillance Interest”