Enlarge By Chris Hondros, Getty Images Iraq war veteran Robert Wake, who was diagnosed with post-traumatic stress disorder, talks to physical therapist Nicole Bormann before a session in the VA Medical Center on Aug. 10, 2009, in St Louis, Mo. Wake served in Iraq from 2003-2004 and was seriously wounded by a mortar shell in Najaf. HOSPITALIZATIONS HOSPITALIZATIONS WASHINGTON  Mental health disorders caused more hospitalizations among U.S. troops in 2009 than any other reason, according to medical data released recently by the Pentagon. This historic high reflects the growing toll of nearly nine years of war. Last year was the first in which hospitalizations for mental disorders outpaced those for injuries or pregnancies in the 15 years of tracking by the Pentagon's Medical Surveillance Monthly report. Hospitalizations for mental disorders have increased significantly among troops since 2005, said Lt. Gen. Eric Schoomaker, surgeon general for the Army. "War is difficult. It takes a toll," he said. Mental health treatment expenses are helping drive up the overall cost of military health care, USA TODAY reported last month. Last week, Defense Secretary Robert Gates said in a speech that "health care costs are eating the Defense Department alive." Schoomaker said the Army's increased attention to mental health issues is another reason for the rise in hospital admittances. In 2009, there were 17,538 hospitalizations for mental health issues throughout the military, the study shows. That compares with 17,354 for pregnancy and childbirth reasons, and 11,156 for injuries and battle wounds. MILITARY APPRECIATION MONTH: How to celebrate PTSD: One-man army fights war's stresses CAREGIVING: Families of severely injured veterans feel strain FAITH: Ministries try to help veterans with PTSD ART: Stressed troops take cues from ancient plays In 2007, there were 18,201 pregnancy and childbirth hospitalizations, 13,703 for mental health and 12,531 for injury and battle wounds, statistics show. In 2005, mental health was the third leading cause with 11,335. Mental health care accounted for almost 40% of all days spent in hospitals by servicemembers last year, the report said. Of those hospitalizations, 5% lasted longer than 33 days. For most other conditions, fewer than 5% of hospitalizations exceeded 12 days, the report said. Psychological issues such as post-traumatic stress disorder exact a toll in lost manpower, the study said. Four mental health issues — depression, substance abuse, anxiety and adjustment problems such as PTSD — cost the Pentagon 488 years of lost duty in 2009. That's "the equivalent of 488 soldiers spending an entire year in the hospital for mental disorders," said Army Col. Robert DeFraites, director of the office which produced the study. The Pentagon is learning that mental health issues can take months or years to develop, he said. "Mental disorders are a trailing indicator of health issues to a prolonged period of war fighting, and these figures reflect that," DeFraites said. "Our troops are facing multiple deployments and experiencing psychological stress due to prolonged exposure to combat," said Brig. Gen. Loree Sutton, director of the Defense Centers of Excellence for Psychological Health and Traumatic Brain Injury. The Army, which has 138,000 soldiers in Iraq and Afghanistan, had 10,222 mental health hospitalizations last year. They accounted for almost 19% of all Army hospitalizations. Ten percent of Marine hospitalizations were for mental health reasons, while they were about 8% for the Navy and 7% for the Air Force. The costs of treating mental disorders will only grow, said Christine Eibner, an economist with the RAND Corp. A night in a military hospital cost $3,000 in 2009, said Austin Camacho, a spokesman for the military health care program. When the Pentagon pays for private hospital care, the average daily cost is about $1,300, he said. Guidelines: You share in the USA TODAY community, so please keep your comments smart and civil. Don't attack other readers personally, and keep your language decent. Use the "Report Abuse" button to make a difference. You share in the USA TODAY community, so please keep your comments smart and civil. Don't attack other readers personally, and keep your language decent. Use the "Report Abuse" button to make a difference. Read more