Today's report is the first in a series of five reports.
Watch Brian Ross' exclusive investigation, "Coming Home: Soldiers and Drugs," Friday on "20/20" at 10 p.m. EDT
They were prepared for war. They were prepared to die for their country. But Fort Carson soldiers say they weren't prepared to come home and fight a different battle -- addiction to illegal drugs.
Many of this country's bravest men and women who volunteered to defend America in a time of war have come home wounded -- physically and mentally -- and are turning to illicit drugs as they adjust to normal life, according to soldiers, health experts and advocates.
"Lots of soldiers coming back from Iraq have been using drugs," said Spc. William Swenson, who was deployed to Iraq from Fort Carson. "Right when we got back, there were people using cocaine in the barracks; there were people smoking marijuana at strip clubs; one guy started shooting up," he said.
Fort Carson, just outside Colorado Springs, is home to 17,500 active duty personnel. Four thousand eight hundred service members are currently deployed in the "sand box," as soldiers call Iraq and Afghanistan.
ABC News spoke to more than a dozen soldiers who described widespread abuse of illegal drugs at Fort Carson by service members back from the war.
Spc. Alan Hartmann was a gunner on a Chinook helicopter flying missions from Kuwait into Iraq in 2003. He described the high of flying and the feeling that "nothing can touch you" as well as the terror of being shot at.
After sustaining a neck injury in Iraq, Hartmann returned to Fort Carson. Having regularly ferried the bodies of American soldiers killed in combat -- with the helicopter exhaust blowing warm air and the smell of death through the craft -- Hartmann said he had trouble sleeping. The nightmares were too bad, he said.
To help Hartmann deal with his physical and emotional pain, Army doctors prescribed painkillers and anti-depressants -- two typewritten pages' worth since he's been back. But Hartmann said he didn't like how the drugs made him feel, and instead he turned to self-medication with methamphetamines.
"The nightmares were killing me from being over there. The pain was so bad I didn't want to deal with it. Well, amphetamines is a real quick way to get rid of it," Hartmann said. "I was snorting it, and I was smoking it, and then I was hot railing it, and then I got to the point where I was actually injecting it in my arms," said Hartmann, who eventually checked himself into rehab and is now clean.
"[Soldiers are] coming back, drinking, fighting, putting $1,000 tabs down at a bar and drinking four to five hours, getting to the point where you don't give a crap about anything anymore [or] anybody, don't care if you live or die&the point where you do drugs," Hartmann said. "[Drugs] have been in Fort Carson like crazy."
Another former Fort Carson soldier, Michael Bailey, said he was discharged from the Army after testing positive for cocaine.
Bailey served two tours, one in Iraq and another in Kuwait. The stress of his deployment combined with marital problems overwhelmed Bailey who said he twice tried to commit suicide.
"The dose [of anti-depressants] I was on wasn't working, so I was trying an extra one and that wasn't working," Bailey said. "So I started drinking, and at one point I did cocaine."
Baily said he failed a drug test the very next day. Even though he was in the process of receiving mental health counseling from the Army, Bailey said he was discharged over his drug use. At the time of his interview with ABC News, Bailey was unemployed and still grappling with feelings of depression and anxiety.
And then there's combat engineer William Swenson who was injured on what was to be his final mission in Iraq when his vehicle drove over a 200-pound improvised explosive device. The blast injured Swenson's spine, and he developed syringomyelia -- a condition in which cysts form on the spinal cord.
Swenson said a laundry list of prescribed painkillers was ineffective so he turned to marijuana, the only substance that he said would numb his physical and emotional pain. Swenson failed a drug test after testing positive for marijuana as well as cocaine.
"I think a lot of people using drugs, soldiers mainly, coming back from Iraq, it's just to get an escape from&all those horrible things that came into their mind when they were over there," Swenson said.
Army Denies Growing Drug Abuse Problem
Fort Carson's leadership declined to discuss substance abuse issues with ABC News despite numerous interview requests. Fort Carson also said it could not comment on the individual cases of the soldiers we interviewed, citing privacy concerns.
In interviews with ABC News at the Pentagon, however, the U.S. Army strongly denied there was an increase in drug abuse among soldiers deployed to Iraq.
According to Dr. Ian McFarling, acting director of the Army Center for Substance Abuse Programs, less than one half of one percent of soldiers in Iraq have tested positive for illegal drugs.
"That's a testament to the kind of leadership we have is that they believe that that's not the place that they should be doing drugs," said Dr. McFarling.
But Dr. McFarling said that once soldiers return from Iraq, the positive rate for drug tests doubles to more than one percent. In addition, Dr. McFarling said five percent of soldiers back from Iraq seek help for substance abuse issues from clinical providers.
The U.S. Army does offer treatment for soldiers dealing with drug abuse, and Fort Carson has a busy Army Substance Abuse Program.
But some soldiers are forced off post because Fort Carson offers no inpatient services; others get treatment in the community to avoid the stigma associated with seeking help, soldiers and advocates said.
Since the Iraq war started in 2003, Colorado Springs hospitals and counseling services have seen a dramatic increase in active duty soldiers seeking treatment for substance abuse. Penrose-St. Francis Health Services went from treating no active duty soldiers for substance abuse before the war to between 30 and 40 now, said Phillip Ballard, the hospital's inpatient psychiatrist.
According to Ballard, "Now that we have larger numbers than the military facilities can treat&it falls upon the civilian community to treat those patients."
Veterans' advocacy groups charge that the problem of substance abuse is much greater than the Army wants to publicly acknowledge, and it's growing.
"I've met with veterans from coast to coast, and I will tell you that there is a catastrophe on the horizon," said Paul Sullivan, director of Veterans for Common Sense.
Three thousand fifty-seven veterans of the Iraq and Afghanistan wars were potentially diagnosed with a drug dependency from fiscal year 2005 through March 2007, according to figures provided to ABC News from the Veterans Health Administration. From 2002 through 2004, only a total of 277 veterans were diagnosed with drug dependency, the numbers show.
"The military right now can say whatever they want, but the truth on the ground is that the soldiers are in a lot of pain, emotional and physical pain, and they're turning to drugs in order to alleviate that," said Sullivan.