Tens of thousands of American combat veterans returning home from Iraq and Afghanistan with undiagnosed brain injuries often were "thrown into a canyon" -- falling deeper into despair and sometimes flirting with suicide or addiction -- before trying to get help, according to a Johns Hopkins University study.

Written by Rachel P. Chase, Shannon A. McMahon and Peter J. Winch, researchers at the Baltimore university's Department of International Health, the study published in the December issue of Social Science and Medicine builds on previous work at Johns Hopkins. That work uncovered tens of thousands of undiagnosed and untreated brain injuries stemming from improvised explosive devices, or IEDs, the signature wound of America's 21st-century wars.

Innovations in body and vehicular armor saved the lives of troops who likely would have died of blast injuries in past wars, but survivors often had higher risk of memory loss, cognitive struggles, mood disorders, migraine headaches, addiction, insomnia and suicide.

The Johns Hopkins researchers conducted 38 in-depth interviews in 2013 and 2014 with Army combat veterans and their family members, and a model emerged: Veterans too often played down their wounds but became detached from friends and family. Many denied their downward spiral until a "wake-up call" forced them to seek help from Pentagon and Department of Veterans Affairs programs.

Aid could be difficult to obtain, however, without documentation that other soldiers obtained after 2007 because of better battlefield and post-deployment screening protocols.

"When veterans came to me before the study, there was so much uncertainty. They told me that they thought that they 'were alone' when they came home, but these actually were shared experiences. Their symptoms were very similar, so a picture of their lives post-blast exposure needed to be modeled," said Chase, who has a doctorate in international health from Johns Hopkins.

Veterans with the best outcomes typically had spouses who prodded them to get help or lived near a respected clinic that specialized in brain injury care or one that boasted an exceptionally good medical provider, "even within a reportedly low-functioning facility," researchers found.

The study found that veterans exposed to another bomb blast after 2010 -- when the military increased its efforts to diagnose and treat every brain injury from war or training -- often had better outcomes than those who were not wounded again.

Chase credited such post-2010 help to an evolving "social dynamic" within the military. Commanders now make sure troops get screened for potential concussions and are more likely to keep them out of training or off the battlefield until doctors clear them, she said.

The bigger problem is the "no, not, never code" that GIs adopt to deny exposure to blasts because they don't want to abandon their buddies in the fight and the bureaucratic red tape that continues to ensnare combat veterans who often display symptoms that could apply not just to traumatic brain injury, or TBI, but other invisible wounds of war, such as post-traumatic stress disorder, known as PTSD, according to Chase.

"One of the vets in the study told us what it was like," she said. "You go to one clinic, and they tell you, 'Oh, that's TBI.' Then you go to another clinic, and they say, 'No, that's PTSD.' Back and forth and you're still untreated."

A more detailed exploration of the study's findings is slated for 2016 in Military Medicine, the flagship journal for health care providers serving the Defense Department, the VA and the U.S. Public Health Service.

"For health providers, our study gives you a way to talk about the problem with the family, to show them that this isn't unusual and that there is hope for the veterans," Chase said.