U.S. government experts are seeking new ways to treat a flood of American troops returning from Iraq and Afghanistan with substance abuse problems compounded by conditions like post-traumatic stress disorder.

"This new combination of moderate traumatic brain injury along with post-traumatic stress disorder and the substance abuse has been very difficult to treat," Dr. Thomas Kosten, who heads a Department of Veterans Affairs effort to improve substance abuse treatment, said on Wednesday.

"We're seeing things that we, quite frankly, haven't seen before in terms of having to treat them," said Kosten, a psychiatry and neuroscience professor at Baylor College of Medicine in Texas.

National Institutes of Health, Pentagon, VA and academic experts met on Tuesday and Wednesday to consider recommendations on preventing and treating substance abuse among troops returning from Iraq and Afghanistan.

Dr. Nora Volkow, director of the NIH's National Institute on Drug Abuse, hoped for final recommendations in two months.

"Substance abuse disorders are much more prevalent among individuals that have been exposed to war environments, as are other psychiatric disorders. So the outcomes of these individuals, if not properly addressed, can be very poor," Volkow said in a telephone interview.

Many troops coming home from the wars binge-drink alcohol, Kosten said. About 3 percent are hooked on opiate painkillers. And overall, the returning troops smoke cigarettes at levels more than double that of the general population, he said.

A study by the RAND Corp. research organization estimates that about 18.5 percent of the U.S. troops sent to Iraq and Afghanistan show signs of either PTSD or depression, conditions linked closely with substance abuse.

PTSD can stem from wartime trauma such as being wounded or seeing others hurt or killed.

Symptoms range from irritability and outbursts of anger to sleep difficulties, trouble concentrating, extreme vigilance and an exaggerated startle response. People also can persistently relive the traumatic event.

Kosten urged a more uniform approach to treating them with their various problems.

"There needs to be much more following of a protocol, so to speak, and less of a free-for-all kind of treatment that's provided — and then monitoring the outcomes," Kosten said.

"I think if you went to 10 different places to get your post-traumatic stress disorder treated, you could get 10 different treatments, it feels like. That would be including the VA," Kosten said.