Dr. Boriskin explains that someone can have an addictive disorder without post-traumatic stress disorder – or PTSD without substance abuse issues – but it’s very common for the conditions to co-occur. In fact, he estimates that more than 80 percent of the military veterans he treats for PTSD also have a substance-abuse disorder.

“The timing of which comes first is irrelevant,” he says. “It’s imperative to come to terms with the addiction first, then start working with the PTSD issue.” He notes that both disorders are difficult to treat, but both respond to similar interventions.