text:  and psychotherapy in one arm as they did. And in the other arm, they do the best available treatment for PTSD. Let's say you get psychotherapy, maybe you get some anxiolytics adjacent to help with some of the anxiety, and then you'd have to take care for what we call threats to internal validity. So you want to make sure that both treatment arms have the same amount of psychotherapy or have the same amount of contact with the clinician. And so if this is given,