In reply
We appreciate Dr Wiseman's effort to highlight the possible neurobiological significance of substance abuse for patients with PTSD and panic disorder. Similar to the clinical reports on patients with panic disorder that she cited, we and others previously described cases in which acute alcohol or opiate withdrawal exacerbated PTSD symptoms in dually diagnosed patients.1,2The hypothesis that activation of noradrenergic systems might increase panic or PTSD symptoms was studied in a series of investigations using the α2-adrenergic antagonist, yohimbine. We found that this drug elicited panic attacks in some patients with panic disorder and PTSD, but not in healthy subjects or patients with other major psychiatric disorders including generalized anxiety disorder, major depression, and schizophrenia.3,4While it is likely that the cycle of alcohol consumption and withdrawal affects the course of panic disorder and PTSD, there is little evidence to support the hypothesis that subacute alcohol