In their article, Southwick et al1 did not discuss the ramifications of the high rate (85%) of life-time alcohol dependence in their subjects. They concluded that posttraumatic stress disorder (PTSD) and panic disorder may "share a common neurobiological abnormality that is related to altered sensitivity of the noradrenergic system."1 However, the authors did not mention what impact alcohol dependence might have on panic disorder or on the noradrenergic system.
In a review of the relationship between alcohol problems and anxiety disorders, it was suggested that sumptoms of panic disorder often result from, rather than cause, problem drinking.2 Kushner et al2 speculated that the cumulative effects of alcohol withdrawal (autonomic nervous system hyperexcitability), toxic effects of long-term alcohol use, and negative alcohol-related consequences (social, legal, and interpersonal) may trigger symptoms of panic disorder. It has also been proposed that the chemical and cognitive changes from repeated alcohol withdrawals
Wiseman EJ. Alcohol Dependence May Be the Missing Link Between Posttraumatic Stress Disorder and Panic. Arch Gen Psychiatry. 1994;51(5):429-430. doi:10.1001/archpsyc.1994.03950050089013