Consistencies between recalled panic and lactate-induced panic.

This study investigated the frequency and severity of symptoms during naturally occurring panic attacks recollected as "usual" and during sodium lactate-induced attacks. Seventy-six male and 126 female patients with panic disorder or agoraphobics with panic attack (DSM-III criteria) underwent lactate infusion studies and were serially administered the Acute Panic Inventory (API). Fifty-nine percent of the subjects were rated by an attending psychiatrist to have experienced lactate-induced panic attacks. Patients were also asked to API symptom rate their "usual" panic attacks. For panic recollected as usual, the most frequently reported symptoms (> or = 75%) at the moderate to severe levels included: afraid in general, difficulty concentrating, difficulty performing a job, desire to flee, afraid of losing control, palpitations, feeling hot or cold or both, dyspnea, dizzy-lightheaded. During lactate infusion, 25 of 29 API symptoms increased significantly from prelactate to point of panic; however, particularly robust effect sizes were exhibited for the desire to flee, dyspnea, tingling, twitching/trembling and difficulty doing a job. Comparison of panic recollected as usual and lactate-induced panic showed that more than half of the symptoms did not differ after Bonferroni correction; however, the most notable were fear in general, dyspnea, chest pain/discomfort, difficulty swallowing, feeling weak, desire to flee, and feeling hot/cold or both. These data point to a very distinctive role during both recollected and lactate-induced panic attacks for fearfulness the desire to flee (by definition), and for dyspnea, difficulty performing a job and fear of losing control. During lactate-induced panic, dyspnea exhibited the most robust effect size of all physical symptoms.