Purpose. Since clinical practice suggests that panic disorder may not be a
homogeneous condition, a study was carried out to test the possible existen
ce of different groups or subgroups of panic patients. Subjects and methods
. Thirty-two panic patients (DSM-III-R) underwent lactate challenge in our
laboratory and were assessed for heart rate, blood pressure. sweating and A
cute Panic Inventory. Results. During the lactate challenge, patients compl
aining mainly of 'cardiorespiratory' symptoms (N = 12) showed tachycardia a
nd localized sweating. Conversely, patients complaining mainly of 'pseudone
urological' symptoms (N = 16) showed bradycardia and generalized sweating.
In both groups, Acute Panic Inventory scores were significantly higher duri
ng than before the panic attack, but the distribution of the scores was mar
kedly different. Discussion and Conclusion. The results suggest that panic
disorder may be a heterogeneous condition. Implications of these results to
other phobic disorders, to Klein's false suffocation alarm theory and to t
he 'extended amygdala model' are discussed. (C) 2001 Editions scientifiques
et medicales Elsevier SAS.