Impact of loudness dependency of auditory evoked potentials on the panic response to CCK-4.
BACKGROUND
Experimental panic induction with cholecystokinin-tetrapeptide (CCK-4) has been established as a model to study the pathophysiology of panic disorder. In line with the serotonin (5-HT)-hypothesis of panic disorder it has been suggested that the panicogenic effects of CCK-4 are mediated in part through the 5-HT system. The analysis of the loudness dependency of the auditory evoked potentials (LDAEP) is a valid non-invasive indicator of central serotonergic activity.


METHODS
We investigated the correlation between LDAEP and behavioral, cardiovascular and neuroendocrine panic responses to CCK-4in 77 healthy volunteers and explored whether differences in LDAEP paralleled subjective panic severity. Behavioral panic responses were measured with the panic symptom scale (PSS). Heart rate and ACTH/cortisol plasma concentrations were assessed concomitantly.


RESULTS
LDAEP did not differ between panickers and nonpanickers. Furthermore, LDAEP did not correlate with the behavioral panic response. However, a significant positive correlation between LDAEP and CCK-4 induced HPA-axis activation, which was uniform in panickers and nonpanickers, could be detected.


CONCLUSIONS
The psychological effects of CCK-4 rather are mediated by neurotransmitters others than the endogenous 5-HT system. However, the extent of the neuroendocrine activation related to the CCK-4 panic provocation was correlated with the LDAEP, thereby suggesting that central 5-HT mechanisms are involved in the HPA-axis activation during this challenge paradigm.
Department of Psychiatry and Psychotherapy, Ludwig-Maximilian-University, Nussbaumstrasse 7, 80336 Munich, Germany. Daniela.Eser@med.uni-muenchen.de
Daniela
D
Eser
Gregor
G
Leicht
Thomas
T
Baghai
Oliver
O
Pogarell
Cornelius
C
Schüle
Susanne
S
Karch
Caroline
C
Nothdurfter
Rainer
R
Rupprecht
Christoph
C
Mulert
D000161:Acoustic Stimulation / Q000379:methods; D000324:Adrenocorticotropic Hormone / Q000096:biosynthesis / Q000097:blood*; D000328:Adult; D004569:Electroencephalography; D005072:Evoked Potentials, Auditory / Q000187:drug effects; D006339:Heart Rate / Q000187:drug effects; D006801:Humans; D006854:Hydrocortisone / Q000096:biosynthesis / Q000097:blood*; D007030:Hypothalamo-Hypophyseal System / Q000187:drug effects / Q000503:physiopathology; D008144:Loudness Perception / Q000187:drug effects; D008297:Male; D010200:Panic / Q000502:physiology*; D010913:Pituitary-Adrenal System / Q000187:drug effects / Q000503:physiopathology; D011863:Radioimmunoassay; D012720:Severity of Illness Index; D013223:Statistics as Topic; D013758:Tetragastrin / Q000008:administration & dosage / Q000633:toxicity*
D013758:Tetragastrin; D000324:Adrenocorticotropic Hormone; D006854:Hydrocortisone