Effects of serotonergic and noradrenergic antidepressants on auditory startle response in patients with major depression.
BACKGROUND
Amplitude, habituation and prepulse inhibition (PPI) of the acoustic startle response (ASR) in rodents and humans are sensitive to psychotropic drugs. Studies with rodents suggest that an increase or decrease in serotonin level in the brain alters several modalities of the ASR. So far, little is known about serotonergic and noradrenergic startle modulation in humans.


OBJECTIVE
This study was designed to investigate the effects of the selective serotonin uptake inhibitor sertraline versus the selective noradrenalin uptake inhibitor reboxetine on magnitude, habituation and PPI of ASR in patients with major depression.


METHODS
We studied ASR in 23 patients with the diagnosis of major depression according to DSM-IV who were randomly treated either with sertraline or with reboxetine. Initially, ASR assessment was carried out when patients were drug-free for at least 2 weeks and again after 14 days of treatment.


RESULTS
The habituation of ASR was strongly attenuated by sertraline and not significantly altered by reboxetine. None of the substances altered the startle reactivity. In addition, PPI was not altered by sertraline, but reboxetine tended to decrease PPI. The startle reactivity at baseline was correlated with improvement of depressive symptoms at the end of the study.


CONCLUSIONS
These results provide the first evidence for different effects of noradrenergic and serotonergic antidepressants on the startle response in depressed patients.
Quednow
Boris B
BB
Department of Psychiatry, University of Bonn, Sigmund-Freud-Strasse 25, 53105 Bonn, Germany. boris.quednow@ukb.uni-bonn.de
Kühn
Kai-Uwe
KU
Stelzenmuelle
Richard
R
Hoenig
Klaus
K
Maier
Wolfgang
W
Wagner
Michael
M
D000161:Acoustic Stimulation; D018759:Adrenergic Uptake Inhibitors / Q000494:pharmacology* / Q000627:therapeutic use; D000328:Adult; D018687:Antidepressive Agents, Second-Generation / Q000494:pharmacology* / Q000627:therapeutic use; D003865:Major Depressive Disorder / Q000188:drug therapy / Q000523:psychology*; D004566:Electrodes; D005260:Female; D006185:Habituation, Psychophysiologic / Q000187:drug effects; D006801:Humans; D008297:Male; D008875:Middle Aged; D009025:Morpholines / Q000494:pharmacology / Q000627:therapeutic use; D011569:Psychiatric Status Rating Scales; D000077593:Reboxetine; D013216:Reflex, Startle / Q000187:drug effects*; D017367:Selective Serotonin Reuptake Inhibitors / Q000494:pharmacology* / Q000627:therapeutic use; D020280:Sertraline / Q000494:pharmacology / Q000627:therapeutic use
D018759:Adrenergic Uptake Inhibitors; D018687:Antidepressive Agents, Second-Generation; D009025:Morpholines; D000077593:Reboxetine; D017367:Selective Serotonin Reuptake Inhibitors; D020280:Sertraline