The Effects of Increased Central Serotonergic Activity on Information Processing

Healthy Volunteers Clinical Trial

Official title: The Effects of Increased Central Serotonergic Activity on Psychophysiological Parameters of Human Information Processing

Status Completed

Clinical Trial Summary

It is of great clinical relevance to know if selective serotonin re-uptake inhibitors affect information processing. Our hypothesis was that aspects of information processing would be disturbed whereas others would improve.

Clinical Trial Description

Numerous studies point to an increased serotoninergic activity in schizophrenia. Additionally, patients with schizophrenia often show reduced filtering of sensory information, which is reflected in reduced P50 suppression and reduced prepulse inhibition of the startle refex (PPI). Currently, the reports in literature on the effects of serotonergic agonists on sensory gating in humans are inconclusive. In an initial study performed in our laboratory, however, we found reduced P50 suppression following administration of imipramine (a combined serotonin- and noradrenalin reuptake inhibitor) to healthy volunteers. This result provides evidence for the involvement of either serotonergic, noradrenergic, or a combination of both pathways in sensory gating. In numerous animal studies however, sensory gating is reduced by agonists of 5-HT, which suggests a serotonergic, rather than a noradrenergic, involvement in sensory gating. Therefore, in a follow-up study, the effects of a selective serotonin reuptake inhibitor (escitalopram) will be investigated on sensory gating parameters of healthy volunteers. To further extend the data of our initial study, the subjects will additionally be tested for two more psychophysiological parameters of attention that are usually found to be disturbed in patients with schizophrenia, i.e. mismatch negativity and selective attention. The design will be a double blind, placebo controlled experiment, in which a single dose of escitalopram or placebo will be given to healthy, non-smoking male volunteers on two occasions, separated by at least a week, after which the subjects will be tested in the psychophysiological test battery. ;

Study Design

Allocation: Randomized, Endpoint Classification: Pharmacodynamics Study, Intervention Model: Single Group Assignment, Masking: Double Blind (Subject, Investigator, Outcomes Assessor), Primary Purpose: Diagnostic

Related Conditions & MeSH terms

• Healthy Volunteers

• NCT number: NCT00206934
• Study type: Interventional
• Source: University of Copenhagen
• Status: Completed
• Phase: N/A
• Start date: March 2005
• Completion date: March 2006