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The Effects of Increased Central Serotonergic Activity on Information Processing

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

Status
Completed
Phases
NA
Study type
Interventional
Source
ClinicalTrials.gov
Registry ID
NCT00206934
Enrollment
40
Registered
2005-09-21
Start date
2005-03-31
Completion date
2006-03-31
Last updated
2011-09-19

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Healthy Volunteers

Keywords

PPI, P50 suppression, P300, mismatch negativity, escitalopram

Brief 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.

Detailed 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.

Interventions

DRUGEscitalopram

Either 10 mg of escitalopram or placebo will be administered to a group of healthy volunteers

DRUGescitaolpram

Either 15 mg of escitalopram or placebo will be administered to healthy volunteers

Sponsors

Lundbeck Foundation
CollaboratorOTHER
Glostrup University Hospital, Copenhagen
CollaboratorOTHER
University of Copenhagen
Lead SponsorOTHER

Study design

Allocation
RANDOMIZED
Intervention model
SINGLE_GROUP
Primary purpose
DIAGNOSTIC
Masking
TRIPLE (Subject, Investigator, Outcomes Assessor)

Eligibility

Sex/Gender
MALE
Age
18 Years to 35 Years
Healthy volunteers
Yes

Inclusion criteria

* Male subjects * Good Physical and Mental Health meeting criteria never mentally ill, which will be evaluated with a medical history checklist, ECG * Non smokers

Exclusion criteria

* Current use of any medication * Any subject who has received any investigational medication within 30 days prior to the start of this study * History of neurologic illness * History of psychiatric illness in first-degree relatives, evaluated with DSM-IV criteria * History of alcohol and drug abuse. Positive urine screening for amphetamine, cocaine, cannabis, or esctacy.

Design outcomes

Primary

MeasureTime frame
The PPI (Prepulse Inhibition of the Startle Response) taskOnce, 3.5 hrs after intake of capsule
The P50 Suppression taskOnce, 3.5 hrs after intake of capsule
The P300 ERP taskOnce, 3.5 hrs after intake of capsule
The mismatch negativity (MMN) taskOnce, 3.5 hrs after intake of capsule

Countries

Denmark

Outcome results

None listed

Source: ClinicalTrials.gov · Data processed: Feb 4, 2026