Clinical trial NCT00206934: The Effects of Increased Central Serotonergic Activity on Information Processing
Official title: The Effects of Increased Central Serotonergic Activity on Psychophysiological Parameters of Human Information Processing
Study type: INTERVENTIONAL
Overall status: COMPLETED
Phase: NA
Conditions: Healthy Volunteers
Keywords: PPI
P50 suppression
P300
mismatch negativity
escitalopram
Lead sponsor: University of Copenhagen
Sponsor class: OTHER
Collaborators: name: Lundbeck Foundation
name: Glostrup University Hospital, Copenhagen
First posted: 2005-09-21
Enrollment: 40
Sex: MALE
Minimum age (years): 18
Maximum age (years): 35
Standard ages: ADULT
Accepts healthy volunteers: yes
Allocation: RANDOMIZED
Intervention model: SINGLE_GROUP
Primary purpose: DIAGNOSTIC

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.

Eligibility criteria: 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.

Primary outcomes:
measure: The PPI (Prepulse Inhibition of the Startle Response) task
timeFrame: Once, 3.5 hrs after intake of capsule
measure: The P50 Suppression task
timeFrame: Once, 3.5 hrs after intake of capsule
measure: The P300 ERP task
timeFrame: Once, 3.5 hrs after intake of capsule
measure: The mismatch negativity (MMN) task
timeFrame: Once, 3.5 hrs after intake of capsule
Secondary outcomes:
Other outcomes:
Locations:
city: Glostrup
country: Denmark
facility: Center for Neuropsychiatric Schizophrenia Research, University of Copenhagen, Psychiatric Center Glostrup
Study officials:
affiliation: Center for Neuropsychiatric Schizophrenia Research, University of Copenhagen, Psychaitric Center Glostrup, Ndr. Ringvej, DK-2600 Glostrup, Denmark
name: Birte Glenthoj, MD, DMSc.
role: STUDY_DIRECTOR
References: