Does trait anxiety influence effects of oxytocin on eye-blink startle reactivity? A randomized, double-blind, placebo-controlled crossover study

What Was Tested

This randomized controlled trial paper looks at Oxytocin.

However, effects of oxytocin on startle reactivity, a well-validated measure of defense system activation related to fear and anxiety, have been inconsistent.

Here the researchers investigated the influence of oxytocin on startle reactivity with particular focus on the role of trait anxiety.

Who Took Part

PubMed indexes the participants as teenagers, young adults, adults and middle-aged adults, men only.

Forty-four healthy male participants attended two experimental sessions.

Participants were assigned to groups of high vs. low trait anxiety based on their scores on the trait form of the Spielberger State-Trait Anxiety Inventory (STAI).

How the Study Was Run

In design terms this was a randomized, double-blind, placebo-controlled and crossover study.

Because people in this Oxytocin study were split into groups at random, differences between the groups are less likely to reflect who happened to join each one.

Neither the participants nor the staff measuring them knew who was on Oxytocin, so expectations could not easily colour the readings.

A placebo (an inactive look-alike) gave the Oxytocin group a baseline to be compared against.

In the crossover set-up each of the participants took both Oxytocin and the comparison in turn, acting as their own control.

Startle probes were presented in combination with pictures of social and non-social content.

Eye-blink startle magnitude was measured by electromyography over the musculus orbicularis oculi in response to 95 dB noise bursts.

What Was Measured

However, effects of oxytocin on startle reactivity, a well-validated measure of defense system activation related to fear and anxiety, have been inconsistent.

The subject headings attached to it are Anxiety, Blinking, Oxytocin, Personality and Reflex, Startle.

What This Means in Plain Language

The paper is a randomized, double-blind and placebo-controlled study of Oxytocin.

Results are reported in around 4 sentences of the abstract; we leave them to the paper itself rather than summarise them.

The publication is from 2018 (PloS one), a journal based in United States.

More context: the Oxytocin compound page, all human trials.