Oxytocin as Adjunctive Treatment of Schizophrenia

Status

Completed

Phase

Phase 2

Enrollment

39 participants (actual)

Sponsor

Emory University · Other

Design

Randomized · Double masking

Countries

1 country

United States

Start

Mar 2013

Primary completion

15 Mar 2017

Completion

15 Mar 2017

First posted

2 Apr 2012 (estimated)

Last update posted

4 Sept 2019

Conditions

Schizophrenia

The focus of the current project is to advance our understanding of the effects of oxytocin (OT) on components of social cognition in schizophrenia (SCZ). Despite the rapid increase in our understanding of the role of OT in rodent models of social behavior and an explosion of interest in the prosocial effects of OT in healthy controls, little work has been done to dissect the potential effects of OT on SCZ subjects with social deficits. Social deficits are a crucial aspect of the functional impairments that limit the rehabilitation of patients with SCZ. In particular, SCZ patients with enduring negative symptoms (deficit syndrome, Kirkpatrick et al. 1989) have prominent social deficits as a core feature of this subtype of the illness. Our currently available medications do very little to improve these social deficits. Hence it is of utmost public health importance to address the knowledge gap regarding the potential of OT to improve social function in this illness. Intact social function depends on the competent functioning of several cognitive domains that subserve perception of social cues and the generation of motivated social behavior. We propose to conduct a pharmacological challenge study of OT vs. placebo administration to study the effects of OT on specific components of social cognition in male deficit syndrome SCZ subjects. Primary Hypothesis: Intranasal OT will improve social cognition in subjects with deficit syndrome SCZ.

• Experimental

  Oxytocin

  The intranasal oxytocin intervention will be the administration of OT intranasally at a dose of three 4 IU puffs per nostril for a total dose of 24 IU. Each puff is 0.1ml in volume so the total volume administered will be 0.6 ml intranasally. This dose has been used in a number of other similarly designed challenge studies examining the effects of a single dose of OT (Kirsch et al. 2005; Kosfeld et al. 2005; Guastella et al. 2008a; Guastella et al. 2008b; Rimmele et al. 2009; Andari et al. 2010).

• Placebo comparator

  Placebo

  Intranasal placebo The PBO/control will consist of the OT vehicle administered as three puffs in each nostril. Each puff is is 0.1ml in volume so the total volume administered will be 0.6 ml intranasally. Treatment assignment will be by random allocation in blocks of six. Both experimenters and subjects will be blind to the treatment they are receiving.

• Other

  Healthy Controls

  Participants who have no psychiatric diagnosis and will be controls for this project. These controls will not receive oxytocin or placebo. They will only receive psychiatric screening interview, MATRICS Consensus Cognitive Battery (MCCB) assessment, urine drug screen, vision testing, and the three social cognition tasks.

1. Eye Tracking: Fixation Count

   Time frame · Day 1

   Registry description

   In order to assess the processing of social stimuli, subjects will be presented with a series of human faces of mixed sex and race showing neutral emotions and instructed to visually scan each face. Six regions of interest (ROIs) will be defined for each face stimulus: eyes, nose mouth, forehead, cheeks, and outside the contours of the face. The data will be processed off line for each face stimulus as the total time of fixation inside each of the ROIs. Refers to the number of fixations that occurred on the face of the stimulus presented to the participant during the eye-tracking assessment.

2. Eye Tracking: Dwell Duration Time

   Time frame · Day 1

   Registry description

   Refers to the amount of time that an individual spent looking at the face of the stimulus presented to the participant during the eye-tracking assessment.

3. Social Reward Ball-tossing Task

   Time frame · Day 1

   Registry description

   Subjects will perform a computerized Social Reward Ball-Tossing Task in which they decide to return the ball to one of three fictional partners. The photos of the partners and their reciprocity in returning the ball to the subject will be manipulated. The number of balls sent to each of the partners will be quantified to assess socially reinforced learning. The result is expressed in number of ball tosses sent to the subject by a fictional player with a positive expression MINUS the number of ball tosses sent to the subject by a fictional player with a negative expression. These measures will be compared between the control subjects, oxytocin and placebo group.

4. Non-Social Reward Ball-tossing Game

   Time frame · Day 1

   Registry description

   Social reward trials will be interleaved with non-social trials where subjects will play with random geometric shapes or landscape scenes associated with positive and negative non-social rewards. The outcome measure reported herein is the number of ball tosses the subject sends to shape A minus the number of ball tosses sent to shape B.

5. Facial Emotion Identification Task

   Time frame · Day 1

   Registry description

   The stimuli are 19 standard black and white pictures of faces showing one of six different emotions (happy, sad, angry, surprise, disgusted, ashamed) that were developed by Ekman and Friesen (1976). The pictures are shown for 15 sec, with 10 sec between each face. After the presentation of each face the subject is asked to choose which of the six emotions was displayed. The score on the test is the sum of correct responses. Subjects in the two groups (oxytocin vs. placebo) will be compared.