The Effect of D-serine as add-on Therapy in Recent-onset Psychosis (DROP)

In psychotic disorders, negative symptoms and cognitive impairment are difficult to treat with antipsychotics, which are mostly effective for positive symptoms. However, it is important that negative symptoms and cognitive impairment are treated as well, as they both play a large part in the acute episode and long-term course of schizophrenia outcome. Previous studies have used D-serine as add-on treatment in patients with psy-chotic disorders and high-risk patients, with positive results. So far, no study has investigated the effects in a sample of recent-onset psychosis patients.

Therefore, this study will include 30 patients (18-50 years old) with recent-onset psychosis. In addition to their regular treatment, patients will receive either D-serine (2 g/d) or placebo for 6 weeks. D-serine is an amino-acid naturally occurring in the brain which is prescription-free available as nutritional supplement.

The primary outcome measure is total score on the Positive and Negative Syndrome Scale (PANSS). Secondary measure-ments include PANSS subscales, neurocognitive tests, (f)MRI, and EEG

Study Overview

• Status: Terminated
• Conditions: Psychotic Disorder
• Intervention / Treatment: Dietary supplement: D-serine; Other: Placebo

• Study Type: Interventional
• Enrollment (Actual): 3
• Phase: Not Applicable

Contacts and Locations

Study Locations

• Switzerland
  • Basel-Stadt
    • Basel, Basel-Stadt, Switzerland, 4002
      • UPK Basel

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 16 years to 48 years (Adult)
• Accepts Healthy Volunteers: No
• Genders Eligible for Study: All

Description

Inclusion Criteria:

• Age 18-50
• Recent onset psychosis (< 5 years of overt psychotic symptoms)
• Able to read and understand study procedures and participant's information

Exclusion Criteria:

• Clozapine use
• Suicidal ideation
• Psychotic disorders and symptoms associated with general medical conditions or substance abuse
• BMI > 30
• Renal impairment (history and creatin levels (< 80 ug/L for woman and < 97 ug/L for men))
• Hearing impairment
• Current or past (< 6 months) enrolment in another clinical trial with the primary outcome to improve symptoms
• Pregnant or lactating women (pregnancy test)

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Quadruple

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: D-serine group; Oral administration of 2g D-serine per day, for 6 weeks.	Dietary supplement: D-serine; Capsule D-serine
Placebo Comparator: Placebo group; Oral administration of 2g Placebo (Mannitol) per day, for 6 weeks.	Other: Placebo; Capsule D-serine

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Total symptom severity	total score on the Positive and Negative Syndrome Scale (PANSS). Lower scores indicate better outcome (min. 30 - max. 120).	change from baseline to 6 weeks

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Subscales symptom severity	Subscores (5-factor model) on the Positive and Negative Syndrome Scale (PANSS). Lower scores indicate better outcome.	change from baseline to 6 weeks
Symptom severity and treatment response	measured with the Clinical Global Impression Scale (CGI), lower scores indicate a better outcome	change from baseline to 6 weeks
Resting-state microstates	measured with resting-state electroencephalography (EEG). large-scale neural networks are investigated with EEG microstates Ocillations in the theta-band (4-7 Hz) and gamma-band (>30 Hz) will be assessed. measured with resting-state electroencephalography (EEG). Ocillations in the theta-band (4-7 Hz) and gamma-band (>30 Hz) will be assessed.	change from baseline to 6 weeks
Mismatch Negativity (MMN)	measured with EEG	change from baseline to 6 weeks
Intelligence	Part of neurocognitive testing. Higher scores indicate better outcome.	change from baseline to 6 weeks
Attention and processing speed	Part of neurocognitive testing. Higher scores indicate better outcome.	change from baseline to 6 weeks
Executive functioning	Part of neurocognitive testing. Higher scores indicate better outcome.	change from baseline to 6 weeks
Memory	Part of neurocognitive testing. Higher scores indicate better outcome.	change from baseline to 6 weeks

Collaborators and Investigators

• Sponsor: Dragos Inta

Study record dates

Study Major Dates

• Study Start (Actual): November 25, 2021
• Primary Completion (Actual): August 31, 2022
• Study Completion (Actual): August 31, 2022

Study Registration Dates

• First Submitted: October 18, 2019
• First Submitted That Met QC Criteria: October 24, 2019
• First Posted (Actual): October 28, 2019

Study Record Updates

• Last Update Posted (Actual): September 10, 2022
• Last Update Submitted That Met QC Criteria: September 6, 2022
• Last Verified: September 1, 2022

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Schizophrenia Spectrum and Other Psychotic Disorders; Psychotic Disorders; Mental Disorders
• Other Study ID Numbers: 2019-01699

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: No

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No