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

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

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

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)