Study protocol for a randomized controlled trial with rituximab for psychotic disorder in adults (RCT-Rits)

Area of Science:

• Neuroscience
• Immunology
• Psychiatry

Background:

• Inflammation is increasingly recognized in schizophrenia etiology.
• Autoimmune diseases and infections are risk factors; elevated inflammatory markers correlate with increased schizophrenia risk.
• Individuals with schizophrenia exhibit higher pro-inflammatory cytokine levels.

Purpose of the Study:

• To assess if rituximab (anti-CD20 monoclonal antibody) ameliorates psychotic symptoms in adults with schizophrenia or schizoaffective disorder.
• To explore potential mechanisms of action and identify pre-treatment biomarkers of response.
• To qualitatively investigate patient and informant experiences with the trial.

Main Methods:

• A randomized, double-blind, placebo-controlled trial involving 120 participants with schizophrenia spectrum disorders (SSD).
• Participants receive one intravenous infusion of rituximab (1000 mg) or saline.
• Psychiatric assessments, blood samples, and optional neuroimaging/lumbar puncture collected at multiple time points; qualitative interviews conducted with a subset.

Main Results:

• This is the first randomized controlled trial (RCT) of add-on rituximab in unselected SSD patients.
• Data collection ongoing; results pending.
• Qualitative data will provide insights into patient-reported outcomes and experiences.

Conclusions:

• Rituximab holds potential to transform treatment for psychotic disorders if effective.
• The study may increase awareness of immune-psychiatric links and reduce associated stigma.