2. Suggested future trial.

Methods	Allocation: random Blinding: blind participants, treating team and raters. Duration: minimum one‐year follow‐up
Participants	Diagnosis: people with schizophrenia and aggression, on those with treatment‐resistant forms of the disorder and on those with schizoaffective disorders (alternatively, several trials are necessary) Age: Sex: male and female. n = 300
Interventions	1. Valproate in combination with any antipsychotic treatment: any dose 2. Placebo (or no intervention) in combination with any antipsychotic treatment
Outcome	Leaving the study early (due to any reason, inefficacy‐ and tolerability‐related adverse events) Service utilisation Global state ‐ clinically important change* Relapse Mental state ‐ clinically important change (general and specific) Behaviour ‐ clinically important change Aggression ‐ clinically important change Social functioning ‐ clinically important change Adverse effects ‐ clinically important general adverse effects*; sudden and unexpected death Economic outcomes Satisfaction with treatment Quality of life Pharmacokinetic interactions All outcomes by time ‐ short term (up to 12 weeks), medium term (13‐26 weeks) and long term (over 26 weeks)
Notes	*Primary outcomes of interest