Conditions: Schizophrenia Schizoaffective Disorder Schizophreniform Disorder
Allocation: RANDOMIZED | Intervention model: CROSSOVER
Enrollment: 350
Healthy volunteers: no

Brief summary:
The main aim of the trial is to study whether a change of medication in non-responders to a two-weeks antipsychotic drug trial is more effective than continued treatment with the same antipsychotic. Hypothesis: Non-responders who are switched at 2 weeks to another antipsychotic are more frequently in symptomatic remission at week 8 than non-responders who stay on the same antipsychotic

Detailed description:
The patients will be randomised to a double-blind 2 week run in phase with fixed doses of either oral amisulpride 800 mg/day or olanzapine 20mg/day.

Those participants who have not responded to treatment at two weeks (PANSS improvement \<25%) will be randomised to a 6 week double blind flexible dose phase:

1. Experimental intervention: switch to the other antipsychotic (oral olanzapine 5-20mg/d or oral amisulpride 200-800 mg/d)
2. Control intervention: continuation with the same drug as in the first 2 weeks in flexible dose ranges as above for another six weeks Those participants who have responded at week 2 (≥25% PANSS reduction) will continue on the same drug in flexible dose ranges as above Total duration of intervention per patient: 8 weeks

Arms:
arm 1: None arm 2: None arm 3: None arm 4: None arm 5: None

Interventions: intervention 1: Olanzapine or amisulpride
Intervention descriptions: intervention 1: Oral olanzapine 5mg to 20mg/d OR oral amisulpride 200mg to 800mg/d; both preferably once daily, both encapsulated for blinding

Protocol document: