Background: Second-generation antipsychotic drugs were introduced over a decade ago for the treatment of schizophrenia; however, their purported clinical effectiveness compared with first-generation antipsychotic drugs is still debated. We aimed to compare the effectiveness of second-generation antipsychotic drugs with that of a low dose of haloperidol, in first-episode schizophrenia.
Methods: We did an open randomised controlled trial of haloperidol versus second-generation antipsychotic drugs in 50 sites, in 14 countries. Eligible patients were aged 18-40 years, and met diagnostic criteria for schizophrenia, schizophreniform disorder, or schizoaffective disorder. 498 patients were randomly assigned by a web-based online system to haloperidol (1-4 mg per day; n=103), amisulpride (200-800 mg per day; n=104), olanzapine (5-20 mg per day; n=105), quetiapine (200-750 mg per day; n=104), or ziprasidone (40-160 mg per day; n=82); follow-up was at 1 year. The primary outcome measure was all-cause treatment discontinuation. Patients and their treating physicians were not blinded to the assigned treatment. Analysis was by intention to treat. This study is registered as an International Standard Randomised Controlled Trial, number ISRCTN68736636.
Findings: The number of patients who discontinued treatment for any cause within 12 months was 63 (Kaplan-Meier estimate 72%) for haloperidol, 32 (40%) for amisulpride, 30 (33%) for olanzapine, 51 (53%) for quetiapine, and 31 (45%) for ziprasidone. Comparisons with haloperidol showed lower risks for any-cause discontinuation with amisulpride (hazard ratio [HR] 0.37, [95% CI 0.24-0.57]), olanzapine (HR 0.28 [0.18-0.43]), quetiapine (HR 0.52 [0.35-0.76]), and ziprasidone (HR 0.51 [0.32-0.81]). However, symptom reductions were virtually the same in all the groups, at around 60%.
Interpretation: This pragmatic trial suggests that clinically meaningful antipsychotic treatment of first-episode of schizophrenia is achievable, for at least 1 year. However, we cannot conclude that second-generation drugs are more efficacious than is haloperidol, since discontinuation rates are not necessarily consistent with symptomatic improvement.