A meta-analysis of placebo-controlled trials of omega-3 fatty acid augmentation in schizophrenia: Possible stage-specific effects

BACKGROUND:

Omega-3 fatty acids have shown promise as an adjunctive treatment for schizophrenia. However, efficacy across studies has been inconsistent. We conducted a meta-analysis of published controlled studies with the goal of detecting different efficacy profiles at various stages of schizophrenia.

METHODS:

An online search was conducted for randomized, double-blind, placebo-controlled clinical trials, and a meta-analysis was conducted.

RESULTS:

Ten studies met the criteria for inclusion. Among patients in the prodromal phase of schizophrenia, omega-3 supplementation reduced psychotic symptom severity and lowered conversion rates to first-episode
psychosis. In patients with first-episode schizophrenia, omega-3 decreased nonpsychotic symptoms, required lower antipsychotic medication dosages, and improved early treatment response rates. Omega-3 had mixed results in patients with stable chronic schizophrenia, with only some patients experiencing significant benefits. Among patients with chronic schizophrenia, use of omega-3 fatty acids both by those experiencing acute exacerbations and those who had discontinued antipsychotic medications resulted in worsening of psychotic symptoms.

CONCLUSIONS:

The data suggest that omega-3 fatty acids may be efficacious in reducing clinical symptoms for patients in the earlier stages of schizophrenia (prodrome and first episode), while producing mixed results for patients
in the chronic stages. Based on these results, omega-3 fatty acids would not
be recommended for acute exacerbations in patients with chronic schizophrenia
nor for relapse prevention after discontinuation of antipsychotics.