Depression in Parkinson's disease: A double-blind, randomized, placebo-controlled pilot study of omega-3 fatty-acid supplementation

BackgroundEffect of fish oil supplementation in parkinsonian patients with depression measured by Montgomery–Asberg Rating Scale (MADRS), the Clinical Global Impressions Scale (CGI) and Beck Depression Inventory (BECK).MethodDouble-blind, placebo-controlled study analyzed depression in 31 patients with Parkinson's Disease and Major Depression (DSM-IV). The patients were double-blind separated in 2 groups that received fish oil (containing omega-3 fatty acids) or mineral oil capsules for 3 months; each group was separated in 2 new groups: one taking antidepressant medication and another one not taking it.Results29 patients completed the 12-week trial, 58% were female and the mean age was 64.4 years old. Patients supplemented with fish oil showed a significant decrease in MADRS and CGI-Depression scores, and there was no difference among groups in BDI. 14 patients (42%) met criteria for ≥ 50% reduction in MADRS score, 7 patients (22%) met criteria for remission (final MADRS total score ≤ 12), and 2 patients (6%) discontinued supplementation of fish oil. HPLC analysis of fatty-acid profile showed increase of omega-3 fatty acid in the erythrocyte membrane of patients taking fish oil.ConclusionThese results reveal that PD patients taking fish oil, with or without antidepressants, presented improvement in depressive symptoms and indicate that the intake of omega-3 can be used with an antidepressant effect or as adjuvant therapy with some other medication. This is a first pilot study with parkinsonian patients and omega-3 supplementation and requires replication in a larger sample.