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

J Affect Disord. 2008 Dec;111(2-3):351-9. doi: 10.1016/j.jad.2008.03.008. Epub 2008 May 15.


Background: Effect 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).

Method: Double-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.

Results: 29 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 > or = 50% reduction in MADRS score, 7 patients (22%) met criteria for remission (final MADRS total score < or = 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.

Conclusion: These 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.

Publication types

  • Comparative Study
  • Randomized Controlled Trial

MeSH terms

  • Aged
  • Antidepressive Agents / therapeutic use*
  • Antiparkinson Agents / therapeutic use
  • Brazil / epidemiology
  • Combined Modality Therapy
  • Comorbidity
  • Depressive Disorder, Major / diet therapy
  • Depressive Disorder, Major / drug therapy*
  • Depressive Disorder, Major / epidemiology
  • Dietary Supplements
  • Double-Blind Method
  • Fatty Acids, Omega-3 / administration & dosage
  • Fatty Acids, Omega-3 / therapeutic use*
  • Female
  • Humans
  • Levodopa / therapeutic use
  • Male
  • Middle Aged
  • Mineral Oil / therapeutic use
  • Parkinson Disease / drug therapy
  • Parkinson Disease / epidemiology*
  • Parkinson Disease / psychology*
  • Personality Inventory
  • Pilot Projects
  • Placebos
  • Psychiatric Status Rating Scales / statistics & numerical data
  • Treatment Outcome


  • Antidepressive Agents
  • Antiparkinson Agents
  • Fatty Acids, Omega-3
  • Placebos
  • Levodopa
  • Mineral Oil