Omega-3 fatty acids for psychiatric illness

In a double-blind RCT of 81 adolescents and young adults (age 13 to 25) at ultra-high risk of psychotic illness, 5% of patients who received 1.2 g/d of omega-3 FAs developed a psychotic disorder compared with 28% of patients receiving placebo.²⁵ The authors concluded that supplementation with omega-3 FAs may be a safe and effective strategy for young patients with subthreshold psychotic symptoms.

Dementia

Studies evaluating the relationship between omega-3 FAs and dementia risk have revealed mixed findings.^26,27 In a pilot study of 10 geriatric patients with moderately severe dementia related to thrombotic cerebrovascular disorder, DHA supplementation led to improved Hamilton Depression Rating Scale and Mini-Mental State Examination (MMSE) scores compared with controls.²⁸ In another study, administering EPA to 64 patients with Alzheimer’s disease significantly improved MMSE scores, with maximum improvement at 3 months, but this benefit dissipated after 6 months of treatment.²⁹ In a study of 22 patients with various types of dementia, Suzuki et al³⁰ found that DHA supplementation improved scores on a Japanese dementia scale. These studies show promise, but more evidence is necessary before recommendations can be made.

Other psychiatric disorders

Omega-3 FAs as monotherapy or an adjunct to psychostimulants does not seem to improve symptoms in children who meet DSM-IV-TR criteria for attention-deficit/hyperactivity disorder (ADHD).^31-33 Studies of omega-3 FAs as treatment for anxiety and personality disorders are limited. To date, omega-3 FAs as adjunctive treatment in obsessive-compulsive disorder (OCD) and monotherapy in borderline personality disorder have not shown efficacy.^34,35

Using omega-3 FAs in practice

Based on new data and several recent meta-analyses, clinical recommendations have emerged. Sarris et al¹⁷ suggested patients with BD increase dietary intake of omega-3 FAs or take a supplement with 1 to 1.5 g/d of mixed EPA and DHA (with a higher ratio of EPA). In MDD, the type of omega-3 FA supplementation seems to be important; EPA seems to be the primary component for efficacy.^15,19 Additionally, the more severe the depression, the more likely symptoms will respond to omega-3 FAs.^6,14,15 Omega-3 FAs are not effective at preventing depression^14,15 and evidence is equivocal for treating perinatal depression.²¹ Omega-3 FA supplementation has not shown efficacy for patients with schizophrenia,^23,24 although it may prevent transition to psychosis in adolescents and young adults at ultra-high risk for a psychotic disorder.²⁵ Data examining omega-3 FA supplementation in postpartum depression²² and dementia^28,29 are limited but show promise. Omega-3 FAs appear to lack efficacy in ADHD,^31-33 OCD,³⁴ and borderline personality disorder.³⁵

Related Resources

• National Center for Complementary and Alternative Medicine. Omega-3 fatty acids. https://nccam.nih.gov/health/omega3.
• National Institutes of Health. Office of Dietary Supplements. Working group report: Omega-3 fatty acids and cardiovascular disease. https://ods.od.nih.gov/Health_Information/omega_3_fatty_acids.aspx.

Disclosure

Dr. Morreale reports no financial relationship with any company whose products are mentioned in this article or with manufacturers of competing products.