Omega-3 Benefits: Omega-3 and Depression

Omega-3 benefits in depression

There is a documented, statistically significant relationship between low plasma omega-3 values and negative mood among non-psychiatric patients (1). Deficiencies in these polyunsaturated fatty acids have also been observed in attention deficit hyperactivity disorder, depression, bipolar disorder, stress, aggression and dementia (2). The omega-6/omega-3 ratio in serum and red blood cell membranes is high in depression (3, 4) and in the risk of suicide (5): serum and red blood cell membrane values of omega-3 EPA, DHA and total long-chain omega-3 polyunsaturated fatty acids are significantly lower in depressive patients compared to control subjects (6-8).

Various studies indicate that depression shares the physiopathological characteristics and risk factors of cardiovascular disease (9-12). The inflammatory hypothesis of depression stems from the observation that stress precipitates both inflammatory responses and depression, inflammatory markers are higher and inflammatory cytokines can produce depressive symptoms in humans (13, 14). High omega-3 values in the omega-6/omega-3 ratio tend to reduce eicosanoid and proinflammatory cytokine production (15) and an improvement in mood disorders is observed when anti-inflammatory agents are used as an adjuvant to conventional treatment (16).

In addition, the omega-6/omega-3 ratio could also influence the physiopathology of depression via the catecholaminergic systems (serotonin and dopamine) (17, 18).

Omega-3 as adjuvant therapy

Supplementation with omega-3 fatty acids can reduce the symptoms of perinatal depression (19-21). Although the beneficial effect of omega-3 fatty acid supplementation in depression has mainly been observed when used as adjuvant therapy (22, 23), monotherapy with omega-3 has significant therapeutic effects in major childhood depression (24), while in adolescents with selective serotonin reuptake inhibitor (SSRI)-resistant depression, fish oil supplementation produced a remission in the symptoms in 40 to 100% of cases (dose dependent) (25).

Omega-3 EPA and depression

Omega-3 EPA is more effective than DHA in reducing symptoms of depression. Epidemiological and experimental studies have shown its clinical efficacy in people diagnosed with major depressive disorder and in those with depressive symptoms but not diagnosed as major depression (22, 23). The meta-analyses of clinical studies focussing on the type of omega-3 used in the treatment of depression show that the positive effect on depressive symptoms depends more on the omega-3 EPA than the DHA content of the treatment (26, 27). When comparing omega-3 EPA to DHA as adjuvants to maintenance medication in patients with depression, the response to treatment was only observed in patients treated with omega-3 EPA (28). And with major depression, effects equal to fluoxetine have been obtained with EPA, but combined administration of both produces a better result than with each separately (29).

Safety of omega-3 administration

The American Psychiatric Association recommends 1 gram of omega-3 DHA+EPA daily for the treatment of affective disorders and has proposed that the optimum proportion is 2 parts omega-3 EPA to one part DHA (30).

In psychiatric patients, in which interactions can prove a problem, supplementation with omega-3 does not represent a risk: omega-3 fatty acids are extremely safe in the long term.



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