Is fish oil promising in the treatment of depression during pregnancy and lactation?

Increasing concerns about neonatal syndromes following antidepressant use in the late phase of pregnancy(1) have caused more hesitation about their use. Although inadequate data about in utero exposure of antidepressants may present risks, the risks of untreated maternal depression must be considered as well. One candidate as an antidepressant is fish oil, in light of its omega-3 constituent.

Omega-3 fatty acids are long-chain, polyunsaturated fatty acids found in plant and marine sources and helpful in treating various medical conditions (2). Omega-3 fatty acids may prove to be efficacious in a number of psychiatric disorders. Evidence suggests that omega-3 fatty acids may have beneficial effects in mood disorders, including bothmajor depression and bipolar disorder, schizophrenia and dementia. Furthermore, omega-3 fatty acids may prove to be a safe and efficacious treatment for psychiatric disorders during pregnancy and breastfeeding (2).

Major depressive disorder (MDD) is prevalent among women of childbearing age. Approximately 15% of women experience an episode of perinatal depression (PND), antenatally and/or postnatally (3). Because there are increasing concerns about possible adverse effects of antidepressant medication use during pregnancy and in breastfeeding mothers (4), it is important to investigate possible alternative treatments. Main dietary risk factors of postnatal depression are low riboşavin, low folate, low docosahexaenoic acid, low eicosapantaenoic acid, low calcium, low magnesium and low zinc. Oil-rich fish are a rich source of n-3 fatty acids, in particular eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) (5). Evidence indicates that these fatty acids may be involved in the synthesis and regulation of brain neurotransmitters (dopamine, monoamine and serotonin), which are thought to be reduced in cases with depressive symptoms (6). More specifically, it is thought that high concentrations of DHA located in non-myelin cell membranes of the central nervous system may help support synaptic transmissions (7). Different human studies were identified investigating dietary and/or supplemental sources of n-3 in relation to the development of postnatal depression. Only two of these trials were randomised controlled trials (8,9). Among others, three studies support the theory that dietary and supplemental sources of n-3 are associated with fewer postnatal depression symptoms (8,10,11) and five studies contest this theory (12,13,14).