Depression is a serious mental health condition affecting individuals of all ages. But did you know there may be a connection between depression in youth and Omega-3 Index (O3i) levels?

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A recent study demonstrated that this essential fatty acid may play a crucial role in mental health, particularly in children. Understanding this relationship could open new possibilities for early intervention and preventive measures to address childhood and adolescent depression. This article will explore the current research on the Omega-3 Index and its potential implications for treating and preventing major depression in adolescence.


Depression in Youth

Occasional sadness or loneliness is part of every child and teen’s life. However, when these feelings persist, they may result in depression. Defined by the Mayo Clinic as a mood disorder that causes persistent sadness and loss of interest, depression is much more than a bout of the blues and may require long-term treatment.

Depression during adolescence has been associated with poor educational and social outcomes and increased risk of smoking, substance misuse, eating disorders, and obesity. Furthermore, depression during childhood and adolescence is a risk factor for chronic and recurrent forms of depression throughout life.

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According to the CDC, examples of behaviors that might be seen in children with depression include:

  • Feeling sad, hopeless, or irritable a lot of the time
  • Not wanting to do or enjoy doing fun things
  • Showing changes in eating or sleeping patterns – a lot more or a lot less than usual
  • Showing changes in energy – being tired, sluggish, tense, or restless
  • Having a hard time paying attention
  • Feeling worthless, useless, or guilty
  • Exhibiting self-injury or self-destructive behaviors

Major depressive disorder (MDD) and pediatric major depressive disorder (pMDD) are some of the most common psychiatric disorders during adolescence, with prevalence rates between 5-12% worldwide. Although the etiology of pMDD is unclear, increasing evidence suggests that nutrition may play a role in mental health, and a particular interest in omega-3 polyunsaturated fatty acids (PUFAs) has emerged.


Omega-3 Fatty Acids in Depressive Disorders

Long-chain omega-3 PUFAs docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA) are essential for the brain and body. Several lines of evidence support the importance of omega-3s in brain and mood disorders such as attention deficit hyperactivity disorder (ADHD), autism spectrum disorder (ASD), cognitive impairment, and depression.

Regarding the latter, EPA and DHA have been found to play essential roles in several processes involved in depression, such as myelination, neurogenesis, brain connectivity, neurotransmitter turnover, and inflammation.

Several publications have clearly defined correlations between omega-3 levels and depression outcomes in adult populations. A study published in Biological Psychiatry in 2010 conducted a meta-analysis of 14 studies comparing PUFA levels between depressive adult patients and controls.

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They found that compared with control subjects, the levels of EPA, DHA, and total omega-3s were significantly lower in depressive patients. A 2018 study found that prenatal depression prevalence and duration were significantly associated with lower DHA, EPA, and total omega-3 levels. Furthermore, several systematic reviews of omega-3s have demonstrated efficacy in treating MDD in adults (1, 2, 3, 4, 5), suggesting omega-3s play a vital role in mental health outcomes.

Few studies have explored the correlation between depression and omega-3 status in children and adolescents. One such study, conducted in Japan, included over 6,000 adolescents aged 12-15 and found that daily fish intake was inversely associated with depressive symptoms in boys (not girls).

Another study, conducted by Pottala et al. in 2012, compared the Omega-3 Index levels of 150 adolescents admitted to the hospital for depression to healthy matched controls and found that adolescent depression was associated with reduced Omega-3 Index levels. Moreover, preliminary data point towards the beneficial effects of omega-3 supplementation on pediatric depression, but more large-scale studies are needed to validate these results.

Since most of the research investigating the impacts of omega-3s on depression is conducted in adults, it’s hard to generalize these findings to adolescents. Children and adolescents are generally still developing and experiencing increased neuronal plasticity and vulnerability to environmental stressors.

Furthermore, adolescents often have increased nutrient needs due to the rapid growth and development of biological systems but regularly have a poorer diet quality than adults. Is poor nutrient status, including intake of omega-3 fatty acids, compromising adolescents’ resilience to depression and mood disorders?

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New Study Finds Associations Between Omega-3 Status & Pediatric Major Depressive Disorder

A new study published in July 2023 aimed to determine the associations of omega-3 intake and status with depression in Swiss adolescents with and without diagnosed pMDD. This observational case-control study included 95 adolescents aged 13-17 with diagnosed pMDD and 95 healthy matched controls.

Omega-3 status was analyzed using the Omega-3 Index, omega-3 intake was assessed using a food frequency questionnaire (FFQ), and depression severity was evaluated by the Children’s Depression Rating Scale-Revised (CDSR-R).

The researchers found that Omega-3 Index levels differed significantly between cases and controls, with differences among all types of fatty acids (FA). In this matched case-control study in Swiss adolescents, higher Omega-3 Index levels were associated with lower odds of depression. While no association between red blood cell ALA levels and depression was found, a higher omega-6/omega-3 PUFA ratio was associated with higher odds of depression.

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Furthermore, the proportion of adolescents with “very low” Omega-3 Index levels (<4%) and “low” Omega-3 Index levels (<6%) was significantly higher among those diagnosed with pMDD than among controls. Overall, 81% of participating adolescents had a low Omega-3 Index, and 20% had a very low Omega-3 Index.

Interestingly, the intake of omega-3 PUFAs (mg/day) and consumption frequency of omega-3 PUFA-rich sources assessed with the FFQ did not differ between those with pMDD and the controls. Thus, a higher Omega-3 Index is likely due to factors other than omega-3 consumption alone.

The researchers provide a few possible explanations, including differences in conversion rates between ALA to EPA and DHA, which can be affected by variables in genetics, hormone levels, sex, age, BMI, alcohol intake, or smoking.

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Another explanation provided points to inflammation. The researchers suggested that since chronic stress or emotional alterations have been shown to increase levels of AA-derived pro-inflammatory lipid mediators, which then stimulate action from anti-inflammatory mediators derived from EPA and DHA, adolescents dealing with psychosocial and environmental stressors may have an increased need for and use of omega-3s to combat chronic inflammation.

Overall, the authors concluded that these results demonstrate that lower Omega-3 Index levels are associated with pMDD in adolescents. However, differences in omega-3 status could not be explained by differences in omega-3 intake, and further investigations are required to understand the mechanisms underlying the relationship between omega-3s and pediatric depression. Furthermore, the high proportion of adolescents with low and very low Omega-3 Index levels suggests that public health measures may be required to improve omega-3 status in this population.


Omega-3 Dietary Intake Among Those with Depression

Omega-3 fatty acids are considered essential fatty acids, meaning they must be obtained through the diet. The European Food Safety Authority has DHA dietary recommendations for infants and toddlers aged 6-24 months (100 mg DHA/d), yet do not have recommendations for children aged 2-18 years.

The Institute of Medicine and the Academy of Nutrition and Dietetics have put forth recommendations for total Omega-3s (not specific recommendations for EPA, DHA, or other long-chain omega-3s), which vary from 0.5g/d to 1.6g/d from birth until 18 years of age.

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Without specific EPA + DHA dietary guidelines for adolescents, researchers have suggested that intake should be consistent with the adult population, which aims to achieve a mean daily intake of 250-500mg of DHA + EPA daily (equivalent to consuming 1-2 fatty fish meals per week). However, omega-3 recommendations for those with MDD or pMDD may be much higher, ranging from 750 mg/d to 2,000 mg/d (6, 7, 8, 9, 10).

Nonetheless, given the recent evidence indicating that omega-3 status does not always correlate with omega-3 intake, regular Omega-3 Index assessments could give adolescents a better idea of where they stand. Evidence suggests that an Omega-3 Index >6% is ideal for children and adolescents in the context of optimal cognitive development, and different children may require different amounts of omega-3 intake to hit those goals. More research is needed in children and teens to refine guidelines for these groups.

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Future Studies

The recent study conducted in Swiss teens found that a higher Omega-3 Index during adolescence is associated with a lower risk for pMDD, and a higher omega-6/omega-3 ratio is associated with a higher risk for pMDD.

Furthermore, the researchers found that differences in omega-3 intake did not explain the observed differences in omega-3 status between individuals with pMDD and matched controls.

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These findings highlight the importance of more research to determine the mechanisms underlying the relationship between omega-3s, omega-3 status, and pediatric depression. To that end, these researchers emphasize the importance of regular Omega-3 Index testing and monitoring since omega-3 consumption can’t, alone, ensure that omega-3 status is adequate.

Finally, the high proportion of participants with either very low or low Omega-3 Index levels suggests a need for public health measures to improve omega-3 status during adolescence. If you are interested in omega-3 supplementation, be sure to consult with your child’s primary care or mental health provider before adding supplements to their diet.

These statements have not been evaluated by the Food and Drug Administration. This test is not intended to diagnose, treat, cure, prevent or mitigate any disease. This site does not offer medical advice, and nothing contained herein is intended to establish a doctor/patient relationship. OmegaQuant, LLC is regulated under the Clinical Laboratory improvement Amendments of 1988 (CLIA) and is qualified to perform high complexity clinical testing. The performance characteristics of this test were determined by OmegaQuant, LLC. It has not been cleared or approved by the U.S. Food and Drug Administration.

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