Do essential fatty acids have a role in the treatment of depression?

Nutraceuticals for major depressive disorder- more is not merrier: An 8-week double-blind, randomised, controlled trial

BACKGROUND

One of the most pressing questions in "Nutritional Psychiatry" is whether using combinations of different nutraceuticals with putative antidepressant activity may provide an enhanced synergistic antidepressant effect.

METHODS

A phase II/III, Australian multi-site, 8-week, double-blind, RCT involving 158 outpatients with a DSM-5 diagnosis of MDD. The intervention consisted of a nutraceutical combination: S-adenosyl methionine; Folinic acid; Omega-3 fatty acids; 5-HTP, Zinc picolinate, and relevant co-factors versus placebo. The primary outcome was change in MADRS score. Hypothesis-driven analyses of potential moderators of response involving key SNPs, and BDNF were also conducted.

RESULTS

Placebo was superior to the nutraceutical combination in reducing MADRS score (differential reduction -1.75 points), however a mixed linear model revealed a non-significant Group X Time interaction (p = 0.33). Response rates were 40% for the active intervention and 51% for the placebo; remission rates were 34% and 43% for active and placebo groups, respectively. No significant differences were found between groups on any other secondary depression, anxiety, psychosocial, or sleep outcome measures. Key SNPs and BDNF did not significantly moderate response. No significant differences occurred between groups for total adverse effects, aside from more nausea in the active group.

LIMITATIONS

Very high placebo response rates suggest a placebo run-in design may have been valuable.

INTERPRETATION

The adoption of a nutraceutical 'shotgun' approach to treating MDD was not supported, and appeared to be less effective than adding placebo to treatment as usual.

Associations between depressive symptomatology, diet, and body mass index among participants in the supplemental nutrition assistance program

BACKGROUND

Participation in the Supplemental Nutrition Assistance Program (SNAP) has been shown to increase food security, or access to adequate food; however, SNAP participation has also been associated with obesity among certain demographic groups (eg, women, but not men and children), possibly due to poorer dietary quality. Depressive symptomatology is an understudied factor, which is associated with obesity across the lifespan.

OBJECTIVE

This study examined the relationship between depressive symptomatology, dietary quality, and body weight among a sample of SNAP participants (n=639).

DESIGN

The analysis was cross-sectional; survey data were collected in May to December 2011 by trained data collectors.

PARTICIPANTS/SETTING

Adults who self-identified as the primary food shopper of the household in two predominantly low-income African-American neighborhoods characterized as "food deserts" in Pittsburgh, PA, were recruited to participate in this study.

MEASURES

Dietary quality was calculated using the US Department of Agriculture's Healthy Eating Index-2005. Body mass index (BMI; calculated as kg/m(2)) was based on objective measurements taken by the interviewer. Current depressive symptomatology was assessed by a trained interviewer using the Patient Health Questionnaire-2.

STATISTICAL ANALYSES PERFORMED

Descriptive statistics (means and percentages); two multivariate ordinary least-square regression analyses predicting BMI and dietary quality from depressive symptomatology while controlling for sociodemographic factors and food insecurity were performed.

RESULTS

Depression was a strong and statistically significant predictor of both dietary quality and BMI; higher score in depressive symptomatology was associated with lower scores in dietary quality (β=-1.26; P<0.0001). A higher score in depressive symptomatology was associated with higher BMI (β=.63; P=0.0031).

CONCLUSIONS

These findings show that depressive symptomatology is significantly associated with weight-related outcomes and suggests that understanding the risk of depression among SNAP participants could be important to understanding the relationships among SNAP participation, diet, and weight. The association between depressive symptomology, elevated BMI, and lower dietary quality among low-income, primarily African-American residents living in a food desert suggests the potential for mental health interventions to have broader benefits in this population. However, the directionality of this association is unclear and improving diet and reducing weight might also improve mental health symptoms. Additional longitudinal studies should assess these possibilities.

A combined supplementation of omega-3 fatty acids and micronutrients (folic acid, vitamin B12) reduces oxidative stress markers in a rat model of pregnancy induced hypertension

Objectives

Our earlier studies have highlighted that an altered one carbon metabolism (vitamin B₁₂, folic acid, and docosahexaenoic acid) is associated with preeclampsia. Preeclampsia is also known to be associated with oxidative stress and inflammation. The current study examines whether maternal folic acid, vitamin B₁₂ and omega-3 fatty acid supplementation given either individually or in combination can ameliorate the oxidative stress markers in a rat model of pregnancy induced hypertension (PIH).

Materials and Methods

Pregnant Wistar rats were assigned to control and five treatment groups: PIH; PIH + vitamin B₁₂; PIH + folic acid; PIH + Omega-3 fatty acids and PIH + combined micronutrient supplementation (vitamin B₁₂ + folic acid + omega-3 fatty acids). L-Nitroarginine methylester (L-NAME; 50 mg/kg body weight/day) was used to induce hypertension during pregnancy. Blood Pressure (BP) was recorded during pregnancy and dams were dissected at d20 of gestation.

Results

Animals from the PIH group demonstrated higher (p<0.01 for both) systolic and diastolic BP; lower (p<0.01) pup weight; higher dam plasma homocysteine (p<0.05) and dam and offspring malondialdehyde (MDA) (p<0.01), lower (p<0.05) placental and offspring liver DHA and higher (p<0.01) tumor necrosis factor–alpha (TNF–ά) levels as compared to control. Individual micronutrient supplementation did not offer much benefit. In contrast, combined supplementation lowered systolic BP, homocysteine, MDA and placental TNF-ά levels in dams and liver MDA and protein carbonyl in the offspring as compared to PIH group.

Conclusion

Key constituents of one carbon cycle (folic acid, vitamin B₁₂ and DHA) may play a role in reducing oxidative stress and inflammation in preeclampsia.

Current evidence regarding the management of mood and anxiety disorders using complementary and alternative medicine

This article is an updated review on the potential uses of complementary and alternative medicine (CAM) approaches for the management of patients with mood and anxiety disorders. We have focused this current paper on the different types of disorders and the CAM intervention which might be useful. This is in distinction to the prior paper which focused on the CAM interventions. In addition, we have provided a discussion of more recent studies that help to further inform practitioners about CAM interventions in these disorders. Mood and anxiety disorders are among the most prevalent mental health issues affecting people today and there are many approaches towards their management. CAM interventions can include supplements, botanical remedies, meditation and spiritual practices, acupuncture, and dietary practices. There are a growing number of research studies on the effectiveness of CAM interventions in mood and anxiety disorders, and this review evaluates and critiques such data.

Treatment of recurrent depression

Approximately eight out of ten people experiencing a major depressive episode will have one or more further episodes during their lifetime: a recurrent major depressive disorder. Prolongation or lifelong pharmacotherapy has emerged as the main therapeutic tool for preventing relapse in depression. However, outcome after discontinuation of antidepressants does not seem to be affected by the duration of their administration. Loss of clinical effects, despite adequate compliance, has also emerged as a vexing clinical problem. Use of intermittent pharmacotherapy with follow-up visits is another therapeutic option that would leave patients with periods free of drugs and side effects, in consideration of the fact that a high proportion of patients would discontinue the antidepressant anyway. However, the problems of resistance (the fact that a drug treatment may be associated with a diminished chance of response in those patients who successfully responded to it, but discontinued it) and of discontinuation syndromes are a substantial disadvantage of this therapeutic option. In recent years, several controlled trials have suggested that a sequential use of pharmacotherapy in the treatment of the acute episode and psychotherapy in its residual phase may improve long-term outcome. However, patients should be motivated for psychotherapy and skilled therapists should be available. It is important to discuss with the patient the various therapeutic options and to adapt strategies to the specific needs of patients.

Healthy Eating Index scores associated with symptoms of depression in Cuban-Americans with and without type 2 diabetes: a cross sectional study

BACKGROUND

Low diet quality and depression symptoms are independently associated with poor glycemic control in subjects with type 2 diabetes (T2D); however, the relationship between them is unclear. The aim of this study was to determine the association between diet quality and symptoms of depression among Cuban-Americans with and without T2D living in South Florida.

METHODS

Subjects (n = 356) were recruited from randomly selected mailing list. Diet quality was determined using the Healthy Eating Index-2005 (HEI-05) score. Symptoms of depression were assessed using the Beck Depression Inventory (BDI). Both linear and logistic regression analyses were run to determine whether or not these two variables were related. Symptoms of depression was the dependent variable and independent variables included HEI-05, gender, age, marital status, BMI, education level, A1C, employment status, depression medication, duration of diabetes, and diabetes status. Analysis of covariance was used to test for interactions among variables.

RESULTS

An interaction between diabetes status, gender and HEI-05 was found (P = 0.011). Among males with a HEI-05 score ≤ 55.6, those with T2D had a higher mean BDI score than those without T2D (11.6 vs. 6.6 respectively, P = 0.028). Among males and females with a HEI-05 score ≤ 55.6, females without T2D had a higher mean BDI score compared to males without T2D (11.0 vs. 6.6 respectively, P = 0.012)

CONCLUSIONS

Differences in symptoms of depression according to diabetes status and gender are found in Cuban-Americans with low diet quality.

Fatty acids intake and depressive symptomatology in a Greek sample: an epidemiological analysis

BACKGROUND

Depression is associated with an increased risk of cardiovascular disease, but the association with dietary habits is not well understood. The aim of this work was to statistically model the association of depressive symptoms with fatty acids intake in persons free of cardiovascular disease.

METHOD

A random multistage sampling, stratified by gender and age, was performed during 2001-2002. In the present work, psychological and dietary data from 453 men (19-89 years) and 400 women (18-84 years) were analyzed. Depression was assessed with the Zung's Self-rating Depression Scale (ZDRS). After a validation for the investigated population, plasma fatty acids in the form of their methyl esters were determined by gas chromatography, while dietary fatty acids were determined through a semiquantitative food frequency questionnaire and local food composition tables.

RESULTS

Women had significantly higher scores on the ZDRS as compared with men (47 ± 9 vs. 43 ± 10, p < 0.001). Multiadjusted data analysis after adjusting for age, gender, lifestyle, and dietary habits revealed that increased polyunsaturated fatty acid (PUFA) and monounsaturated fatty acid (MUFA) concentrations, and, more specifically, high concentrations of plasma total n-3 fatty acids (b ± SE: -1.9 ± 0.5, p  =  0.03), docosahexaenoic acid (-2.91 ± 1.04, p  =  0.02), eicosapentaenoic acid (-2.54 ± 0.84, p  =  0.03), α-linoleic acid (-16.8 ± 7.3, p  =  0.01), and linoleic acid (-3.97 ± 0.21, p  =  0.03), were associated with lower scores in the depression scale used.

CONCLUSION

These results indicate that increased PUFA and MUFA concentrations are associated with diminished depressive symptomatology among apparently healthy adults.

Complementary and alternative medicine therapies in mood disorders

This article reviews the potential uses of complementary and alternative medicine (CAM) techniques for individuals with mood disorders. Mood disorders are among the most prevalent mental health issues today and there are many approaches towards their management. While many different types of medication are available, more and more people turn to CAM interventions to help manage their mood disorders. CAM interventions can include herbal remedies, acupuncture and meditation. There is an increasing number of research studies on CAM intervention in mood disorders, and this article critiques such data and attempts to provide a clinical perspective within which these CAM interventions might be considered.

Higher Healthy Eating Index-2005 scores associated with reduced symptoms of depression in an urban population: findings from the Healthy Aging in Neighborhoods of Diversity Across the Life Span (HANDLS) study

BACKGROUND

Depression affects more than 15 million Americans in a given year. Compared to physical health, less is known about the affect of diet quality on symptoms of depression.

OBJECTIVE

This study investigated the relationship between diet quality and reported symptoms of depression in a low-income urban population.

SUBJECTS/SETTING

Subjects included 1,118 African-American and white adults, aged 30 to 64 years, living in Baltimore, MD, and represented a subsample of the initial examination and recruitment phase of the Healthy Aging in Neighborhoods of Diversity across the Life Span study.

METHODS

Nutrition data were based on two 24-hour dietary recalls collected by trained interviewers using the US Department of Agriculture Automated Multiple Pass Method. Diet quality was calculated using the US Department of Agriculture Healthy Eating Index (HEI)-2005. Depressive symptoms were assessed by a trained interviewer using the Center for Epidemiologic Studies Depression scale.

STATISTICAL ANALYSIS

Both linear and logistic regression analyses were used to examine whether or not diet quality was associated with depressive symptoms. The dependent variable was depressive symptoms and independent variables included HEI-2005, race, sex, age, education, income, and food-assistance program participation.

RESULTS

Mean HEI-2005 score was 52.17+/-0.40 (out of 100). Mean Center for Epidemiologic Studies Depression scale score was 11.64+/-0.25 (out of 40). Diet quality was significantly associated with reported symptoms of depression. However, income was a significantly stronger predictor of depression compared to diet quality, education, and sex.

CONCLUSIONS

Registered dietitians should be aware of relationships between psychological status and nutritional health when assisting clients to better manage their food choices to improve their overall health and quality of life.

Omega-3 fatty acids in depression: a review of three studies

We review three studies of omega-3 fatty acids in the treatment of depression that were carried out by our research group at the Beer Sheva Mental Health Center. The first study examined eicosapentaenoic acid (EPA) versus placebo as an adjunct to antidepressant treatment in 20 unipolar patients with recurrent major depression. The second study used omega-3 fatty acids in childhood major depression; 28 children aged 6-12 were randomized to omega-3 fatty acids or placebo as pharmacologic monotherapy. The third study was an open-label add-on trial of EPA in bipolar depression. Twelve bipolar outpatients with depressive symptoms were treated with 1.5-2.0 g/day of EPA for up to 6 months. In the adult unipolar depression study, highly significant benefits were found by week 3 of EPA treatment compared with placebo. In the child study, an analysis of variance (ANOVA) showed highly significant effects of omega-3 on each of the three rating scales. In the bipolar depression study, 8 of the 10 patients who completed at least 1 month of follow-up achieved a 50% or greater reduction in Hamilton depression (Ham-D) scores within 1 month. No significant side effects were reported in any of the studies. Omega-3 fatty acids were shown to be more effective than placebo for depression in both adults and children in small controlled studies and in an open study of bipolar depression. (This review discusses three studies, all from our group, completed before the clinical trial registry was initiated.)

Major depressive disorder and nutritional medicine: a review of monotherapies and adjuvant treatments

A literature review was conducted to examine the evidence for nutritional interventions in depression. It revealed a number of significant conclusions. Interestingly, more positive clinical trials were found to support adjuvant, rather than monotherapeutic, use of nutrients to treat depression. Much evidence exists in the area of adjuvant application of folic acid, S-adenosyl-methionine, omega-3, and L-tryptophan with antidepressants. Current evidence does not support omega-3 as an effective monotherapy to treat depression. However, this may be due, at least in part, to olive oil being used as the control intervention, some studies using docosahexaenoic acid alone or a higher docosahexaenoic acid to eicosapentaenoic acid ratio, and significant heterogeneity regarding depressive populations. Nevertheless, adjunctive prescription of omega-3 with antidepressants, or in people with dietary deficiency, may be beneficial. Inositol lacks evidence as an effective antidepressant and cannot be currently recommended. Evidence on the use of L-tryptophan for depression is inconclusive, and additional studies utilizing a more robust methodology are required.

Supplementation of a low dose of DHA or DHA+AA does not prevent peripartum depressive symptoms in a small population based sample

BACKGROUND

The decrease of maternal docosahexaenoic (DHA) status during pregnancy has been associated with postpartum depression, especially in women with a low intake of DHA. Since the DHA intake in the Netherlands is low, we investigated whether supplementation of low doses of DHA or DHA plus arachidonic acid (AA) during pregnancy and lactation could prevent depressive symptoms and sleep disturbances in this period.

METHODS

Women were supplemented daily with placebo, DHA (220 mg) or DHA+AA (220 mg each) from week 16 of pregnancy till three months postpartum. Fatty acid analyses were performed in the available plasma samples at 16 and 36 weeks of pregnancy. Depressive symptoms were measured in weeks 16 and 36 of pregnancy and six weeks postpartum using EPDS and within one week postpartum using a blues questionnaire.

RESULTS

119 women completed the study. The average frequency of fish intake was low, 0.94 times per week, and did not differ between the groups. The supplementation groups did not differ in mean EPDS scores or changes in EPDS scores, nor in incidence or severity of postpartum blues. Red blood cell DHA, AA and DHA/AA ratio did not correlate with EPDS or blues scores. Indices of sleep quality did not differ between the groups.

CONCLUSION

Supplementation of 220 mg/day DHA or DHA+AA (220 mg/day each) does not prevent peri-partum depressive symptoms, in a population based sample with low background DHA intake.

TRIAL REGISTRATION

ISRCTN Register nr. ISRCTN58176213.

Efficacy of omega-3 fatty acid supplementation on improvement of bipolar symptoms: a systematic review

The purpose of this review was to examine the current level of evidence regarding the efficacy of omega-3 fatty acid supplementation in improving bipolar disorder symptoms. Of 99 articles meeting initial search criteria, 5 randomized control trials and 2 quasi-experimental studies were selected for review. Omega-3 fatty acid supplementation was effective in 4 of 7 studies. Those using an omega-3 combination of eicosapentaenoic acid and docosahexanoic acid demonstrated a statistically significant improvement in bipolar symptoms, whereas those using a single constituent did not. Dosage variations did not demonstrate statistically significant differences. Due to its benign side effect profile and some evidence supporting its usefulness in bipolar illness, omega-3 may be a helpful adjunct in treatment of selected patients. Future studies are needed to conclusively confirm the efficacy of omega-3s in bipolar disorder, uncovering a new well-tolerated treatment option.

Self-help interventions for depressive disorders and depressive symptoms: a systematic review

BACKGROUND

Research suggests that depressive disorders exist on a continuum, with subthreshold symptoms causing considerable population burden and increasing individual risk of developing major depressive disorder. An alternative strategy to professional treatment of subthreshold depression is population promotion of effective self-help interventions that can be easily applied by an individual without professional guidance. The evidence for self-help interventions for depressive symptoms is reviewed in the present work, with the aim of identifying promising interventions that could inform future health promotion campaigns or stimulate further research.

METHODS

A literature search for randomised controlled trials investigating self-help interventions for depressive disorders or depressive symptoms was performed using PubMed, PsycINFO and the Cochrane Database of Systematic Reviews. Reference lists and citations of included studies were also checked. Studies were grouped into those involving participants with depressive disorders or a high level of depressive symptoms, or non-clinically depressed participants not selected for depression. A number of exclusion criteria were applied, including trials with small sample sizes and where the intervention was adjunctive to antidepressants or psychotherapy.

RESULTS

The majority of interventions searched had no relevant evidence to review. Of the 38 interventions reviewed, the ones with the best evidence of efficacy in depressive disorders were S-adenosylmethionine, St John's wort, bibliotherapy, computerised interventions, distraction, relaxation training, exercise, pleasant activities, sleep deprivation, and light therapy. A number of other interventions showed promise but had received less research attention. Research in non-clinical samples indicated immediate beneficial effects on depressed mood for distraction, exercise, humour, music, negative air ionisation, and singing; while potential for helpful longer-term effects was found for autogenic training, light therapy, omega 3 fatty acids, pets, and prayer. Many of the trials were poor quality and may not generalize to self-help without professional guidance.

CONCLUSION

A number of self-help interventions have promising evidence for reducing subthreshold depressive symptoms. Other forms of evidence such as expert consensus may be more appropriate for interventions that are not feasible to evaluate in randomised controlled trials. There needs to be evaluation of whether promotion to the public of effective self-help strategies for subthreshold depressive symptoms could delay or prevent onset of depressive illness, reduce functional impairment, and prevent progression to other undesirable outcomes such as harmful use of substances.

Plasma eicosapentaenoic acid is inversely associated with severity of depressive symptomatology in the elderly: data from the Bordeaux sample of the Three-City Study

BACKGROUND

Depressive symptoms are commonly observed in elderly people, and nutritional factors such as polyunsaturated fatty acids (PUFAs) have been proposed as potential protective determinants of depressive disorders.

OBJECTIVE

The objective was to analyze the relation between plasma fatty acids and severity of depressive symptomatology (DS) in French elderly community dwellers.

DESIGN

The study population (mean age: 74.6 y) consisted of 1390 subjects from Bordeaux (France) included in the Three-City Study cohort. DS was evaluated by using the Center for Epidemiologic Studies Depression scale. The use of antidepressant drugs was recorded. The proportion of each plasma fatty acid was determined. Cross-sectional analysis of the association between plasma fatty acids and severity of DS was performed by multilinear regression.

RESULTS

Compared with control subjects, subjects with DS were older, were more often women, were more often widowed or single, were of lower income, were receiving antidepressant treatment more frequently, had a lower incidence of hypercholesterolemia, and had lower Mini-Mental State Examination scores (mean: -1.1 point; P < 0.0001). Plasma eicosapentaenoic acid (EPA) was lower in the subjects with DS than in the control subjects (0.85% compared with 1.01%; P = 0.001). There were no significant differences in any other fatty acid. When adjusted for potential confounders, such as sociodemographic characteristics and health indicators, plasma EPA was inversely associated with the severity of DS (beta = -0.170, P = 0.040) in subjects taking antidepressants.

CONCLUSION

Higher plasma EPA was associated with a lower severity of DS in elderly subjects, especially those taking antidepressants.

The antidepressant role of dietary long-chain polyunsaturated n-3 fatty acids in two phases in the developing brain

In this work we investigated the effect from fish oil (FO) supplementation, rich in n-3 fatty acids, on an antidepressant effect on adult rats in Phase A (supplementation during pregnancy and lactation) and phase B (supplementation during post-weaning until adulthood). During Phase A, female rats, used as matrix to obtain male rats, were divided in three groups: FO (daily supplemented), CF (coconut fat daily supplemented) and control (not supplemented). Our results showed that adult rats whose mothers were supplemented with FO during Phase A and rats supplemented during phase B demonstrated a significantly decreased immobility time when compared to control and CF groups. There was no difference in neither motor activity nor anxiety behavior in the three groups excluding false positive results. Our results suggest that n-3 fatty acids supplementation during Phases A and B had a beneficial effect on preventing the development of depression-like behavior in adult rats.

Collaborative depression care, screening, diagnosis and specificity of depression treatments in the primary care setting

The identification, referral and specific treatment of midlife patients in primary care who are distressed by mood, anxiety, sleep and stress-related symptoms, with or without clinically confirmed menopausal symptoms, are confounded by many structural issues in the delivery of women's healthcare. Diagnosis, care delivery, affordability of treatment, time commitment for treatment, treatment specificity for a particular patient's symptoms and patient receptiveness to diagnosis and treatment all play roles in the successful amelioration of symptoms in this patient population. The value of screening for depression in primary care, the limitations of commonly used screening instruments relative to culture and ethnicity, and which clinical care systems make best use of diagnostic screening programs will be discussed in the context of the midlife woman. The Sequenced Treatment Alternatives to Relieve Depression (STAR*D) program illustrates the relatively high rate of unremitted patients, regardless of clinical setting, who are receiving antidepressants. Nonmedication treatment approaches, referred to in the literature as 'nonsomatic treatments', for depression, anxiety and stress, include different forms of cognitive-behavioral therapy, interpersonal therapy, structured daily activities, mindfulness therapies, relaxation treatment protocols and exercise. The specificity of these treatments, their mechanisms of action, the motivation and time commitment required of patients, and the availability of trained practitioners to deliver them are reviewed. Midlife women with menopausal symptoms and depression/anxiety comorbidity represent a challenging patient population for whom an individualized treatment plan is often necessary. Treatment for depression comorbid with distressing menopausal symptoms would be facilitated by the implementation of a collaborative care program for depression in the primary care setting.

Sequential treatment of depression in primary care

BACKGROUND

In the past decade, in clinical psychiatry several investigations suggested the usefulness of a sequential way of integrating pharmacotherapy and psychotherapy in mood disorders. The aim of this paper was to illustrate the practical implications of sequential treatment strategy for depression in primary care, with particular reference to the increasingly common problem of recurrent depression.

METHODS

The Authors tried to integrate the evidence which derives from meta-analyses and comprehensive general reviews with the insights which derive from controlled studies concerned with specific populations.

CONCLUSIONS

The sequential treatment of mood disorders is an intensive, two-stage approach, which derives from the awareness that one course of treatment with a specific tool (whether pharmacotherapy or psychotherapy) is unlikely to entail solution to the affective disturbances of patients, both in research and in clinical practice settings. The aim of the sequential approach is to add therapeutic ingredients as long as they are needed. In this sense, it introduces a conceptual shift in clinical practice.

Clinical trials of PUFAs in depression: State of the art

Omega fatty acid treatment of depression is an unusual story in psychopharmacology in that the use and study of these compounds were advanced in cardiovascular disease before becoming of interest in psychiatry. Given the absence of an easily patentable derivative it is a tribute to the field that enough studies have accumulated for a reasonable review of omega-3 treatment of depression at this time. On the other hand, it is clearly not possible to compare the number of studies, variety of studies and the number of participants in each study with Federal Drug Administration style registration trials of patented antidepressant drugs. Most of the available studies of omega-3 in depression have been investigator initiated and use add-on design. This paper reviews 12 published and as yet unpublished clinical trials (all but one double-blind placebo-controlled) of polyunsaturated fatty acids in unipolar depression, bipolar disorder, and special populations with affective/depressive disorders. While overall results up to this point are encouraging, they are not unanimously positive. Outstanding issues that have not as yet been resolved include the dose of omega-3 necessary and the length of time required for significant response. Moreover, the complex issue of the relationship between two possible active ingredients, eicosapentaenoic acid and docosahexaenoic acid, remains unresolved.