Depression in Parkinson's disease: a double-blind, randomized, placebo-controlled pilot study of omega-3 fatty-acid supplementation

Eicosapentaenoic acid versus docosahexaenoic acid in mild-to-moderate depression: a randomized, double-blind, placebo-controlled trial

Controversy exists as to whether eicosapentaenoic acid (EPA) or docosahexaenoic acid (DHA) or both are responsible for the efficacy of n-3 polyunsaturated fatty acids in depression. We conducted a single-center, randomized, double-blind, placebo-controlled, multi-arm, parallel-group trial, comparing the efficacy of EPA versus DHA as adjuvants to maintenance medication treatments for mild-to-moderate depression. Eighty-one mild-to-moderately depressed outpatients were randomly assigned to receive either 1g/d of EPA or DHA or placebo (coconut oil) for 12 weeks. The primary outcome measure was the 17-item Hamilton Depression Rating Scale (HDRS) final score in the modified intention-to-treat population, which comprised of all randomized patients with at least 1 post-randomization observation (n=62; 61.3% female; mean age 35.1 ± 1.2 years). Allocated treatments were well tolerated. Although there was no significant difference between groups at baseline, patients in the EPA group showed a significantly lower mean HDRS score at study endpoint compared with those in the DHA (p<0.001) or placebo (p=0.002) groups. Furthermore, response to treatment (defined as a ≥ 50% decrease from the baseline HDRS score) was only observed in 6 patients receiving EPA, while no one in any of DHA or placebo groups responded to treatment. Overall, these data suggest greater efficacy of EPA compared to DHA or placebo as an adjunctive treatment in mild-to-moderate depression. However, further, randomized controlled trials are needed to support these findings.

Omega-3 polyunsaturated fatty acid (PUFA) status in major depressive disorder with comorbid anxiety disorders

BACKGROUND

Although lower levels of omega-3 polyunsaturated fatty acids (PUFAs) are found in major depressive disorder, less is known about PUFA status and anxiety disorders.

METHOD

Medication-free participants with DSM-IV-defined major depressive disorder (MDD), with (n = 18) and without (n = 41) comorbid DSM-IV anxiety disorders, and healthy volunteers (n = 62) were recruited from October 2006 to May 2010 for mood disorder studies at the New York State Psychiatric Institute. Participants were 18-73 years of age (mean age, 35.8 ± 12.6 years). Depression and anxiety severity was assessed using depression and anxiety subscales from the 17-item Hamilton Depression Rating Scale. Plasma PUFAs eicosapentaenoic acid (EPA; 20:5n-3) and docosahexaenoic acid (DHA; 22:6n-3) and the ratio of arachidonic acid (AA; 22:4n-6) to EPA (AA:EPA) were quantified. This secondary analysis employed analysis of variance with a priori planned contrasts to test for diagnostic group differences in log-transformed PUFA levels (logDHA, logEPA, and logAA:EPA).

RESULTS

Plasma levels of logDHA (F(2,118) = 4.923, P = .009), logEPA (F(2,118) = 6.442, P = .002), and logAA:EPA (F(2,118) = 3.806, P = .025) differed across groups. Participants with MDD had lower logDHA (t(118) = 2.324, P = .022) and logEPA (t(118) = 3.175, P = .002) levels and higher logAA:EPA levels (t(118) = -2.099, P = .038) compared with healthy volunteers. Lower logDHA (t(118) = 2.692, P = .008) and logEPA (t(118) = 2.524, P = .013) levels and higher logAA:EPA levels (t(118) = -2.322, P = .022) distinguished anxious from nonanxious MDD. Depression severity was not associated with PUFA plasma levels; however, anxiety severity across the entire sample correlated negatively with logDHA (r(p) = -0.22, P = .015) and logEPA (r(p) = -0.25, P = .005) levels and positively with logAA:EPA levels (r(p) = 0.18, P = .043).

CONCLUSIONS

The presence and severity of comorbid anxiety were associated with the lowest EPA and DHA levels. Further studies are needed to elucidate whether omega-3 PUFA supplementation may preferentially alleviate MDD with more severe anxiety.

The pharmacologic management of depression in Parkinson's disease

Depression in Parkinson's disease (PD) is common, and it appears to worsen the motor and cognitive progression of the disease, and limits the patient's quality of life. In this paper, we review the pharmacotherapy of depression in people with PD. We find that evidence is sparse when it comes to this patient population. There is some evidence that older tricyclic antidepressants (nortriptyline and desipramine) may be effective in this population. There is also growing evidence that newer antidepressants like paroxetine and venlafaxine may be effective. We will also review a number of other promising medication treatments. What is apparent is the need for more research identifying the most effective medications for treating depression in this population. We provide recommendations that fall in line with current evidence-based practice for managing depression in the general population. Also, we suggest that collaborative models of depression care may be a promising approach to support the identification and effective treatment of those with PD also suffering from depressive disorders.

Omega-3 fatty acids for the treatment of depression: systematic review and meta-analysis

We conducted a meta-analysis of randomized, placebo-controlled trials of omega-3 fatty acid (FA) treatment of major depressive disorder (MDD) in order to determine efficacy and to examine sources of heterogeneity between trials. PubMed (1965-May 2010) was searched for randomized, placebo-controlled trials of omega-3 FAs for MDD. Our primary outcome measure was standardized mean difference in a clinical measure of depression severity. In stratified meta-analysis, we examined the effects of trial duration, trial methodological quality, baseline depression severity, diagnostic indication, dose of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) in omega-3 preparations, and whether omega-3 FA was given as monotherapy or augmentation. In 13 randomized, placebo-controlled trials examining the efficacy of omega-3 FAs involving 731 participants, meta-analysis demonstrated no significant benefit of omega-3 FA treatment compared with placebo (standard mean difference (SMD)=0.11, 95% confidence interval (CI): -0.04, 0.26). Meta-analysis demonstrated significant heterogeneity and publication bias. Nearly all evidence of omega-3 benefit was removed after adjusting for publication bias using the trim-and-fill method (SMD=0.01, 95% CI: -0.13, 0.15). Secondary analyses suggested a trend toward increased efficacy of omega-3 FAs in trials of lower methodological quality, trials of shorter duration, trials which utilized completers rather than intention-to-treat analysis, and trials in which study participants had greater baseline depression severity. Current published trials suggest a small, non-significant benefit of omega-3 FAs for major depression. Nearly all of the treatment efficacy observed in the published literature may be attributable to publication bias.

Application of polyunsaturated fatty acids in internal medicine: beyond the established cardiovascular effects

n-3 Polyunsaturated fatty acids (PUFAs) are organic acids, essential for mammals, whose deficiency is associated with different diseases. The American Heart Association recommends that all adults increase food-derived n-3 PUFA intake and also suggests that patients with documented coronary heart disease consume approximately 1 g of eicosapentaenoic acid and docosahexaenoic acid per day. However, recent evidence broadens their potential application to many other health disorders directly or indirectly associated with cardiovascular disease risk such as rheumatological diseases, mood depression, chronic kidney disease, chronic inflammatory lung diseases and others. These effects seem to be largely dependent on the dosages employed and on the characteristics of the selected patients. The cardiometabolic effects of PUFAs have been largely reviewed elsewhere, so the aim of our review is to point out the potential usefulness of such drugs with pleiotropic effects in the management of the actual typical aging patient, with co-morbidities and multidrug therapies.

Effects of omega 3 fatty acids supplementation in behavior and non-neurodegenerative neuropsychiatric disorders

This work provides a systematic review of all published randomised, controlled clinical trials (RCT) investigating the effects ofn-3 PUFA intake on the prevention and treatment of non-neurodegenerative neuropsychiatric disorders. Five databases (PubMed, EMBASE, LILACS, CINAHL and The Cochrane Database) were searched for RCT in this area published up to April 2011. The selected studies all involved human participants and included a comparison group. Thirty eight studies were identified, which examined the influence ofn-3 PUFA supplementation on the prevention/treatment of depression (non-perinatal) (n23), perinatal depression (n6) and attention deficit hyperactivity disorder (ADHD) (n9). Great heterogeneity was noticed in terms of study design, the doses ofn-3 PUFA administered, and study duration. Some benefit was noted with respect to the treatment of hyperactivity and depression in over half the examined studies, although the evidence was not conclusive. For any firm conclusions to be drawn, further studies will be needed that take into account the initialn-3 PUFA status of the subjects. Excessiven-3 PUFA intakes might be associated with a greater risk of peroxidation events and therefore neuropsychiatric deterioration. Indeed, some studies only recorded benefits when lower doses were administered. It is therefore important that the dose required to achieve any potential benefit be determined.

(N-3) Fatty acids: molecular role and clinical uses in psychiatric disorders

New discoveries in the field of neurophysiology and neuropharmacology have revealed the role of (n-3) fatty acids in controlling inflammation and protecting neuron cells from oxidative damage, preserving their function. It has also been thought that their psychoactive properties could be beneficial in certain psychiatric illnesses. This article discusses the newest discoveries of the affected activities by these fats in the cerebral cortex and the efforts that have been made to put them in practice in clinical trials in humans. In general, we were able to detect certain discord in the scientific community when designing placebo-based studies (mainly in establishing the appropriate therapeutic dose of (n-3) fatty acids, varying from the recommended dietary dose to an amount that may be 3 or 4 times higher), and in interpreting results. Although many studies have had the validity of their results questioned because of their small sample size, several studies seem to indicate that the (n-3) fatty acids are useful therapeutic tools in treating psychiatric conditions such as major depression, bipolar disorder, and several other disorders. Larger sample size studies are still required to better analyze the treatment potential of these agents.

Proximate and fatty acid composition of some commercially important fish species from the Sinop region of the Black Sea

The proximate and fatty acid compositions of the commercially important fish species (Engraulis encrasicolus, Alosa alosa, Belone belone, Scorpaena porcus, Pomatomus saltatrix, Mullus barbatus) from the Sinop region of the Black Sea were examined. The fat contents ranged from 1.26% (for scorpion fish) to 18.12% (for shad). The protein contents were min 14.54% (for red mullet) and maximum 20.26% (for belone). The fatty acid compositions of the fish ranged from 27.83 to 35.91% for saturated fatty acids, 19.50-33.80% for monounsaturated fatty acids and 15.25-40.02% for polyunsaturated fatty acids. Among the saturated fatty acids, palmitic acid (16:0) (17.75-22.20%) was the dominant fatty acid for all the fish species. As a second saturated fatty acid, myristic acid (14:0) was observed in four of the fish species and its content ranged from 4.72 to 7.31%. Whereas, for the other two fish species, the second saturated fatty acid was stearic acid (18:0) ranging between 4.54 and 10.64%. Among the monounsaturated fatty acids, those occurring in the highest proportions were oleic acid (18:1n-9c) (11.67-22.45%) and palmitoleic acid (16:1) (4.50-9.40%). Docosahexaenoic acid (22:6n-3) (5.41-28.52%), eicosapentaenoic acid (20:5n-3) (4.68-11.06) and linoleic acid (18:2n-6) (1.38-3.49%) were dominant polyunsaturated fatty acids, respectively. All the species, in particular the belone, the anchovy and the shad had high levels of the n-3 series.

Meta-analysis of the effects of eicosapentaenoic acid (EPA) in clinical trials in depression

OBJECTIVE

Randomized trials of omega-3 polyunsaturated fatty acid (PUFA) treatment for depression have differed in outcome. Recent meta-analyses ascribe discrepancies to differential effects of eicosapentaenoic acid (EPA) versus docosahexaenoic acid (DHA) and to diagnostic heterogeneity. This meta-analysis tests the hypothesis that EPA is the effective component in PUFA treatment of major depressive episodes.

DATA SOURCES

PubMed/MeSH was searched for studies published in English from 1960 through June 2010 using the terms fish oils (MeSH) AND (depressive disorder [MeSH] OR bipolar depression) AND randomized controlled trial (publication type). The search was supplemented by manual bibliography review and examination of relevant review articles.

STUDY SELECTION

The search yielded 15 trials involving 916 participants. Studies were included if they had a prospective, randomized, double-blinded, placebo-controlled study design; if depressive episode was the primary complaint (with or without comorbid medical conditions); if omega-3 PUFA supplements were administered; and if appropriate outcome measures were used to assess depressed mood.

DATA EXTRACTION

Extracted data included study design, sample sizes, doses and percentages of EPA and DHA, mean ages, baseline and endpoint depression ratings and standard deviations for PUFA and placebo groups, and P values. The clinical outcome of interest was the standardized mean difference in the change from baseline to endpoint scores on a depression rating scale in subjects taking PUFA supplements versus subjects taking placebo.

DATA SYNTHESIS

In a mixed-effect model, percentage of EPA in the supplements was the fixed-effect predictor, dichotomized into 2 groups: EPA < 60% or EPA ≥ 60% of the total EPA + DHA. Secondary analyses explored the relevance of treatment duration, age, and EPA dose.

RESULTS

Supplements with EPA ≥ 60% showed benefit on standardized mean depression scores (effect size = 0.532; 95% CI, 0.277-0.733; t = 4.195; P < .001) versus supplements with EPA < 60% (effect size = -0.026; 95% CI, -0.200 to 0.148; t = -0.316; P = .756), with negligible contribution of random effects or heteroscedasticity and with no effects of treatment duration or age. Supplements with EPA < 60% were ineffective. Exploratory analyses supported a nonlinear model, with improvement determined by the dose of EPA in excess of DHA, within the range of 200 to 2,200 mg/d of EPA.

CONCLUSIONS

Supplements containing EPA ≥ 60% of total EPA + DHA, in a dose range of 200 to 2,200 mg/d of EPA in excess of DHA, were effective against primary depression. Translational studies are needed to determine the mechanisms of EPA's therapeutic benefit.

The promise of neuroprotective agents in Parkinson's disease

Parkinson’s disease (PD) is characterized by loss of dopamine neurons in the substantia nigra of the brain. Since there are limited treatment options for PD, neuroprotective agents are currently being tested as a means to slow disease progression. Agents targeting oxidative stress, mitochondrial dysfunction, and inflammation are prime candidates for neuroprotection. This review identifies Rasagiline, Minocycline, and creatine, as the most promising neuroprotective agents for PD, and they are all currently in phase III trials. Other agents possessing protective characteristics in delaying PD include stimulants, vitamins, supplements, and other drugs. Additionally, combination therapies also show benefits in slowing PD progression. The identification of neuroprotective agents for PD provides us with therapeutic opportunities for modifying the course of disease progression and, perhaps, reducing the risk of onset when preclinical biomarkers become available.

Cognitive-behavioral therapy for depression in Parkinson's disease: a randomized, controlled trial

OBJECTIVE

Despite the negative effects of depression in Parkinson's disease, there is currently no evidence-based standard of care. The purpose of this study was to examine the efficacy of individually administered cognitive-behavioral therapy (CBT), relative to clinical monitoring (with no new treatment), for depression in this medical population.

METHOD

Eighty depressed (based on DSM-IV criteria) patients with Parkinson's disease participated in a randomized, controlled trial of CBT relative to clinical monitoring (1:1 ratio) in an academic medical center from April 2007 to July 2010. All patients continued to maintain stable medication regimens under the care of their personal physicians. The 17-item Hamilton Depression Rating Scale (HAM-D) total score was the primary outcome. CBT was modified to meet the unique needs of the Parkinson's disease population and provided for 10 weeks. Assessments were completed by blind raters at baseline and 5 (midpoint), 10 (end of treatment), and 14 weeks (follow-up evaluation) postrandomization.

RESULTS

The CBT group reported greater reductions in depression (change in HAM-D score) than the clinical monitoring group. At week 10, the mean HAM-D score change was 7.35 for CBT relative to 0.05 for clinical monitoring. CBT was also superior to clinical monitoring on several secondary outcomes (i.e., Beck Depression Inventory scores, anxiety, quality of life, coping, Parkinson's disease symptom ratings). There were more treatment responders in the CBT group than the clinical monitoring group (56% versus 8%, respectively).

CONCLUSIONS

CBT may be a viable approach for the treatment of depression in Parkinson's disease. Further research is needed to replicate and extend these findings.

The Movement Disorder Society Evidence-Based Medicine Review Update: Treatments for the non-motor symptoms of Parkinson's disease

The Movement Disorder Society (MDS) Task Force on Evidence-Based Medicine (EBM) Review of Treatments for Parkinson's Disease (PD) was first published in 2002 and was updated in 2005 to cover clinical trial data up to January 2004 with the focus on motor symptoms of PD. In this revised version the MDS task force decided it was necessary to extend the review to non-motor symptoms. The objective of this work was to update previous EBM reviews on treatments for PD with a focus on non-motor symptoms. Level-I (randomized controlled trial, RCT) reports of pharmacological and nonpharmacological interventions for the non-motor symptoms of PD, published as full articles in English between January 2002 and December 2010 were reviewed. Criteria for inclusion and ranking followed the original program outline and adhered to EBM methodology. For efficacy conclusions, treatments were designated: efficacious, likely efficacious, unlikely efficacious, non-efficacious, or insufficient evidence. Safety data were catalogued and reviewed. Based on the combined efficacy and safety assessment, Implications for clinical practice were determined using the following designations: clinically useful, possibly useful, investigational, unlikely useful, and not useful. Fifty-four new studies qualified for efficacy review while several other studies covered safety issues. Updated and new efficacy conclusions were made for all indications. The treatments that are efficacious for the management of the different non-motor symptoms are as follows: pramipexole for the treatment of depressive symptoms, clozapine for the treatment of psychosis, rivastigmine for the treatment of dementia, and botulinum toxin A (BTX-A) and BTX-B as well as glycopyrrolate for the treatment of sialorrhea. The practical implications for these treatments, except for glycopyrrolate, are that they are clinically useful. Since there is insufficient evidence of glycopyrrolate for the treatment of sialorrhea exceeding 1 week, the practice implication is that it is possibly useful. The treatments that are likely efficacious for the management of the different non-motor symptoms are as follows: the tricyclic antidepressants nortriptyline and desipramine for the treatment of depression or depressive symptoms and macrogol for the treatment of constipation. The practice implications for these treatments are possibly useful. For most of the other interventions there is insufficient evidence to make adequate conclusions on their efficacy. This includes the tricyclic antidepressant amitriptyline, all selective serotonin reuptake inhibitors (SSRIs) reviewed (paroxetine, citalopram, sertraline, and fluoxetine), the newer antidepressants atomoxetine and nefazodone, pergolide, Ω-3 fatty acids as well as repetitive transcranial magnetic stimulation (rTMS) for the treatment of depression or depressive symptoms; methylphenidate and modafinil for the treatment of fatigue; amantadine for the treatment of pathological gambling; donepezil, galantamine, and memantine for the treatment of dementia; quetiapine for the treatment of psychosis; fludrocortisone and domperidone for the treatment of orthostatic hypotension; sildenafil for the treatment of erectile dysfunction, ipratropium bromide spray for the treatment of sialorrhea; levodopa/carbidopa controlled release (CR), pergolide, eszopiclone, melatonin 3 to 5 mg and melatonin 50 mg for the treatment of insomnia and modafinil for the treatment of excessive daytime sleepiness. Due to safety issues the practice implication is that pergolide and nefazodone are not useful for the above-mentioned indications. Due to safety issues, olanzapine remains not useful for the treatment of psychosis. As none of the studies exceeded a duration of 6 months, the recommendations given are for the short-term management of the different non-motor symptoms. There were no RCTs that met inclusion criteria for the treatment of anxiety disorders, apathy, medication-related impulse control disorders and related behaviors other than pathological gambling, rapid eye movement (REM) sleep behavior disorder (RBD), sweating, or urinary dysfunction. Therefore, there is insufficient evidence for the treatment of these indications. This EBM review of interventions for the non-motor symptoms of PD updates the field, but, because several RCTs are ongoing, a continual updating process is needed. Several interventions and indications still lack good quality evidence, and these gaps offer an opportunity for ongoing research. © 2011 Movement Disorder Society.

Impact of ω-3 fatty acids in Parkinson's disease

Current epidemiological, preclinical and clinical data suggest that omega-3 polyunsaturated fatty acids (n-3 PUFAs) may constitute therapeutic strategy for several disorders of the central nervous system, including Parkinson's disease (PD). PD is a neurodegenerative disorder primarily characterized by motor symptoms but which also includes several other pathological features such as autonomic system failures, mood disorders, and cognitive deficits. Current pharmacological options for the disease are limited to symptom management and their long-term use leads to important side effects. In this review, we discuss the evidence for the effects of n-3 PUFAs in PD both from an epidemiological perspective as well as in light of data gathered on various pathological features of the disease. Effects of n-3 PUFAs on the dopaminergic system, α-synucleinopathy, their possible mechanisms of action as well as their therapeutic potential for PD patients are also reviewed. n-3 PUFAs are inexpensive, readily transferable to the clinical setting and their use could represent a neuroprotective strategy or a disease-modifying option to delay the appearance of symptoms. It could also be beneficial as a symptomatologic treatment or serve as an add-on therapy to current pharmacological approaches. Review of the current literature as well as the undertaking of future clinical trials will shed light on these possibilities.

The role of 5-HT₁A receptors in fish oil-mediated increased BDNF expression in the rat hippocampus and cortex: a possible antidepressant mechanism

Epidemiological and dietary studies show that nutritional deficit of omega-3 polyunsaturated fatty acids (ω-3 PUFA) is directly related to the prevalence and severity of depression. Supplementation with docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA) during critical periods of development (pregnancy and lactation) is essential for cortical maturation, synaptogenesis and myelination, and may also mitigate the risk for cognitive deficits and psychopathologies in young adults. The present study was performed to evaluate the involvement of serotonin (5-HT) receptors, particularly of 5-HT(1A), and hippocampal brain-derived neurotrophic factor (BDNF) expression in the antidepressant effect of ω-3 PUFA supplementation. In Experiment 1, the antidepressant effects of fish oil were assessed by the modified forced swim test in adult rats. The data indicated a robust antidepressant effect produced by this supplementation and that treatment of the rats with WAY 100135 reversed this effect. In Experiment 2, cortical and hippocampal contents of BDNF, 5-HT, dopamine (DA) and its metabolites, 5-hydroxyindoleacetic acid (5-HIAA), and 3,4-dihydroxyphenylacetic acid (DOPAC), were determined in animals subjected to the same protocol. Increased BDNF expression in the cortex and hippocampus of both age groups was detected. In 90 day-old rats, 5-HT content in the hippocampus was increased, whereas 5-HIAA formation was diminished in the fish oil group. We suggest the occurrence of a reciprocal involvement of 5-HT(1A) receptors activation and the hippocampal BDNF-increased expression mediated by fish oil supplementation. These data corroborate and expand the notion that supplementation with ω-3 PUFA produces antidepressant effects mediated by an increase in serotonergic neurotransmission, particularly in the hippocampus. This article is part of a Special Issue entitled 'Anxiety and Depression'.

Altered cholesterol and fatty acid metabolism in Huntington disease

Huntington disease is an autosomal dominant neurodegenerative disorder characterized by behavioral abnormalities, cognitive decline, and involuntary movements that lead to a progressive decline in functional capacity, independence, and ultimately death. The pathophysiology of Huntington disease is linked to an expanded trinucleotide repeat of cytosine-adenine-guanine (CAG) in the IT-15 gene on chromosome 4. There is no disease-modifying treatment for Huntington disease, and novel pathophysiological insights and therapeutic strategies are needed. Lipids are vital to the health of the central nervous system, and research in animals and humans has revealed that cholesterol metabolism is disrupted in Huntington disease. This lipid dysregulation has been linked to specific actions of the mutant huntingtin on sterol regulatory element binding proteins. This results in lower cholesterol levels in affected areas of the brain with evidence that this depletion is pathologic. Huntington disease is also associated with a pattern of insulin resistance characterized by a catabolic state resulting in weight loss and a lower body mass index than individuals without Huntington disease. Insulin resistance appears to act as a metabolic stressor attending disease progression. The fish-derived omega-3 fatty acids, eicosapentaenoic acid and docosahexaenoic acid, have been examined in clinical trials of Huntington disease patients. Drugs that combat the dysregulated lipid milieu in Huntington disease may help treat this perplexing and catastrophic genetic disease.

Parkinson's disease: the quintessential neuropsychiatric disorder

Although diagnosed by characteristic motor features, Parkinson's disease may be preceded, and is frequently accompanied by, a wide range of cognitive and neuropsychiatric features. In addition to the most commonly studied disorders of dementia, depression, and psychosis, other relatively common and clinically significant psychiatric complications include impulse control disorders, anxiety symptoms, disorders of sleep and wakefulness, and apathy. These problems may be underrecognized and are frequently undertreated. The emergent focus on nonmotor aspects of Parkinson's disease over the past quarter of a century is highlighted by a nonlinear increase in the number of articles published devoted to this topic. Although the development of newer antidepressants, atypical antipsychotics, and cholinesterase inhibitors in recent years has had a positive benefit on the management of these troublesome and distressing symptoms, responses are frequently suboptimal, and this remains an area of major unmet therapeutic need.

N-3 (omega-3) Fatty acids in postpartum depression: implications for prevention and treatment

A growing body of clinical and epidemiological evidence suggests that low dietary intake and/or tissue levels of n-3 (omega-3) polyunsaturated fatty acids (PUFAs) are associated with postpartum depression. Low tissue levels of n-3 PUFAs, particularly docosahexaenoic acid (DHA), are reported in patients with either postpartum or nonpuerperal depression. Moreover, the physiological demands of pregnancy and lactation put childbearing women at particular risk of experiencing a loss of DHA from tissues including the brain, especially in individuals with inadequate dietary n-3 PUFA intake or suboptimal metabolic capabilities. Animal studies indicate that decreased brain DHA in postpartum females leads to several depression-associated neurobiological changes including decreased hippocampal brain-derived neurotrophic factor and augmented hypothalamic-pituitary-adrenal responses to stress. Taken together, these findings support a role for decreased brain n-3 PUFAs in the multifactorial etiology of depression, particularly postpartum depression. These findings, and their implications for research and clinical practice, are discussed.

EPA but not DHA appears to be responsible for the efficacy of omega-3 long chain polyunsaturated fatty acid supplementation in depression: evidence from a meta-analysis of randomized controlled trials

BACKGROUND

Epidemiologic and case-control data suggest that increased dietary intake of omega-3 long-chain polyunsaturated fatty acids (omega3 LC-PUFAs) may be of benefit in depression. However, the results of randomized controlled trials are mixed and controversy exists as to whether either eicosapentaenoic acid (EPA) or docosahexaenoic acid (DHA) or both are responsible for the reported benefits.

OBJECTIVE

The aim of the current study was to provide an updated meta-analysis of all double-blind, placebo-controlled, randomized controlled trials examining the effect of omega3 LC-PUFA supplementation in which depressive symptoms were a reported outcome. The study also aimed to specifically test the differential effectiveness of EPA versus DHA through meta-regression and subgroup analyses.

DESIGN

Studies were selected using the PubMed database on the basis of the following criteria: (1) randomized design; (2) placebo controlled; (3) use of an omega3 LC-PUFA preparation containing DHA, EPA, or both where the relative amounts of each fatty acid could be quantified; and (4) reporting sufficient statistics on scores of a recognizable measure of depressive symptoms.

RESULTS

Two hundred forty-one studies were identified, of which 28 met the above inclusion criteria and were therefore included in the subsequent meta-analysis. Using a random effects model, overall standardized mean depression scores were reduced in response to omega3 LC-PUFA supplementation as compared with placebo (standardized mean difference = -0.291, 95% CI = -0.463 to -0.120, z = -3.327, p = 0.001). However, significant heterogeneity and evidence of publication bias were present. Meta-regression studies showed a significant effect of higher levels of baseline depression and lower supplement DHAEPA ratio on therapeutic efficacy. Subgroup analyses showed significant effects for: (1) diagnostic category (bipolar disorder and major depression showing significant improvement with omega3 LC-PUFA supplementation versus mild-to-moderate depression, chronic fatigue and non-clinical populations not showing significant improvement); (2) therapeutic as opposed to preventive intervention; (3) adjunctive treatment as opposed to monotherapy; and (4) supplement type. Symptoms of depression were not significantly reduced in 3 studies using pure DHA (standardized mean difference 0.001, 95% CI -0.330 to 0.332, z = 0.004, p = 0.997) or in 4 studies using supplements containing greater than 50% DHA (standardized mean difference = 0.141, 95% CI = -0.195 to 0.477, z = 0.821, p = 0.417). In contrast, symptoms of depression were significantly reduced in 13 studies using supplements containing greater than 50% EPA (standardized mean difference = -0.446, 95% CI = -0.753 to -0.138, z = -2.843, p = 0.005) and in 8 studies using pure ethyl-EPA (standardized mean difference = -0.396, 95% CI = -0.650 to -0.141, z = -3.051, p = 0.002). However, further meta-regression studies showed significant inverse associations between efficacy and study methodological quality, study sample size, and duration, thus limiting the confidence of these findings.

CONCLUSIONS

The current meta-analysis provides evidence that EPA may be more efficacious than DHA in treating depression. However, owing to the identified limitations of the included studies, larger, well-designed, randomized controlled trials of sufficient duration are needed to confirm these findings.

A meta-analytic review of polyunsaturated fatty acid compositions in patients with depression

BACKGROUND

On the basis of evidence from studies showing the antidepressant effects of omega-3 polyunsaturated fatty acids and the inverse relation between fish consumption and the prevalence of depression, the phospholipid hypothesis seems promising in ascertaining the etiology and treatment of depression. Although several studies have shown lower levels of omega-3 (n-3) polyunsaturated fatty acids in depressive patients, the results of individual polyunsaturated fatty acids, including docosahexaenoic acid (DHA), eicosapentaenoic acid (EPA), and the omega-6 (n-6) polyunsaturated fatty acid arachidonic acid (AA), were inconsistent.

METHODS

We conducted the meta-analyses of 14 studies comparing the levels of polyunsaturated fatty acids between depressive patients and control subjects. The effect size of each study was synthesized by using a random effects model.

RESULTS

Compared with control subjects, the levels of EPA, DHA, and total n-3 polyunsaturated fatty acids were significantly lower in depressive patients. There was no significant change in AA or total n-6 polyunsaturated fatty acids.

CONCLUSIONS

The results showed lower levels of EPA, DHA, and total n-3 polyunsaturated fatty acids in patients with depression, thus implying that n-3 polyunsaturated fatty acids play a role in the pathogenesis of depression. Our findings provide further support to the phospholipid hypothesis of depression and a rationale for using n-3 polyunsaturated fatty acids as an alternative treatment for depression. With these results, future studies examining specific roles of DHA and EPA in different clusters of depressive symptoms are warranted.

Updated systematic review and meta-analysis of the effects of n-3 long-chain polyunsaturated fatty acids on depressed mood

BACKGROUND

The debate over a role for n-3 long-chain polyunsaturated fatty acids (n-3 PUFAs) in depressed mood continues.

OBJECTIVE

The objective was to update a previous systematic review and meta-analysis of published randomized controlled trials investigating the effects of n-3 PUFAs on depressed mood and to explore potential sources of heterogeneity.

DESIGN

Eight databases were searched for trials that randomly assigned participants to receive n-3 PUFAs/fish, measured depressed mood, used human participants, and included a comparison group up to April 2009.

RESULTS

Thirty-five randomized controlled trials were identified; 17 were not included in the previous review. The pooled standardized difference in mean outcome of the 29 trials that provided data to allow pooling (fixed-effects model) was 0.10 SD (95% CI: 0.02, 0.17) in those who received n-3 PUFAs compared with placebo, with strong evidence of heterogeneity (I(2) = 65%, P < 0.01). The presence of funnel plot asymmetry suggested that publication bias was a likely source of this heterogeneity. Depressive symptom severity and participant diagnosis also explained some of the observed heterogeneity. Greater effects of n-3 PUFAs were found in individuals with more-severe depressive symptoms. In trials that enrolled individuals with a diagnosed depressive disorder, the combined mean difference was 0.41 (95% CI: 0.26, 0.55), although evidence of heterogeneity was also found (I(2) = 71%). In trials that enrolled individuals without a depressive diagnosis, no beneficial effects of n-3 PUFAs were found (largest combined mean difference: 0.22; 95% CI: -0.01, 0.44; I(2) = 0%).

CONCLUSIONS

Trial evidence of the effects of n-3 PUFAs on depressed mood has increased but remains difficult to summarize because of considerable heterogeneity. The evidence available provides some support of a benefit of n-3 PUFAs in individuals with diagnosed depressive illness but no evidence of any benefit in individuals without a diagnosis of depressive illness.

Neuropsychiatric symptoms in Parkinson's disease

Neuropsychiatric symptoms are common in Parkinson's disease, even at the earliest stages, and have important consequences for quality of life and daily functioning, are associated with increased carer burden and increased risk for nursing home admission. In addition to cognitive impairment, a wide range of neuropsychiatric symptoms have been reported. In this article, the epidemiology, clinical course, diagnosis, and management of some of the most common neuropsychiatric symptoms in PD are discussed: depression, anxiety, apathy, fatigue, and psychotic symptoms. Although much is known regarding the prevalence and course of these symptoms, the empirical evidence for how to manage these symptoms is limited at best. There is thus an urgent need for systematic studies for the pharmacological and non-pharmacological management of these symptoms.

Modulation of brain-derived neurotrophic factor as a potential neuroprotective mechanism of action of omega-3 fatty acids in a parkinsonian animal model

While we recently reported the beneficial effects of omega-3 polyunsaturated fatty acids (n-3 PUFAs) in a mouse model of Parkinson's disease (PD), the mechanisms of action remain largely unknown. Here, we specifically investigated the contribution of the brain-derived neurotrophic factor (BDNF) to the neuroprotective effect of n-3 PUFA observed in a mouse model of PD generated by a subacute exposure to MPTP using a total of 7 doses of 20mg/kg over 5 days. The ten-month high n-3 PUFA treatment which preceded the MPTP exposure induced an increase of BDNF mRNA expression in the striatum, but not in the motor cortex of animals fed the high n-3 PUFA diet. In contrast, n-3 PUFA treatment increased BDNF protein levels in the motor cortex of MPTP-treated mice, an effect not observed in vehicle-treated mice. The mRNA expression of the high-affinity BDNF receptor tropomyosin-related kinase B (TrkB) was increased in the striatum of MPTP-treated mice fed the high n-3 PUFA diet compared to vehicle and MPTP-treated mice on the control diet and to vehicle mice on the high n-3 PUFA diet. These data suggest that the modulation of BDNF expression contributes, in part, to n-3 PUFA-induced neuroprotection in an animal model of PD.

You are what you eat: of fish, fat and folate in late-life psychiatric disorders

PURPOSE OF REVIEW

There has been increasing research into the role of nutritional factors in mood and cognitive disorders in later life. This review evaluates findings from recent research for the role and effect of n-3 polyunsaturated fatty acids (PUFAs) and B vitamins in mood and cognitive disorders in later life.

RECENT FINDINGS

Epidemiological studies, including genetic epidemiological ones, continue to provide support for the role of folate and/or vitamin B12 in mood disorders in later life. However, evidence from recent randomized controlled trials for the effect of these B vitamins and n-3 PUFAs is modest. There is little robust evidence for the effect of these nutrients on cognitive disorders in later life.

SUMMARY

Larger randomized controlled trials allowing more appropriate meta-analyses are required to further evaluate current findings. Additionally, methods derived from research in geriatric medicine may assist in conceptualizing a role for these nutrients.

Neuropsychiatry of Parkinson's disease

Parkinson's disease (PD) is traditionally regarded as a movement disorder. In recent years, however, non-motor symptoms have been considered significant factors of disability at all stages of the illness. Behavioral and psychological symptoms or neuropsychiatric syndromes associated with PD are frequent and may represent a challenge in the management of these patients. They include anxiety, depression, psychosis, sleep, sexual and impulse control disorders, apathy and cognitive dysfunction. Their pathogenesis in PD is complex, involving neurodegenerative, drug-related and psychological mechanisms. We will review the current knowledge of this growing field, also focusing on the management of theses syndromes.

Emerging targets for antidepressant therapies

Despite adequate antidepressant monotherapy, the majority of depressed patients do not achieve remission. Even optimal and aggressive therapy leads to a substantial number of patients who show minimal and often only transient improvement. In order to address this substantial problem of treatment-resistant depression, a number of novel targets for antidepressant therapy have emerged as a consequence of major advances in the neurobiology of depression. Three major approaches to uncover novel therapeutic interventions are: first, optimizing the modulation of monoaminergic neurotransmission; second, developing medications that act upon neurotransmitter systems other than monoaminergic circuits; and third, using focal brain stimulation to directly modulate neuronal activity. We review the most recent data on novel therapeutic compounds and their antidepressant potential. These include triple monoamine reuptake inhibitors, atypical antipsychotic augmentation, and dopamine receptor agonists. Compounds affecting extra-monoamine neurotransmitter systems include CRF(1) receptor antagonists, glucocorticoid receptor antagonists, substance P receptor antagonists, NMDA receptor antagonists, nemifitide, omega-3 fatty acids, and melatonin receptor agonists. Focal brain stimulation therapies include vagus nerve stimulation (VNS), transcranial magnetic stimulation (TMS), magnetic seizure therapy (MST), transcranial direct current stimulation (tDCS), and deep brain stimulation (DBS).