Polyunsaturated fatty acid supplementation for schizophrenia

Adjunctive agents to antipsychotics in schizophrenia: a systematic umbrella review and recommendations for amino acids, hormonal therapies and anti-inflammatory drugs

QUESTION

This umbrella review and guidelines aimed to provide evidence to support the rational choice of selected adjunctive therapies for schizophrenia.

STUDY SELECTION AND ANALYSIS

Following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) and World Federation of Societies of Biological Psychiatry (WFSBP)-grading recommendations, 63 randomised control trials (RCTs) (of which 4219 unique participants have completed the RCTs) and 29 meta-analyses were analysed.

FINDINGS

Provisional recommendations (WFSBP-grade 1) could be made for two molecules in augmentation to antipsychotics: (1) N-acetyl-cysteine (NAC, 1200-3600 mg/day, for >12 consecutive weeks) in improving negative symptoms, general psychopathology (positive and negative syndrome scale for schizophrenia (PANSS) general psychopathology factor (G)-G subscale), with the RCTs with the longer duration showing the most robust findings; (2) polyunsaturated fatty acids (3000 mg/day of eicosapentaenoic acid, for >12 weeks) in improving general psychopathology. Weaker recommendations (ie, WFSBP-grade 2) could be drawn for sarcosine (2 g/day) and minocycline (200-300 mg/day) for improving negative symptoms in chronic schizophrenia (not early schizophrenia), and NAC for improving positive symptoms and cognition. Weak recommendations are not ready for clinical practice. There is provisional evidence that oestrogens and raloxifene are effective in some patients, but further research is needed to determine their benefit/risk ratio.

CONCLUSIONS

The results of this umbrella review should be interpreted with caution as the number of RCTs included in the meta-analyses was generally small and the effect sizes were weak or medium. For NAC, two RCTs with low risk of bias have provided conflicting results and the WFSBP-grade recommendation included also the results of meta-analyses. These drugs could be provisionally prescribed for patients for whom no other treatments have been effective, but they should be discontinued if they prove ineffective.

Integrative Nursing: A Framework for Whole-Person Mental Health Care

The incidence of mental illness continues to increase since the start of the COVID-19 pandemic (Mental Health America, 2022). Demand for mental health services has grown, and providers report being "unable to meet the demand" or having an increase in wait times for access to care (American Psychological Association, 2022, para. 1). Due to this increase in demand, more patients are seeking mental health care from their primary care providers. Over the past decade, integrative models of care have been expanding into mental health care (Lake, 2017). Integrative Nursing is a strategy for improving the quality of care provided to patients seeking care for mental health diagnoses, as well as those with a goal of increasing mental health and wellbeing. This article proposes that Integrative Nursing can serve as a framework for providing whole-person mental health care.

The Role of D-Serine and D-Aspartate in the Pathogenesis and Therapy of Treatment-Resistant Schizophrenia

Schizophrenia (Sch) is a severe and widespread mental disorder. Antipsychotics (APs) of the first and new generations as the first-line treatment of Sch are not effective in about a third of cases and are also unable to treat negative symptoms and cognitive deficits of schizophrenics. This explains the search for new therapeutic strategies for a disease-modifying therapy for treatment-resistant Sch (TRS). Biological compounds are of great interest to researchers and clinicians, among which D-Serine (D-Ser) and D-Aspartate (D-Asp) are among the promising ones. The Sch glutamate theory suggests that neurotransmission dysfunction caused by glutamate N-methyl-D-aspartate receptors (NMDARs) may represent a primary deficiency in this mental disorder and play an important role in the development of TRS. D-Ser and D-Asp are direct NMDAR agonists and may be involved in modulating the functional activity of dopaminergic neurons. This narrative review demonstrates both the biological role of D-Ser and D-Asp in the normal functioning of the central nervous system (CNS) and in the pathogenesis of Sch and TRS. Particular attention is paid to D-Ser and D-Asp as promising components of a nutritive disease-modifying therapy for TRS.

Evidence for Altered Phosphoinositide Signaling-Associated Molecules in the Postmortem Prefrontal Cortex of Patients with Schizophrenia

Phosphoinositides (PIs) play important roles in the structure and function of the brain. Associations between PIs and the pathophysiology of schizophrenia have been studied. However, the significance of the PI metabolic pathway in the pathology of schizophrenia is unknown. We examined the expression of PI signaling-associated proteins in the postmortem brain of schizophrenia patients. Protein expression levels of phosphatidylinositol 4-phosphate 5-kinase type-1 gamma (PIP5K1C), phosphatidylinositol 4-kinase alpha (PIK4CA, also known as PIK4A), phosphatase and tensin homolog deleted from chromosome 10 (PTEN), protein kinase B (Akt), and glycogen synthase kinase 3β (GSK3β) were measured using enzyme-linked immunosorbent assays and multiplex fluorescent bead-based immunoassays of the prefrontal cortex (PFC) of postmortem samples from 23 schizophrenia patients and 47 normal controls. We also examined the association between PIK4CA expression and its genetic variants in the same brain samples. PIK4CA expression was lower, whereas Akt expression was higher, in the PFC of schizophrenia patients than in that of controls; PIP5K1C, PTEN, and GSK3β expression was not different. No single-nucleotide polymorphism significantly affected protein expression. We identified molecules involved in the pathology of schizophrenia via this lipid metabolic pathway. These results suggest that PIK4CA is involved in the mechanism underlying the pathogenesis of schizophrenia and is a potential novel therapeutic target.

Beneficial Outcomes of Omega-6 and Omega-3 Polyunsaturated Fatty Acids on Human Health: An Update for 2021

Oxidative stress and inflammation have been recognized as important contributors to the risk of chronic non-communicable diseases. Polyunsaturated fatty acids (PUFAs) may regulate the antioxidant signaling pathway and modulate inflammatory processes. They also influence hepatic lipid metabolism and physiological responses of other organs, including the heart. Longitudinal prospective cohort studies demonstrate that there is an association between moderate intake of the omega-6 PUFA linoleic acid and lower risk of cardiovascular diseases (CVDs), most likely as a result of lower blood cholesterol concentration. Current evidence suggests that increasing intake of arachidonic acid (up to 1500 mg/day) has no adverse effect on platelet aggregation and blood clotting, immune function and markers of inflammation, but may benefit muscle and cognitive performance. Many studies show that higher intakes of omega-3 PUFAs, especially eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), are associated with a lower incidence of chronic diseases characterized by elevated inflammation, including CVDs. This is because of the multiple molecular and cellular actions of EPA and DHA. Intervention trials using EPA + DHA indicate benefit on CVD mortality and a significant inverse linear dose-response relationship has been found between EPA + DHA intake and CVD outcomes. In addition to their antioxidant and anti-inflammatory roles, omega-3 fatty acids are considered to regulate platelet homeostasis and lower risk of thrombosis, which together indicate their potential use in COVID-19 therapy.

Beneficial effects of omega-3 fatty acid supplementation in schizophrenia: possible mechanisms

BACKGROUND

Schizophrenia is a serious long-term psychotic disorder marked by positive and negative symptoms, severe behavioral problems and cognitive function deficits. The cause of this disorder is not completely clear, but is suggested to be multifactorial, involving both inherited and environmental factors. Since human brain regulates all behaviour, studies have focused on identifying changes in neurobiology and biochemistry of brain in schizophrenia. Brain is the most lipid rich organ (approximately 50% of brain dry weight). Total brain lipids is constituted of more than 60% of phospholipids, in which docosahexaenoic acid (DHA, 22:6n-3) is the most abundant (more than 40%) polyunsaturated fatty acid (PUFA) in brain membrane phospholipids. Results from numerous studies have shown significant decreases of PUFAs, in particular, DHA in peripheral blood (plasma and erythrocyte membranes) as well as brain of schizophrenia patients at different developmental phases of the disorder. PUFA deficiency has been associated to psychotic symptoms and cognitive deficits in schizophrenia. These findings have led to a number of clinical trials examining whether dietary omega-3 fatty acid supplementation could improve the course of illness in patients with schizophrenia. Results are inconsistent. Some report beneficial whereas others show not effective. The discrepancy can be attributed to the heterogeneity of patient population.

METHODS

In this review, results from recent experimental and clinical studies, which focus on illustrating the role of PUFAs in the development of schizophrenia were examined. The rationale why omega-3 supplementation was beneficial on symptoms (presented by subscales of the positive and negative symptom scale (PANSS), and cognitive functions in certain patients but not others was reviewed. The potential mechanisms underlying the beneficial effects were discussed.

RESULTS

Omega-3 fatty acid supplementation reduced the conversion rate to psychosis and improved both positive and negative symptoms and global functions in adolescents at ultra-high risk for psychosis. Omega-3 fatty acid supplementation could also improve negative symptoms and global functions in the first-episode patients with schizophrenia, but improve mainly total or general PANSS subscales in chronic patients. Patients with low PUFA (particularly DHA) baseline in blood were more responsive to the omega-3 fatty acid intervention.

CONCLUSION

Omega-3 supplementation is more effective in reducing psychotic symptom severity in young adults or adolescents in the prodromal phase of schizophrenia who have low omega-3 baseline. Omega-3 supplementation was more effective in patients with low PUFA baseline. It suggests that patients with predefined lipid levels might benefit from lipid treatments, but more controlled clinical trials are warranted.

Polyunsaturated Fatty Acids: What is Their Role in Treatment of Psychiatric Disorders?

In the central nervous system omega-3 fatty acids modulate cell signaling and affect dopaminergic and serotonergic pathways. On this basis, a new application for omega-3 fatty acids has been proposed, concerning the treatment of several psychiatric disorders. The present article is an update of a previous systematic review and is aimed to provide a complete report of data published in the period between 1980 and 2019 on efficacy and tolerability of omega-3 fatty acids in psychiatric disorders. In July 2019, an electronic search on PUBMED, Medline and PsychINFO of all RCTs, systematic reviews and meta-analyses on omega-3 fatty acids and psychiatric disorders without any filter or MESH restriction was performed. After eligibility processes, the final number of records included in this review was 126. One hundred and two of these studies were RCTs, while 24 were reviews and meta-analyses. The role of omega-3 fatty acids was studied in schizophrenia, major depression, bipolar disorder, anxiety disorders, obsessive-compulsive disorder, post-traumatic stress disorder, attention deficit hyperactivity disorder (ADHD), autism spectrum disorders, eating disorders, substance use disorder and borderline personality disorder. The main evidence of the efficacy of omega-3 fatty acids has been obtained in treating depressive symptoms in patients with major depression and, to a lesser degree, bipolar depression. Some efficacy was also found in early phases of schizophrenia in addition to antipsychotic treatment, but not in the chronic phases of psychosis. Small beneficial effects of omega-3 fatty acids were observed in ADHD and positive results were reported in a few trials on core symptoms of borderline personality disorder. For other psychiatric disorders results are inconsistent.

Trim the fat: the role of omega-3 fatty acids in psychopharmacology

The American Psychiatric Association (APA) currently recommends the use of omega-3 fatty acid supplementation for depressive disorders, impulse-control disorders, and psychotic disorders in treatment guidelines. This review examines the evidence for efficacy of omega-3 fatty acids in depressive disorders, bipolar disorder, anxiety disorders, post-traumatic stress disorder (PTSD), and psychosis. Meta-analysis of randomized-controlled trials of omega-3 fatty acids for depression are inconclusive, with strong evidence of publication bias, sizable heterogeneity between included studies, and substantial methodological shortcomings in included trials. The large amount of heterogeneity in findings of RCTs of omega-3 fatty acids for unipolar depression is likely attributable to highly heterogeneous sample populations that are given different omega-3 supplements [which differ widely in eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) content, ratio, and dosage] as either adjunctive or monotherapy of other existing treatments, and then measure several different outcomes of depression symptomatology with likely incomplete blinding. Evidence of efficacy of omega-3 supplementation in treating psychosis, PTSD, anxiety, and bipolar mania is minimal. The current guidelines recommending the use of omega-3 fatty acids in adulthood psychiatric conditions should be revisited, especially given several recent negative studies examining the effects of omega-3 fatty acids for cardiovascular disease. Recommending likely ineffective treatment to patients, no matter how benign the side-effect profile, has opportunity cost (e.g. other more effective medications or therapies not being utilized) and likely affects patient compliance with other evidence-based treatments.

Natural Medicines for Psychotic Disorders: A Systematic Review

Patients with psychotic disorders regularly use natural medicines, although it is unclear whether these are effective and safe. The aim of this study was to provide an overview of evidence for improved outcomes by natural medicines. A systematic literature search was performed through Medline, PsycINFO, CINAHL, and Cochrane until May 2015. In 110 randomized controlled trials, evidence was found for glycine, sarcosine, N-acetylcysteine, some Chinese and ayurvedic herbs, ginkgo biloba, estradiol, and vitamin B6 to improve psychotic symptoms when added to antipsychotics. Ginkgo biloba and vitamin B6 seemed to reduce tardive dyskinesia and akathisia. Results on other compounds were negative or inconclusive. All natural agents, except reserpine, were well tolerated. Most study samples were small, study periods were generally short, and most results need replication. However, there is some evidence for beneficial effects of certain natural medicines.

N-3 (Omega-3) Fatty Acids: Effects on Brain Dopamine Systems and Potential Role in the Etiology and Treatment of Neuropsychiatric Disorders

BACKGROUND & OBJECTIVE

A number of neuropsychiatric disorders, including Parkinson's disease, schizophrenia, attention deficit hyperactivity disorder, and, to some extent, depression, involve dysregulation of the brain dopamine systems. The etiology of these diseases is multifactorial, involving genetic and environmental factors. Evidence suggests that inadequate levels of n-3 (omega- 3) polyunsaturated fatty acids (PUFA) in the brain may represent a risk factor for these disorders. These fatty acids, which are derived from the diet, are a major component of neuronal membranes and are of particular importance in brain development and function. Low levels of n-3 PUFAs in the brain affect the brain dopamine systems and, when combined with appropriate genetic and other factors, increase the risk of developing these disorders and/or the severity of the disease. This article reviews the neurobiology of n-3 PUFAs and their effects on dopaminergic function.

CONCLUSION

Clinical studies supporting their role in the etiologies of diseases involving the brain dopamine systems and the potential of n-3 PUFAs in the treatment of these disorders are discussed.

The Role of Omega-3 Fatty Acids in Developmental Psychopathology: A Systematic Review on Early Psychosis, Autism, and ADHD

In this systematic review, we will consider and debate studies that have explored the effects of ω-3 polyunsaturated fatty acids (PUFAs) in three major, and somehow related, developmental psychiatric disorders: Autism, Attention Deficit and Hyperactivity disorder and Psychosis. The impact of ω-3 PUFAs on clinical symptoms and, if possible, brain trajectory in children and adolescents suffering from these illnesses will be reviewed and discussed, considering the biological plausibility of the effects of omega-3 fatty acids, together with their potential perspectives in the field. Heterogeneity in study designs will be discussed in the light of differences in results and interpretation of studies carried out so far.

A Review of Recruitment, Adherence and Drop-Out Rates in Omega-3 Polyunsaturated Fatty Acid Supplementation Trials in Children and Adolescents

INTRODUCTION

The influence of n-3 long-chain polyunsaturated fatty acids (n-3 LCPUFA) supplementation on health outcomes has been studied extensively with randomized controlled trials (RCT). In many research fields, difficulties with recruitment, adherence and high drop-out rates have been reported. However, what is unknown is how common these problems are in n-3 LCPUFA supplementation studies in children and adolescents. Therefore, this paper will review n-3 LCPUFA supplementation studies in children and adolescents with regard to recruitment, adherence and drop-out rates.

METHODS

The Web of Science, PubMed and Ovid databases were searched for papers reporting on RCT supplementing children and adolescents (2-18 years) with a form of n-3 LCPUFA (or placebo) for at least four weeks. As a proxy for abiding to CONSORT guidelines, we noted whether manuscripts provided a flow-chart and provided dates defining the period of recruitment and follow-up.

RESULTS

Ninety manuscripts (reporting on 75 studies) met the inclusion criteria. The majority of the studies did not abide by the CONSORT guidelines: 55% did not provide a flow-chart, while 70% did not provide dates. The majority of studies provided minimal details about the recruitment process. Only 25 of the 75 studies reported an adherence rate which was on average 85%. Sixty-five of the 75 studies included drop-out rates which were on average 17%.

CONCLUSION

Less than half of the included studies abided by the CONSORT guidelines (45% included a flow chart, while 30% reported dates). Problems with recruitment and drop-out seem to be common in n-3 LCPUFA supplementation trials in children and adolescents. However, reporting about recruitment, adherence and dropout rates was very heterogeneous and minimal in the included studies. Some techniques to improve recruitment, adherence and dropout rates were identified from the literature, however these techniques may need to be tailored to n-3 LCPUFA supplementation studies in children and adolescents.

Decreased 16:0/20:4-phosphatidylinositol level in the post-mortem prefrontal cortex of elderly patients with schizophrenia

The etiology of schizophrenia includes phospholipid abnormalities. Phospholipids are bioactive substances essential for brain function. To analyze differences in the quantity and types of phospholipids present in the brain tissue of patients with schizophrenia, we performed a global analysis of phospholipids in multiple brain samples using liquid chromatography electrospray ionization mass/mass spectrometry (LC-ESI/MS/MS) and imaging mass spectrometry (IMS). We found significantly decreased 16:0/20:4-phosphatidylinositol (PI) levels in the prefrontal cortex (PFC) in the brains from patients with schizophrenia in the LC-ESI/MS/MS, and that the 16:0/20:4-PI in grey matter was most prominently diminished according to the IMS experiments. Previous reports investigating PI pathology of schizophrenia did not identify differences in the sn-1 and sn-2 fatty acyl chains. This study is the first to clear the fatty acid composition of PI in brains from patients with schizophrenia. Alteration in the characteristic fatty acid composition of PI may also affect neuronal function, and could play a role in the etiology of schizophrenia. Although further studies are necessary to understand the role of reduced 16:0/20:4-PI levels within the prefrontal cortex in the etiology of schizophrenia, our results provide insight into the development of a novel therapy for the clinical treatment of schizophrenia.

Supplementation with Omega-3 Fatty Acids in Psychiatric Disorders: A Review of Literature Data

A new application for omega-3 fatty acids has recently emerged, concerning the treatment of several mental disorders. This indication is supported by data of neurobiological research, as highly unsaturated fatty acids (HUFAs) are highly concentrated in neural phospholipids and are important components of the neuronal cell membrane. They modulate the mechanisms of brain cell signaling, including the dopaminergic and serotonergic pathways. The aim of this review is to provide a complete and updated account of the empirical evidence of the efficacy and safety that are currently available for omega-3 fatty acids in the treatment of psychiatric disorders. The main evidence for the effectiveness of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) has been obtained in mood disorders, in particular in the treatment of depressive symptoms in unipolar and bipolar depression. There is some evidence to support the use of omega-3 fatty acids in the treatment of conditions characterized by a high level of impulsivity and aggression and borderline personality disorders. In patients with attention deficit hyperactivity disorder, small-to-modest effects of omega-3 HUFAs have been found. The most promising results have been reported by studies using high doses of EPA or the association of omega-3 and omega-6 fatty acids. In schizophrenia, current data are not conclusive and do not allow us either to refuse or support the indication of omega-3 fatty acids. For the remaining psychiatric disturbances, including autism spectrum disorders, anxiety disorders, obsessive-compulsive disorder, eating disorders and substance use disorder, the data are too scarce to draw any conclusion. Concerning tolerability, several studies concluded that omega-3 can be considered safe and well tolerated at doses up to 5 g/day.

Omega-3 fatty acids for the treatment of dementia

BACKGROUND

Omega-3 polyunsaturated fatty acids (omega-3 PUFAs) from fish and plant sources are commonly considered as a promising non-medical alternative to improve brain functions and slow down the progression of dementia. This assumption is mostly based on findings of preclinical studies and epidemiological research. Resulting explanatory models aim at the role omega-3 PUFAs play in the development and integrity of the brain's neurons, their protective antioxidative effect on cell membranes and potential neurochemical mechanisms directly related to Alzheimer-specific pathology. Epidemiological research also found evidence of malnutrition in people with dementia. Considering this and the fact that omega-3 PUFA cannot be synthesised by humans, omega-3 PUFAs might be a promising treatment option for dementia.

OBJECTIVES

To assess the efficacy and safety of omega-3 polyunsaturated fatty acid (PUFA) supplementation for the treatment of people with dementia.

SEARCH METHODS

We searched the Specialized Register of the Cochrane Dementia and Cognitive Improvement Group (ALOIS), MEDLINE, EMBASE, PsycINFO, CINAHL, ClinicalTrials.gov and the World Health Organization (WHO) portal/ICTRP on 10 December 2015. We contacted manufacturers of omega-3 supplements and scanned reference lists of landmark papers and included articles.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) in which omega-3 PUFA in the form of supplements or enriched diets were administered to people with Alzheimer's disease (AD), vascular dementia (VaD), dementia with Lewy bodies (DLB), Parkinson's disease dementia (PDD) or frontotemporal dementia (FTD).

DATA COLLECTION AND ANALYSIS

The primary outcome measures of interest were changes in global and specific cognitive functions, functional performance, dementia severity and adverse effects. Two review authors independently selected studies, extracted data and assessed the quality of trials according to the Cochrane Handbook for Systematic Reviews of Interventions. We rated the quality of the evidence using the GRADE approach. We received unpublished data from the trial authors and collected adverse effects information from the published articles. We conducted meta-analyses for available outcome measures at six months.

MAIN RESULTS

We included three comparable randomised, placebo-controlled trials investigating omega-3 PUFA supplements in 632 participants with mild to moderate AD over six, 12 and 18 months. We found no studies investigating other types of dementia. All trials were of high methodological quality. The overall quality of evidence for most of the outcomes was high.There was no evidence of a benefit from omega-3 PUFAs on cognitive function when measured at six months with the Alzheimer's Disease Assessment Scale - Cognitive subscale (standardised mean difference (SMD) -0.02, 95% confidence interval (CI) -0.19 to 0.15; 566 participants; 3 studies; high quality evidence) or Mini-Mental State Examination (mean difference (MD) 0.18, 95% CI -1.05 to 1.41; 202 participants; 2 studies; high quality evidence) or on activities of daily living (SMD -0.02, 95% CI -0.19 to 0.16; 544 participants; 2 studies; high quality evidence). There was also no effect at six months of treatment on severity of dementia measured with the Clinical Dementia Rating - Sum of Boxes (MD -0.00, 95% CI -0.58 to 0.57; 542 participants; 2 studies; high quality evidence) or on quality of life measured with the Quality of Life Alzheimer's Disease scale (MD -0.10, 95% CI -1.28 to 1.08; 322 participants; 1 study; high quality evidence). There was no difference at six months on mental health measured with the Montgomery-Åsberg Depression Rating Scale (MD -0.10, 95% CI -0.74 to 0.54; 178 participants: 1 study; high quality of evidence) or the Neuropsychiatric Inventory (SMD 0.10, 95% CI -0.07 to 0.27; 543 participants; 2 studies; high quality of evidence). One very small study showed a benefit for omega-3 PUFAs in instrumental activities of daily living after 12 months of treatment (MD -3.50, 95% CI -4.30 to -2.70; 22 participants; moderate quality evidence). The included studies did not measure specific cognitive function. The studies did not report adverse events well. Two studies stated that all adverse events were mild and that they did not differ in overall frequency between omega-3 PUFA and placebo groups. Data from one study showed no difference between groups in frequency of any adverse event (risk ratio (RR) 1.02, 95% CI 0.95 to 1.10; 402 participants; 1 study; moderate quality evidence) or any serious adverse event (RR 1.05, 95% CI 0.78 to 1.41; 402 participants; 1 study; high quality evidence) at 18 months of treatment.

AUTHORS' CONCLUSIONS

We found no convincing evidence for the efficacy of omega-3 PUFA supplements in the treatment of mild to moderate AD. This result was consistent for all outcomes relevant for people with dementia. Adverse effects of omega-3 PUFAs seemed to be low, but based on the evidence synthesised in this review, we cannot make a final statement on tolerability. The effects on other populations remain unclear.

Dietary advice for people with schizophrenia

BACKGROUND

People with serious mental illness have consistently higher levels of mortality and morbidity than the general population. They have greater levels of cardiovascular disease, metabolic disease, diabetes, and respiratory illness. Although genetics may have a role in the physical health problems of these people, lifestyle and environmental factors such as smoking, obesity, poor diet, and low levels of physical activity play a prominent part.

OBJECTIVES

To review the effects of dietary advice for schizophrenia and schizophrenia-like psychosis.

SEARCH METHODS

We searched the Cochrane Schizophrenia Group's Trials Register (September 09, 2013 and February 24, 2016).

SELECTION CRITERIA

We planned to include all randomised clinical trials focusing on dietary advice versus standard care.

DATA COLLECTION AND ANALYSIS

The review authors (RP, KTP) independently screened search results but did not identify any studies that fulfilled the review's criteria.

MAIN RESULTS

We did not identify any studies that met our inclusion criteria.

AUTHORS' CONCLUSIONS

Dietary advice has been shown to improve the dietary intake of the general population. Research is needed to determine whether dietary advice can have a similar benefit in people with serious mental illness.

Levels of Red Blood Cell Fatty Acids in Patients With Psychosis, Their Unaffected Siblings, and Healthy Controls

BACKGROUND

Two recent meta-analyses showed decreased red blood cell (RBC) polyunsaturated fatty acids (FA) in schizophrenia and related disorders. However, both these meta-analyses report considerable heterogeneity, probably related to differences in patient samples between studies. Here, we investigated whether variations in RBC FA are associated with psychosis, and thus may be an intermediate phenotype of the disorder.

METHODS

For the present study, a total of 215 patients (87% outpatients), 187 siblings, and 98 controls were investigated for multiple FA analyses. Based on previous studies, we investigated docosahexaenoic acid (DHA), docosapentaenoic acid (DPA), arachidonic acid (AA), linoleic acid (LA), nervonic acid (NA), and eicasopentaenoic acid (EPA). On an exploratory basis, a large number of additional FA were investigated. Multilevel mixed models were used to compare the FA between the 3 groups.

RESULTS

Compared to controls, both patients and siblings showed significantly increased DHA, DPA, AA, and NA. LA was significantly higher in siblings compared to controls. EPA was not significantly different between the 3 groups. Also the exploratory FA were increased in patients and siblings.

CONCLUSIONS

We found increased RBC FA DHA, DPA, AA, and NA in patients and siblings compared to controls. The direction of change is similar in both patients and siblings, which may suggest a shared environment and/or an intermediate phenotype. Differences between patient samples reflecting stage of disorder, dietary patterns, medication use, and drug abuse are possible modifiers of FA, contributing to the heterogeneity in findings concerning FA in schizophrenia patients.

Omega-3 fatty acids in first-episode schizophrenia - a randomized controlled study of efficacy and relapse prevention (OFFER): rationale, design, and methods

BACKGROUND

Polyunsaturated fatty acid (PUFA) metabolism abnormalities have been long implicated in the etiology of schizophrenia. Although several randomized clinical trials have been carried out to assess the efficacy of omega-3 PUFA as add-on therapy in reducing psychopathology in populations of chronic patients with schizophrenia, only a few concern first-episode schizophrenia. The majority of these studies used a 12-week intervention based on ethyl-eicosapentaenoic acid (ethyl-EPA), however, with conflicting results. An intervention based on docosahexaenoic acid plus EPA has not been used in first-episode schizophrenia studies so far. No add-on supplementation studies have been carried out in medicated first-episode schizophrenia patients to assess the efficacy of omega-3 PUFA in preventing relapses.

METHODS

A randomized placebo-controlled one-center trial will be used to compare the efficacy of 26-week intervention, composed of either 1320 mg/day of EPA and 880 mg/day of DHA, or olive oil placebo with regard to symptom severity and relapse rate in first-episode schizophrenia patients. Eighty-two patients (aged 16-35) will be recruited for the study. Eligible patients will be randomly allocated to one of two intervention arms: an active arm or a placebo arm (olive oil). The primary outcome measure of the clinical evaluation is schizophrenia symptom severity measured by the Positive and Negative Syndrome Scale (PANSS). Other outcomes include depressive symptoms, patient functioning and the level of insight. Correlates of change measured during the study will include structural brain changes, oxidative stress and defense, as well as neuroplasticity indicators. Metabolic syndrome components will also be assessed throughout the study.

DISCUSSION

By comparing 26-week administration of EPA + DHA or (placebo) olive oil as add-on therapy in reducing symptom severity and one-year relapse rate in patients with first episode schizophrenia, it is intended to provide new insights into the efficacy of omega-3 PUFA and correlates of change, and contribute to the improvement of mental health care for individuals suffering from schizophrenia.

TRIAL REGISTRATION

This study has been registered at Clinical Trials.gov with the following number: NCT02210962 .

Effects of oxidative stress on fatty acid- and one-carbon-metabolism in psychiatric and cardiovascular disease comorbidity

OBJECTIVE

Cardiovascular disease (CVD) is the leading cause of death in severe psychiatric disorders (depression, schizophrenia). Here, we provide evidence of how the effects of oxidative stress on fatty acid (FA) and one-carbon (1-C) cycle metabolism, which may initially represent adaptive responses, might underlie comorbidity between CVD and psychiatric disorders.

METHOD

We conducted a literature search and integrated data in a narrative review.

RESULTS

Oxidative stress, mainly generated in mitochondria, is implicated in both psychiatric and cardiovascular pathophysiology. Oxidative stress affects the intrinsically linked FA and 1-C cycle metabolism: FAs decrease in chain length and unsaturation (particularly omega-3 polyunsaturated FAs), and lipid peroxidation products increase; the 1-C cycle shifts from the methylation to transsulfuration pathway (lower folate and higher homocysteine and antioxidant glutathione). Interestingly, corresponding alterations were reported in psychiatric disorders and CVD. Potential mechanisms through which FA and 1-C cycle metabolism may be involved in brain (neurocognition, mood regulation) and cardiovascular system functioning (inflammation, thrombosis) include membrane peroxidizability and fluidity, eicosanoid synthesis, neuroprotection and epigenetics.

CONCLUSION

While oxidative-stress-induced alterations in FA and 1-C metabolism may initially enhance oxidative stress resistance, persisting chronically, they may cause damage possibly underlying (co-occurrence of) psychiatric disorders and CVD. This might have implications for research into diagnosis and (preventive) treatment of (CVD in) psychiatric patients.

Adjunctive use of nonsteroidal anti-inflammatory drugs for schizophrenia: a meta-analytic investigation of randomized controlled trials

OBJECTIVE

To meta-analytically assess the efficacy and tolerability of nonsteroidal anti-inflammatory drugs (NSAIDs) vs placebo in schizophrenia.

METHOD

Searching PubMed, PsycINFO, ISI Web of Science, and the US National Institute of Mental Health clinical trials registry from database inception to December 31, 2012, we conducted a systematic review/meta-analysis of randomized placebo-controlled studies assessing the efficacy of adjunctive NSAIDs. Primary outcome was the change in Positive and Negative Syndrome Scale (PANSS) total score. Secondary outcomes included change in PANSS positive and negative subscores, all-cause discontinuation, and tolerability outcomes. Random effects, pooled, standardized mean changes (Hedges' g) and risk ratios were calculated.

RESULTS

Across 8 studies, including 3 unpublished reports (n = 774), the mean effect size for PANSS total score was -0.236 (95% CI: -0.484 to 0.012, P = .063, I(2) = 60.6%), showing only trend-level superiority for NSAIDs over placebo. The mean effect sizes for the PANSS positive and negative scores were -0.189 (95% CI: -0.373 to -0.005, P = .044) and -0.026 (95% CI: -0.169 to 0.117, P = .72), respectively. The relative risk for all-cause discontinuation was 1.13 (95% CI: 0.794 to 1.599, P = .503). Significant superiority of NSAIDs over placebo regarding PANSS total scores was moderated by aspirin treatment (N = 2, P = .017), inpatient status (N = 4, P = .029), first-episode status (N = 2, P = .048), and (in meta-regression analyses) lower PANSS negative subscores (N = 6, P = .026).

INTERPRETATION

These results indicate that adjunctive NSAIDs for schizophrenia may not benefit patients treated with first-line antipsychotics judged by PANSS total score change. NSAIDs may have benefits for positive symptoms, but the effect was minimal/small. However, due to a limited database, further controlled studies are needed, especially in first-episode patients.

Current approaches to treatments for schizophrenia spectrum disorders, part I: an overview and medical treatments

During the last three decades, an increasing understanding of the etiology, psychopathology, and clinical manifestations of schizophrenia spectrum disorders, in addition to the introduction of second-generation antipsychotics, has optimized the potential for recovery from the illness. Continued development of various models of psychosocial intervention promotes the goal of schizophrenia treatment from one of symptom control and social adaptation to an optimal restoration of functioning and/or recovery. However, it is still questionable whether these new treatment approaches can address the patients' needs for treatment and services and contribute to better patient outcomes. This article provides an overview of different treatment approaches currently used in schizophrenia spectrum disorders to address complex health problems and a wide range of abnormalities and impairments resulting from the illness. There are different treatment strategies and targets for patients at different stages of the illness, ranging from prophylactic antipsychotics and cognitive-behavioral therapy in the premorbid stage to various psychosocial interventions in addition to antipsychotics for relapse prevention and rehabilitation in the later stages of the illness. The use of antipsychotics alone as the main treatment modality may be limited not only in being unable to tackle the frequently occurring negative symptoms and cognitive impairments but also in producing a wide variety of adverse effects to the body or organ functioning. Because of varied pharmacokinetics and treatment responsiveness across agents, the medication regimen should be determined on an individual basis to ensure an optimal effect in its long-term use. This review also highlights that the recent practice guidelines and standards have recommended that a combination of treatment modalities be adopted to meet the complex health needs of people with schizophrenia spectrum disorders. In view of the heterogeneity of the risk factors and the illness progression of individual patients, the use of multifaceted illness management programs consisting of different combinations of physical, psychological, and social interventions might be efficient and effective in improving recovery.

Docosahexaenoic acid, inflammation, and bacterial dysbiosis in relation to periodontal disease, inflammatory bowel disease, and the metabolic syndrome

Docosahexaenoic acid (DHA), a long-chain omega-3 polyunsaturated fatty acid, has been used to treat a range of different conditions, including periodontal disease (PD) and inflammatory bowel disease (IBD). That DHA helps with these oral and gastrointestinal diseases in which inflammation and bacterial dysbiosis play key roles, raises the question of whether DHA may assist in the prevention or treatment of other inflammatory conditions, such as the metabolic syndrome, which have also been linked with inflammation and alterations in normal host microbial populations. Here we review established and investigated associations between DHA, PD, and IBD. We conclude that by beneficially altering cytokine production and macrophage recruitment, the composition of intestinal microbiota and intestinal integrity, lipopolysaccharide- and adipose-induced inflammation, and insulin signaling, DHA may be a key tool in the prevention of metabolic syndrome.

Omega-3 fatty acids for intermittent claudication

BACKGROUND

Omega-3 fatty acids have been used in the treatment and prevention of coronary artery disease although current evidence suggests they may be of limited benefit. Peripheral arterial disease and coronary artery disease share a similar pathogenesis so omega-3 fatty acids may have a similar effect on both conditions. This is an update of a review first published in 2004 and updated in 2007.

OBJECTIVES

To determine the clinical and haematological effects of omega-3 supplementation in people with intermittent claudication.

SEARCH METHODS

For this update the Cochrane Peripheral Vascular Diseases Group Trials Search Co-ordinator searched the Specialised Register (last searched September 2012) and the Cochrane Central Register of Controlled Trials (CENTRAL) (2012, Issue 9).

SELECTION CRITERIA

Randomised controlled trials of omega-3 fatty acids versus placebo or non-omega-3 fatty acids in people with intermittent claudication.

DATA COLLECTION AND ANALYSIS

One review author identified potential trials. Two review authors independently assessed trial quality and extracted data. We contacted study authors for additional information if necessary.

MAIN RESULTS

Nine studies were included representing 425 participants. All studies compared omega-3 fatty acid supplementation with placebo lasting from four weeks to two years. Three studies with long treatment periods administered additional substances, making any observed effects impossible to attribute to omega-3 fatty acids and were excluded from the statistical analyses. One study did not express any mean values and, therefore, could not be included in statistical analyses.No significant differences between intervention and control groups were observed in pain-free walking distance (mean difference (MD) 11.62 m, 95% confidence interval (CI) -67.74 to 90.98), maximal walking distance (MD 16.99 m, 95% CI -72.14 to 106.11), ankle brachial pressure index (MD -0.02, 95% CI -0.09 to 0.05), total cholesterol levels (MD 0.27 mmol/L, 95% CI -0.48 to 1.01), high-density lipoprotein cholesterol levels (MD 0.00 mmol/L, 95% CI -0.16 to 0.15), low-density lipoprotein cholesterol levels (MD 0.44 mmol/L, 95% CI -0.31 to 1.19), triglyceride levels (MD -0.39 mmol/L, 95% CI -1.10 to 0.33), systolic blood pressure (MD 5.00 mmHg, 95% CI -11.59 to 21.59) or plasma viscosity (MD 0.03 mPa/s, 95% CI -0.02 to 0.08).There was some limited evidence that blood but not plasma viscosity levels decreased with treatment and gastrointestinal side effects such as nausea, diarrhoea and flatulence were observed in two studies.

AUTHORS' CONCLUSIONS

Omega-3 fatty acids appear to have little haematological benefit in people with intermittent claudication and there is no evidence of consistently improved clinical outcomes (quality of life, walking distance, ankle brachial pressure index or angiographic findings). Supplementation may also cause adverse effects such as nausea, diarrhoea and flatulence. Further research is needed to evaluate fully short- and long-term effects of omega-3 fatty acids on the most clinically relevant outcomes in people with intermittent claudication before they can be recommended for routine use.

A review of anti-inflammatory agents for symptoms of schizophrenia

Schizophrenia is a chronic debilitating mental disorder that affects about 1% of the US population. The pathophysiology and etiology remain unknown, thus new treatment targets have been challenging and few novel treatments with new mechanisms of action have come to market in the past few decades. Increasing attention has been paid to the role of inflammation in schizophrenia and new data suggests that decreasing inflammation and inflammatory biomarkers may play some role in schizophrenia treatment. This review summarizes the clinical trial literature regarding medications that possess anti-inflammatory properties that have been tested for schizophrenia symptoms and covers such medications as non-steroidal anti-inflammatory agents, such as the cyclo-oxygenase-2 (COX-2) inhibitors and aspirin, omega-3 fatty acids, neurosteroids and minocycline. Overall, there is accumulating evidence, albeit mostly adjunctive treatments, that agents working on inflammatory pathways have some benefits in people with schizophrenia. In the next few years the field will begin to see data on many treatments with anti-inflammatory properties that are currently under study. Hopefully advancements in understanding inflammation and effective treatments having anti-inflammatory properties may help revolutionize our understanding and provide new targets for prevention and treatment in schizophrenia.

Cerebrospinal fluid biomarker candidates of schizophrenia: where do we stand?

Here, we review the cerebrospinal fluid (CSF) candidate markers with regard to their clinical relevance as potential surrogates for disease activity, prognosis assessment, and predictors of treatment response. We searched different online databases such as MEDLINE and EMBASE for studies on schizophrenia and CSF. Initial studies on cerebrospinal fluid in patients with schizophrenia revealed increased brain-blood barrier permeability with elevated total protein content, increased CSF-to-serum ratio for albumin, and intrathecal production of immunoglobulins in subgroups of patients. Analyses of metabolites in CSF suggest alterations within glutamatergic neurotransmission as well as monoamine and cannabinoid metabolism. Decreased levels of brain-derived neurotrophic factor and nerve growth factor in CSF of first-episode patients with schizophrenia reported in recent studies point to a dysregulation of neuroprotective and neurodevelopmental processes. Still, these findings must be considered as non-specific. A more profound characterization of the particular psychopathological profiles, the investigation of patients in the prodromal phase or within the first episode of schizophrenia promoting longitudinal investigations, implementation of different approaches of proteomics, and rigorous adherence to standard procedures based on international CSF guidelines are necessary to improve the quality of CSF studies in schizophrenia, paving the way for identification of syndrome-specific biomarker candidates.

Neuroimaging and treatment evidence for clinical staging in psychotic disorders: from the at-risk mental state to chronic schizophrenia

A new approach to understanding severe mental disorders such as schizophrenia is to adopt a clinical staging model. Such a model defines the extent of the illness such that earlier and milder phenomena are distinguished from later, more impairing features. Specifically, a clinical staging model makes three key predictions. First, pathologic measures should be more abnormal in more severe stages. Second, patients who progress between the stages should show change in these same pathologic measures. Finally, treatment should be more effective in the earlier stages, as well as more benign. In this article, we review the evidence for these three predictions from studies of psychotic disorders, with a focus on neuroimaging data. For all three, the balance of evidence supports the predictions of the staging model. However, there are a number of alternative explanations for these findings, including the effects of medication and symptom heterogeneity.

Antipsychotic medication for early episode schizophrenia

BACKGROUND

Long-term treatment with antipsychotic medications in early episode schizophrenia spectrum disorders is common, but both short and long-term effects on the illness are unclear. There have been numerous suggestions that people with early episodes of schizophrenia appear to respond differently than those with multiple prior episodes. The number of episodes may moderate response to drug treatment.

OBJECTIVES

To assess the effects of antipsychotic medication treatment on people with early episode schizophrenia spectrum disorders.

SEARCH STRATEGY

We searched the Cochrane Schizophrenia Group register (July 2007) as well as references of included studies. We contacted authors of studies for further data.

SELECTION CRITERIA

Studies with a majority of first and second episode schizophrenia spectrum disorders comparing initial antipsychotic medication treatment with placebo, milieu, or psychosocial treatment.

DATA COLLECTION AND ANALYSIS

Working independently, we critically appraised records from 681studies, of which five studies met inclusion criteria. John Rathbone from the Schizophrenia Group supported us with the data extraction. We calculated risk ratios (RR) and their 95% confidence intervals (CI) where possible. For continuous data, we calculated mean difference (MD). We calculated numbers needed to treat/harm (NNT/NNH) where appropriate.

MAIN RESULTS

Five studies with a combined N = 998 met inclusion criteria. Four studies (N = 724) provided leaving the study early data and results suggested that individuals treated with a typical antipsychotic medication are less likely to leave the study early than those treated with placebo (Chlorpromazine: 3 RCTs N = 353, RR 0.4 CI 0.3 to 0.5, NNT 3.2, Fluphenaxine: 1 RCT N = 240, RR 0.5 CI 0.3 to 0.8, NNT 5; Thioridazine: 1 RCT N = 236, RR 0.44 CI 0.3 to 0.7, NNT 4.3, Trifulperazine: 1 RCT N = 94, RR 0.96 CI 0.3 to 3.6). Two studies (Cole 1964; May 1976) contributed data to assessment of side effects and present a general pattern of more frequent side effects among individuals treated with typical antipsychotic medications compared to placebo. Rappaport 1978 suggested a higher rehospitalisation rate for those receiving chlorpromazine compared to placebo (N = 80, RR 2.29 CI 1.3 to 4.0, NNH 2.9). However, a higher attrition in the placebo group is likely to have introduced a survivor bias into this comparison, as this difference becomes non-significant in a sensitivity analysis on intent-to-treat participants (N = 127, RR 1.69 CI 0.9 to 3.0). One study (May 1976) contributes data to a comparison of trifluoperazine to psychotherapy on long-term health in favour of the trifluoperazine group (N = 92, MD 5.8 CI 1.6 to 0.0); however, data from this study are also likely to contain biases due to selection and attrition. One study (Mosher 1995) contributes data to a comparison of typical antipsychotic medication to psychosocial treatment on six-week outcome measures of global psychopathology (N = 89, MD 0.01 CI -0.6 to 0.6) and global improvement (N = 89, MD -0.03 CI -0.5 to 0.4), indicating no between-group differences. On the whole, there is very little useable data in the few studies meeting inclusion criteria.

AUTHORS' CONCLUSIONS

With only a few studies meeting inclusion criteria, and with limited useable data in these studies, it is not possible to arrive at definitive conclusions. The preliminary pattern of evidence suggests that people with early episode schizophrenia treated with typical antipsychotic medications are less likely to leave the study early, but more likely to experience medication-related side effects. Data are too sparse to assess the effects of antipsychotic medication on outcomes in early episode schizophrenia.

Reduction in perseverative errors with adjunctive ethyl-eicosapentaenoic acid in patients with schizophrenia: Preliminary study

INTRODUCTION

Patients with schizophrenia have significant cognitive deficits, generally resistant to conventional treatment. This preliminary study examined the effects of ethyl-eicosapentanoate (EPA) on an executive function in early course patients.

PATIENTS AND METHODS

Patients with schizophrenia were given, after an informed consent, 2 g of an EPA daily for 24 weeks, in an open-label study. The Wisconsin Card Sort Test (WCST) was administered at baseline, weeks 4, 12 and 24.

RESULTS

The 27 patients, with a mean duration of illness of 4.2 years, were all receiving atypical antipsychotics; treatment remained unchanged for the study. Perseverative errors - the key measure derived from WCST - were significantly reduced from the baseline mean of 28.2 to 18.4 errors at week 24. Positive symptoms also improved significantly. There were no correlations between EPA levels and any clinical or other neuropsychological measures.

CONCLUSION

These findings suggest that an EPA has procognitive effects for patients with schizophrenia, but controlled trials are required.

The case for including Attenuated Psychotic Symptoms Syndrome in DSM-5 as a psychosis risk syndrome

The American Psychiatric Association Task Force on DSM-5 has recently proposed consideration of Attenuated Psychotic Symptoms Syndrome as a new diagnosis, based on nearly 15 years of prospective research in centers across the globe. The condition is also known as "psychosis risk syndrome," "at-risk mental state," "ultra-high risk," and "putative prodrome." We review evidence favoring its inclusion as a new diagnosis in DSM-5 and report new preliminary findings on DSM-IV diagnoses in current clinical use for these patients and on results of diagnostic interviews in unselected volunteers. The main evidence supporting inclusion is: (1) the patients are currently ill, (2) the patients are at high risk for getting worse, (3) no DSM-IV diagnosis accurately captures their current illness or future risk, (4) the diagnosis has been made with reliability and validity in the research setting, and (5) placement in DSM-5 would help promote the needed treatment and prevention research to enable articulation of a standard of care to benefit these patients and their families. Potential harms can be minimized by patient, family, and provider education. It will be important to demonstrate through well-designed field trials whether the diagnostic criteria can be used with reliability in everyday clinical practice.

Dietary intake of fish, omega-3, omega-6 polyunsaturated fatty acids and vitamin D and the prevalence of psychotic-like symptoms in a cohort of 33,000 women from the general population

BACKGROUND

Low intake of fish, polyunsaturated fatty acids (PUFA) and vitamin D deficiency has been suggested to play a role in the development of schizophrenia. Our aim was to evaluate the association between the intake of different fish species, PUFA and vitamin D and the prevalence of psychotic-like symptoms in a population-based study among Swedish women.

METHODS

Dietary intake was estimated using a food frequency questionnaire among 33,623 women aged 30-49 years at enrollment (1991/92). Information on psychotic-like symptoms was derived from a follow-up questionnaire in the years 2002/03. Participants were classified into three predefined levels: low, middle and high frequency of symptoms. The association between diet and psychotic-like symptoms was summarized in terms of relative risks (RR) and corresponding 95% confidence intervals and was evaluated by energy-adjusted multinomial logistic regression.

RESULTS

18,411 women were classified as having a low level of psychotic-like symptoms, 14 395 as middle and 817 as having a high level. The risk of high level symptoms was 53% (95% CI, 30-69%) lower among women who ate fish 3-4 times per week compared to women who never ate fish. The risk was also lower for women with a high intake of omega-3 and omega-6 PUFA compared to women with a lower intake of these fatty acids. The effect was most pronounced for omega-6 PUFAs. The RR comparing the highest to the lowest quartile of omega-6 PUFAs intake was 0.78 (95% CI, 0.64-0.97). The associations were J-shaped with the strongest reduced risk for an intermediate intake of fish or PUFA. For fatty fish (herring/mackerel, salmon-type fish), the strongest inverse association was found for an intermediate intake (RR: 0.81, 95% CI, 0.66-0.98), whereas a high intake of fatty fish was associated with an increased risk of psychotic-like symptoms (RR: 1.90, 95% CI, 1.34-2.70). Women in the highest compared with the lowest quartile of vitamin D consumption experienced a 37% (95% CI, 22-50%) lower risk of psychotic-like symptoms.

CONCLUSION

Our findings raise a possibility that adult women with a high intake of fish, omega-3 or omega-6 PUFA and vitamin D have a lower rate of psychotic-like symptoms.

Deficit in prepulse inhibition in mice caused by dietary n-3 fatty acid deficiency

Docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA) may be biosynthesized from a precursor alpha-linolenic acid (LNA) or obtained preformed in the diet. Dams were fed four diets with different levels of the various n-3 fatty acids during pregnancy and lactation, and their offspring were weaned to the same diets: "n-3 Deficient," containing (as % total fatty acids) 0.07% of LNA; "Low LNA" (0.4%); "High LNA" (4.8%); and a "DHA + EPA" diet, containing 0.4% of LNA, 2% DHA, and 2% EPA. Sensorimotor gating was measured by prepulse inhibition (PPI) of the acoustic startle response in C57Bl6 mice. The n-3 Deficient and Low LNA diets caused a substantial deficit in PPI compared to the DHA + EPA diet, whereas the High LNA diet induced a less pronounced, but significant reduction of PPI. These are the first data that demonstrate a deficit in sensorimotor gating in rodents caused by an inadequate amount of the n-3 fatty acids in the diet. Our results differentiate the effects of a High LNA diet from one with added EPA and DHA even though the difference in brain DHA content is only 12% between these dietary groups.

[The influence of diet on mental health]

The influence of nutritional factors on brain metabolism and the course of mental illness are increasingly being addressed in international research. It is a matter of discussion whether dietary habits, e.g., the amount of fish or vegetables, have an effect on the incidence of certain illnesses. Furthermore an optimized or supplemented diet could offer therapeutic possibilities; one example is the role of polyunsaturated fatty acids as an add-on therapy in affective disorders. The limitations of psychopharmacotherapy (drug interactions, side effects, noncompliance) underline the theoretical and practical relevance of nutrition in mental illness, the more so as mentally ill patients (especially when demented, anorectic, depressed, or schizophrenic) are at higher risk of malnutrition anyway. Even if the therapeutic evidence is still limited and the effects may be relatively weak, nutritional assessment and an optimized diet can be recommended for every patient.

Omega-3 fatty acids as treatments for mental illness: which disorder and which fatty acid?

BACKGROUND

A growing number of observational and epidemiological studies have suggested that mental illness, in particular mood disorders, is associated with reduced dietary intake and/or cellular abundance of omega-3 polyunsaturated fatty acids (PUFA). This has prompted researchers to test the efficacy of omega-3 PUFA in a range of different psychiatric disorders. We have critically reviewed the double blind placebo controlled clinical trials published prior to April 2007 to determine whether omega-3 PUFA are likely to be efficacious in these disorders.

RESULTS

Most trials involved a small number of participants but were largely well designed. Omega-3 PUFA were well tolerated by both children and adults with mild gastrointestinal effects being the only consistently reported adverse event. For schizophrenia and borderline personality disorder we found little evidence of a robust clinically relevant effect. In the case of attention deficit hyperactivity disorder and related disorders, most trials showed at most small benefits over placebo. A limited meta-analysis of these trials suggested that benefits of omega-3 PUFA supplementation may be greater in a classroom setting than at home. Some evidence indicates that omega-3 PUFA may reduce symptoms of anxiety although the data is preliminary and inconclusive. The most convincing evidence for beneficial effects of omega-3 PUFA is to be found in mood disorders. A meta-analysis of trials involving patients with major depressive disorder and bipolar disorder provided evidence that omega-3 PUFA supplementation reduces symptoms of depression. Furthermore, meta-regression analysis suggests that supplementation with eicosapentaenoic acid may be more beneficial in mood disorders than with docosahexaenoic acid, although several confounding factors prevented a definitive conclusion being made regarding which species of omega-3 PUFA is most beneficial. The mechanisms underlying the apparent efficacy of omega-3 PUFA in mood disorders compared to schizophrenia are discussed as is a rational for the possibly greater efficacy of EPA compared to DHA.

CONCLUSION

While it is not currently possible to recommend omega-3 PUFA as either a mono- or adjunctive-therapy in any mental illness, the available evidence is strong enough to justify continued study, especially with regard to attentional, anxiety and mood disorders.