Relationship Between Polyunsaturated Fatty Acids and Psychopathology in the NEURAPRO Clinical Trial

Maternal separation regulates sensitivity of stress-induced depression in mice by affecting hippocampal metabolism

Depression is a serious mental illness. Previous studies found that early life stress (ELS) plays a vital role in the onset and progression of depression. However, relevant studies have not yet been able to explain the specific effects of early stress on stress-induced depression sensitivity and individual behavior during growth. Therefore, we constructed a maternal separation (MS) model and administered chronic social frustration stress at different stages of their growth while conducting metabolomics analysis on the hippocampus of mice. Our results showed that the immobility time of mice in the forced swimming test was significantly reduced at the end of MS. Meanwhile, mice with MS experience significantly decreased total movement distance in the open field test and sucrose preference ratio in the sucrose preference test when subjected to chronic social defeat stress (CSDS) during adolescence. In adulthood, the results were the opposite. In addition, we found that level changes in metabolites such as Beta-alanine, l-aspartic acid, 2-aminoadipic acid, and Glycine are closely related to behavioral changes. These metabolites are mainly enriched in Pantothenate, CoA biosynthesis, and Beta Alanine metabolism pathways. Our experiment revealed that the effects of ELS vary across different age groups. It will increase an individual's sensitivity to depression when facing CSDS in adolescence, but it will reduce their sensitivity to depression when facing CSDS in adulthood. This may be achieved by regulating the hippocampus's Pantothenate and CoA biosynthesis and Beta Alanine metabolism pathways represented by Beta-alanine, l-Aspartic acid, 2-aminoadipic acid, and Glycine metabolites.

Nutraceuticals in Psychiatric Disorders: A Systematic Review

Correct nutrition and diet are directly correlated with mental health, functions of the immune system, and gut microbiota composition. Diets with a high content of some nutrients, such as fibers, phytochemicals, and short-chain fatty acids (omega-3 fatty acids), seem to have an anti-inflammatory and protective action on the nervous system. Among nutraceuticals, supplementation of probiotics and omega-3 fatty acids plays a role in improving symptoms of several mental disorders. In this review, we collect data on the efficacy of nutraceuticals in patients with schizophrenia, autism spectrum disorders, major depression, bipolar disorder, and personality disorders. This narrative review aims to provide an overview of recent evidence obtained on this topic, pointing out the direction for future research.

A randomised double-blind placebo-controlled trial of minocycline and/or omega-3 fatty acids added to treatment as usual for at risk Mental States: The NAYAB study

BACKGROUND

Inflammatory mechanisms are thought to contribute to the onset of psychosis in persons with an at-risk mental state (ARMS). We investigated whether the anti-inflammatory properties of minocycline and omega-3 polyunsaturated fatty acids (omega-3), alone or synergistically, would prevent transition to psychosis in ARMS in a randomised, double-blind, placebo-controlled trial in Pakistan.

METHODS

10,173 help-seeking individuals aged 16-35 years were screened using the Prodromal Questionaire-16. Individuals scoring 6 and over were interviewed using the Comprehensive Assessment of At-Risk Mental States (CAARMS) to confirm ARMS. Participants (n = 326) were randomised to minocycline, omega-3, combined minocycline and omega-3 or to double placebo for 6 months. The primary outcome was transition to psychosis at 12 months.

FINDINGS

Forty-five (13.8 %) participants transitioned to psychosis. The risk of transition was greater in those randomised to omega-3 alone or in combination with minocycline (17.3.%), compared to 10.4 % in those not exposed to omega-3; a risk-ratio (RR) of 1.67, 95 % CI [0.95, 2.92] p = 0.07. The RR for transitions on minocycline vs. no minocycline was 0.86, 95 % CI [0.50, 1.49] p > 0.10. In participants who did not become psychotic, CAARMS and depression symptom scores were reduced at six and twelve months (mean CAARMS difference = 1.43; 95 % CI [0.33, 1.76] p < 0.01 in those exposed to omega-3. Minocycline did not affect CAARMS or depression scores.

INTERPRETATION

In keeping with other studies, omega-3 appears to have beneficial effects on ARMS and mood symptom severity but it increased transition to psychosis, which may reflect metabolic or developmental consequences of chronic poor nutrition in the population. Transition to psychosis was too rare to reveal a preventative effect of minocycline but minocycline did not improve symptom severity. ARMS symptom severity and transition to psychosis appear to have distinct pathogeneses which are differentially modulated by omega-3 supplementation.

FUNDING

The study was funded by the Stanley Research Medical Institute.

Analysis of polyunsaturated fatty acids in antipsychotic-free individuals with at-risk mental state and patients with first-episode schizophrenia

Introduction

Abnormalities in membrane phospholipids are considered one of the pathophysiological backgrounds for schizophrenia. This study, explores the fatty acid composition of erythrocyte membranes and its association with clinical characteristics in two groups: individuals with an at-risk mental state (ARMS) and patients experiencing their first-episode of schizophrenia (FES).

Materials and methods

This study measured erythrocyte membrane fatty acids in 72 antipsychotic-free individuals with ARMS, 18 antipsychotic-free patients with FES, and 39 healthy volunteers. Clinical symptoms and cognitive and social functions were assessed using the Positive and Negative Syndrome Scale (PANSS), Brief Assessment of Cognition in Schizophrenia (BACS), Schizophrenia Cognition Rating Scale (SCoRS), and Social and Occupational Functioning Assessment Scale (SOFAS).

Results

Eicosapentaenoic and docosapentaenoic acid levels were lower in the ARMS and FES groups than in the healthy control group. In contrast, nervonic acid (NA) levels were markedly higher in the ARMS and FES groups than in the controls, while only the FES group showed higher levels of arachidonic acid. Oleic acid and NA levels were significantly associated with PANSS scores in both the FES and ARMS groups, particularly for the negative and general subscores. However, the patient groups had no significant associations between the fatty acid composition and the BACS, SCoRS, and SOFAS scores. Furthermore, the baseline fatty acid composition did not differ between the ARMS individuals who later developed psychosis (N = 6) and those who were followed for more than 2 years without developing psychosis onset (N = 30).

Discussion

The findings suggest that abnormal fatty acid compositions may be shared in the early stages of schizophrenia and the clinical high-risk state for psychosis and may serve as vulnerability markers of psychopathology.

Membrane Lipids in Ultra-High-Risk Patients: Potential Predictive Biomarkers of Conversion to Psychosis

Alterations in membrane lipids are reported in schizophrenia. However, no conclusion can be drawn regarding the extended and predictive value of these alterations in persons at ultra-high risk of psychosis (UHR). Recent studies suggested that sterols' impact on psychiatric disorders was underestimated. Here, we simultaneously explored sterols, fatty acids (FA), and phospholipids (PL) in UHR persons for the first time. We analysed erythrocyte membrane lipids in 61 UHR persons, including 29 who later converted to psychosis (UHR-C) and 32 who did not (UHC-NC). We used gas chromatography for FA and liquid chromatography tandem with mass spectrometry for sterols and phospholipids. Among UHR individuals, elevated baseline membrane linoleic acid level was associated with conversion to psychosis (26.1% vs. 60.5%, p = 0.02). Combining sterols, FA, and PL membrane composition improved the prediction of psychosis onset (AUC = 0.73). This is the first report showing that membrane sterol participates, with other membrane lipids, in modulating the risk of psychosis. It suggests that membrane lipids could be used as biomarkers for personalised medicine in UHR patients.

Complementary/Integrative Medicine Treatment and Prevention of Youth Psychosis

The rationale for CIM treatments in youth psychoses is to optimize treatment by targeting symptoms not resolved by antipsychotics, such as negative symptoms (major drivers of disability). Adjunctive omega-3 fatty acids (ω-3 FA) or N-acetyl cystine (NAC usage for > 24-week) can potentially reduce negative symptoms and improve function. ω-3 FA or exercise may prevent progression to psychosis in youth (in prodromal stage). Weekly 90-minute moderate to vigorous physical activity or aerobic exercise can reduce positive and negative symptoms. Awaiting better research, CIM agents are also recommended because they are devoid of any serious side-effects.

Effects of Fish-Oil Consumption on Psychological Function Outcomes in Psychosis: A Systematic Review and Dose-Response Meta-Analysis of Randomized Controlled Trials

Research on the effects of fish oil on clinical symptoms and psychosocial functioning in people with psychosis has been inconsistent. We conducted this systematic review and meta-analysis to summarize the available data on the effects of oral intake of fish oil on psychological functioning in patients with psychosis. Three online databases including PubMed, Scopus, and Web of Science were searched to identify relevant studies published by April 2021. The exposure was oral fish-oil supplementation. The Positive and Negative Syndrome Scale (PANSS), the Brief Psychiatric Rating Scale (BPRS), and the Global Assessment of Functioning (GAF) were our outcome measures. Seventeen randomized clinical trials involving 1390 patients were included. No change in PANSS was observed following oral fish-oil intake [weighted mean difference (WMD): -0.87; 95% CI: -16.99, 15.26; P = 0.92]. In a nonlinear dose-response analysis, a significant inverse association was observed between <10 wk of fish-oil supplementation and PANSS (WMD: -10; P-nonlinearity = 0.02). Although analysis of 4 studies showed a nonsignificant reduction in BPRS after fish-oil intake (WMD: -2.990; 95% CI: -6.42, 0.44; P = 0.08), a nonlinear dose-response analysis revealed significant inverse associations between dose (>2200 mg/d) and duration of fish-oil supplementation (<15 wk) with BPRS score (WMD: -8; P-nonlinearity = 0.04). Combined effect sizes from 6 randomized clinical trials showed significant increases in GAF after oral administration of fish oil (WMD: 6.66; 95% CI: 3.39, 9.93; P < 0.001). In conclusion, we did not find any significant changes in PANSS and BPRS scores following fish-oil supplementation. Nevertheless, oral fish-oil intake significantly contributed to improvement in GAF scores. This is the first meta-analysis to examine the effects of fish oil on the psychological functioning scores of PANSS, BPRS, and GAF simultaneously.

Omega-3 fatty acid in ultra-high-risk psychosis: A systematic review based on functional outcome

AIM

Among different types of poly unsaturated fatty acids, omega-3 fatty acids (FA) play a substantial role in brain development and functioning. This review was designed to evaluate and synthesize available evidence regarding omega-3 FAs and functional outcome in the ultra-high-risk (UHR) population.

METHODS

An electronic search in PubMed, EMBASE, PSYCINFO and COCHRANE search engines has been performed for all articles published until January 2019. The studies that have data regarding omega-3 FAs and functional outcome in UHR population were included.

RESULTS

Out of 397 nonduplicate citations, 19 articles met selection criteria. These articles were from four different primary studies, namely the Program of Rehabilitation and Therapy (PORT), the North American Prodromal Longitudinal Studies (NAPLS), Vienna High Risk study (VHR) and the NEURAPRO. The data from the NAPLS study found a positive correlation between functional improvement and frequency of dietary intake omega-3 FA. Moreover, among the erythrocyte omega-3 FA only eicosapentaenoic acid (EPA) showed a positive correlation with functional score. The VHR study found long-term improvement in functional outcome in omega-3 group compared to control, whereas such difference was noticed in the NEURAPRO. In the VHR study both omega-3 and omega-6 together predicted the functional improvement at 12 weeks.

CONCLUSIONS

The number of studies available remains insufficient and more studies with standardized outcome measures in a clinically comparable UHR population would be of more value to understand the clinical benefits of omega-3 FA in the UHR population.

Distress Related to Attenuated Psychotic Symptoms: Static and Dynamic Association With Transition to Psychosis, Nonremission, and Transdiagnostic Symptomatology in Clinical High-Risk Patients in an International Intervention Trial

This study examined whether distress in relation to attenuated psychotic symptoms (DAPS) is associated with clinical outcomes in an ultra-high risk (UHR) for psychosis sample. We also investigated whether DAPS is associated with cognitive style (attributional style and cognitive biases) and whether amount of psychosocial treatment provided is associated with reduction in DAPS. The study was a secondary analysis of the "Neurapro" clinical trial of omega-3 fatty acids. Three hundred and four UHR patients were recruited across 10 early intervention services. Data from baseline assessment, regular assessments over 12 months, and medium term follow-up (mean = 3.4 years) were used for analysis. Findings indicated: a positive association between DAPS assessed over time and transition to psychosis; a significant positive association between baseline and longitudinal DAPS and transdiagnostic clinical and functional outcomes; a significant positive association between baseline and longitudinal DAPS and nonremission of UHR status. There was no relationship between severity of DAPS and cognitive style. A greater amount of psychosocial treatment (cognitive-behavioral case management) was associated with an increase in DAPS scores. The study indicates that UHR patients who are more distressed by their attenuated psychotic symptoms are more likely to have a poorer clinical trajectory transdiagnostically. Assessment of DAPS may therefore function as a useful marker of risk for a range of poor outcomes. The findings underline the value of repeated assessment of variables and incorporation of dynamic change into predictive modeling. More research is required into mechanisms driving distress associated with symptoms and the possible bidirectional relationship between symptom severity and associated distress.

The association of plasma inflammatory markers with omega-3 fatty acids and their mediating role in psychotic symptoms and functioning: An analysis of the NEURAPRO clinical trial

There is increasing evidence that dysregulation of polyunsaturated fatty acids (FAs) mediated membrane function plays a role in the pathophysiology of schizophrenia. Even though preclinical findings have supported the anti-inflammatory properties of omega-3 FAs on brain health, their biological roles as anti-inflammatory agents and their therapeutic role on clinical symptoms of psychosis risk are not well understood. In the current study, we investigated the relationship of erythrocyte omega-3 FAs with plasma immune markers in a clinical high risk for psychosis (CHR) sample. In addition, a mediation analysis was performed to examine whether previously reported associations between omega-3 FAs and clinical outcomes were mediated via plasma immune markers. Clinical outcomes for CHR participants in the NEURAPRO clinical trial were measured using the Brief Psychiatric Rating Scale (BPRS), Schedule for the Scale of Assessment of Negative Symptoms (SANS) and Social and Occupational Functioning Assessment Scale (SOFAS) scales. The erythrocyte omega-3 index [eicosapentaenoic acid (EPA) + docosahexaenoic acid (DHA)] and plasma concentrations of inflammatory markers were quantified at baseline (n = 268) and 6 month follow-up (n = 146) by gas chromatography and multiplex immunoassay, respectively. In linear regression models, the baseline plasma concentrations of Interleukin (IL)-15, Intercellular adhesion molecule (ICAM)-1 and Vascular cell adhesion molecule (VCAM)-1 were negatively associated with baseline omega-3 index. In addition, 6-month change in IL-12p40 and TNF-α showed a negative association with change in omega-3 index. In longitudinal analyses, the baseline and 6 month change in omega-3 index was negatively associated with VCAM-1 and TNF-α respectively at follow-up. Mediation analyses provided little evidence for mediating effects of plasma immune markers on the relationship between omega-3 FAs and clinical outcomes (psychotic symptoms and functioning) in CHR participants. Our results indicate a predominantly anti-inflammatory relationship of omega-3 FAs on plasma inflammatory status in CHR individuals, but this did not appear to convey clinical benefits at 6 month and 12 month follow-up. Both immune and non-immune biological effects of omega-3 FAs would be resourceful in understanding the clinical benefits of omega-3 FAs in CHR papulation.

Nutrition, Exercise, and Stress Management for Treatment and Prevention of Psychiatric Disorders. A Narrative Review Psychoneuroendocrineimmunology-Based

Psychoneuroendocrineimmunology (PNEI) brings together knowledge acquired since the 1930s from endocrinology, immunology, neuroscience, and psychology. With PNEI, a model of research and interpretation of health and disease is emerging, which sees the human body as a structured and interconnected unit, where the psychological and biological systems are mutually coordinated. In the PNEI view, many factors could influence mental health, with the endocrine system involved in mediating the effects of environmental stress on mental health and inflammation in the onset and course of psychiatric disorders as a result of individual and collective conditions and behaviors. Among these, nutrition is one way by which the environment impacts physiology: indeed, many pieces of research showed that several elements (e.g., probiotics, fish oil, zinc) have a positive effect on mental disorders thus being potentially augmentation agents in treatment. Still, physical activity can moderate depressive symptoms, while prolonged stress increases the risk of psychopathology. Taken together, the PNEI-based approach may inform prevention and treatment strategies, also in the field of mental health care.

Mental Health in Childhood and Adolescence: The Role of Polyunsaturated Fatty Acids

There is increasing awareness of the importance of polyunsaturated fatty acids (PUFAs) for optimal brain development and function. In recent decades, researchers have confirmed the central role of PUFAs in a variety of patho-physiological processes. These agents modulate the mechanisms of brain cell signalling including the dopaminergic and serotonergic pathways. Therefore, nutritional insufficiencies of PUFAs may have adverse effects on brain development and developmental outcomes. The role of n-3 PUFAs has been studied in several psychiatric disorders in adulthood: 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. In contrast to the great number of studies conducted in adults, there are only limited data on the effects of n-3 PUFA supplementation in children and adolescents who suffer from mental disorders or show a high risk of developing psychiatric disorders. The aim of this review is to provide a complete and updated account of the available evidence of the impact of polyunsaturated fatty acids on developmental psychopathology in children and adolescents and the effect of fatty acid supplementation during developmental milestones, particularly in high-risk populations of children with minimal but detectable signs or symptoms of mental disorders.

Shared Biological Pathways between Antipsychotics and Omega-3 Fatty Acids: A Key Feature for Schizophrenia Preventive Treatment?

Schizophrenia typically emerges during adolescence, with progression from an ultra-high risk state (UHR) to the first episode of psychosis (FEP) followed by a chronic phase. The detailed pathophysiology of schizophrenia and the factors leading to progression across these stages remain relatively unknown. The current treatment relies on antipsychotics, which are effective for FEP and chronic schizophrenia but ineffective for UHR patients. Antipsychotics modulate dopaminergic and glutamatergic neurotransmission, inflammation, oxidative stress, and membrane lipids pathways. Many of these biological pathways intercommunicate and play a role in schizophrenia pathophysiology. In this context, research of preventive treatment in early stages has explored the antipsychotic effects of omega-3 supplementation in UHR and FEP patients. This review summarizes the action of omega-3 in various biological systems involved in schizophrenia. Similar to antipsychotics, omega-3 supplementation reduces inflammation and oxidative stress, improves myelination, modifies the properties of cell membranes, and influences dopamine and glutamate pathways. Omega-3 supplementation also modulates one-carbon metabolism, the endocannabinoid system, and appears to present neuroprotective properties. Omega-3 has little side effects compared to antipsychotics and may be safely prescribed for UHR patients and as an add-on for FEP patients. This could to lead to more efficacious individualised treatments, thus contributing to precision medicine in psychiatry.

Prediction of clinical outcomes beyond psychosis in the ultra-high risk for psychosis population

AIM

Several prediction models have been introduced to identify young people at greatest risk of transitioning to psychosis. To date, none has examined the possibility of developing a clinical prediction model of outcomes other than transition. The aims of this study were to examine the association between baseline clinical predictors and outcomes including, but not limited to, transition to psychosis in young people at risk for psychosis, and to develop a prediction model for these outcomes.

METHODS

Several evidence-based variables previously associated with transition to psychosis and some important clinical comorbidities experienced by ultra-high risk (UHR) individuals were identified in 202 UHR individuals. Secondary analysis of the Neurapro clinical trial were conducted to investigate the associations between these variables and favourable (remission and recovery) or unfavourable (transition to psychosis, no remission, any recurrence and relapse) clinical outcomes. Logistic regression, best subset selection, Akaike Information Criterion and receiver operating characteristic curves were used to seek the best prediction model for clinical outcomes from all combinations of possible predictors.

RESULTS

When considered individually, only higher general psychopathology levels (P = .023) was associated with the unfavourable outcomes. Prediction models suggest that general psychopathology and functioning are predictive of unfavourable outcomes.

CONCLUSION

The predictive performance of the resulting models was modest and further research is needed. Nonetheless, when designing early intervention centres aiming to support individuals in the early phases of a mental disorder, the proper assessment of general psychopathology and functioning should be considered in order to inform interventions and length of care provided.

Plasma polyunsaturated fatty acids and mental disorders in adolescence and early adulthood: cross-sectional and longitudinal associations in a general population cohort

Polyunsaturated fatty acids (PUFAs) may be pertinent to the development of mental disorders, for example via modulation of inflammation and synaptogenesis. We wished to examine cross-sectional and longitudinal associations between PUFAs and mental disorders in a large cohort of young people. Participants in the Avon Longitudinal Study of Parents and Children were interviewed and provided blood samples at two sampling periods when approximately 17 and 24 years old. Plasma PUFA measures (total omega-6 [n-6], total omega-3 [n-3], n-6:n-3 ratio and docosahexaenoic acid [DHA] percentage of total fatty acids) were assessed using nuclear magnetic resonance spectroscopy. Cross-sectional and longitudinal associations between standardised PUFA measures and three mental disorders (psychotic disorder, moderate/severe depressive disorder and generalised anxiety disorder [GAD]) were measured by logistic regression, adjusting for age, sex, body mass index and cigarette smoking. There was little evidence of cross-sectional associations between PUFA measures and mental disorders at age 17. At age 24, the n-6:n-3 ratio was positively associated with psychotic disorder, depressive disorder and GAD, while DHA was inversely associated with psychotic disorder. In longitudinal analyses, there was evidence of an inverse association between DHA at age 17 and incident psychotic disorder at age 24 (adjusted odds ratio 0.44, 95% confidence interval 0.22-0.87) with little such evidence for depressive disorder or GAD. There was little evidence for associations between change in PUFA measures from 17 to 24 years and incident mental disorders at 24 years. These findings provide support for associations between PUFAs and mental disorders in early adulthood, and in particular, for DHA in adolescence in relation to prevention of psychosis.

Perinatal Dietary Polyunsaturated Fatty Acids in Brain Development, Role in Neurodevelopmental Disorders

n-3 and n-6 polyunsaturated fatty acids (PUFAs) are essential fatty acids that are provided by dietary intake. Growing evidence suggests that n-3 and n-6 PUFAs are paramount for brain functions. They constitute crucial elements of cellular membranes, especially in the brain. They are the precursors of several metabolites with different effects on inflammation and neuron outgrowth. Overall, long-chain PUFAs accumulate in the offspring brain during the embryonic and post-natal periods. In this review, we discuss how they accumulate in the developing brain, considering the maternal dietary supply, the polymorphisms of genes involved in their metabolism, and the differences linked to gender. We also report the mechanisms linking their bioavailability in the developing brain, their transfer from the mother to the embryo through the placenta, and their role in brain development. In addition, data on the potential role of altered bioavailability of long-chain n-3 PUFAs in the etiologies of neurodevelopmental diseases, such as autism, attention deficit and hyperactivity disorder, and schizophrenia, are reviewed.

Longitudinal investigation of the relationship between omega-3 polyunsaturated fatty acids and neuropsychological functioning in recent-onset psychosis: A randomized clinical trial

Alterations in polyunsaturated fatty acids (PUFAs), including omega-3 and omega-6, have been implicated in the pathophysiology of psychotic disorders, but little is known about their associations with neuropsychological functioning. The present study includes 46 recent-onset psychosis patients who participated in a larger (n = 50) double blind, placebo-controlled randomized clinical trial comparing 16 weeks of treatment with either risperidone + fish oil (FO) (EPA 740 mg and DHA 400 mg daily) or risperidone + placebo and completed neuropsychological assessments at the baseline timepoint. We investigated the relationship between baseline omega-3 (i.e., eicosapentaenoic acid, EPA; docosapentaenoic acid, DPA and docosahexaenoic acid, DHA) and omega-6 (i.e., arachidonic acid, AA) PUFA with baseline MATRICS Consensus Cognitive Battery (MCCB) and Brief Psychiatric Rating Scale (BPRS) scores. Twenty-five patients had neuropsychological data available at 16 weeks following participation in the clinical trial, which included 12 patients assigned to risperidone + FO and 13 patients assigned to risperidone + placebo. At baseline both higher DHA and EPA correlated significantly with better social cognition after controlling for functioning on other neuropsychological domains, total BPRS score, AA level and substance use. Also, at baseline higher AA correlated significantly with hostility/uncooperativeness after controlling for DHA + EPA + DPA, overall neuropsychological functioning and substance use. Patients treated with risperidone + FO demonstrated a significant longitudinal increase in social cognition that was significantly higher at 16 weeks compared to patients treated with risperidone + placebo. DHA also correlated significantly with social cognition at the 16-week timepoint. This study provides novel evidence for a differential role of omega-3 vs. omega-6 PUFA in neuropsychological deficits and symptoms in recent-onset psychosis and its treatment.

Peroxisome proliferator-activated receptor α as a novel therapeutic target for schizophrenia

BACKGROUND

The pathophysiology of schizophrenia, a major psychiatric disorder, remains elusive. In this study, the role of peroxisome proliferator-activated receptor (PPAR)/retinoid X receptor (RXR) families, belonging to the ligand-activated nuclear receptor superfamily, in schizophrenia, was analyzed.

METHODS

The PPAR/RXR family genes were screened by exploiting molecular inversion probe (MIP)-based targeted next-generation sequencing (NGS) using the samples of 1,200 Japanese patients with schizophrenia. The results were compared with the whole-genome sequencing databases of the Japanese cohort (ToMMo) and the gnomAD. To reveal the relationship between PPAR/RXR dysfunction and schizophrenia, Ppara KO mice and fenofibrate (a clinically used PPARα agonist)-administered mice were assessed by performing behavioral, histological, and RNA-seq analyses.

FINDINGS

Our findings indicate that c.209-2delA, His117Gln, Arg141Cys, and Arg226Trp of the PPARA gene are risk variants for schizophrenia. The c.209-2delA variant generated a premature termination codon. The three missense variants significantly decreased the activity of PPARα as a transcription factor in vitro. The Ppara KO mice exhibited schizophrenia-relevant phenotypes, including behavioral deficits and impaired synaptogenesis in the cerebral cortex. Oral administration of fenofibrate alleviated spine pathology induced by phencyclidine, an N-methyl-d-aspartate (NMDA) receptor antagonist. Furthermore, pre-treatment with fenofibrate suppressed the sensitivity of mice to another NMDA receptor antagonist, MK-801. RNA-seq analysis revealed that PPARα regulates the expression of synaptogenesis signaling pathway-related genes.

INTERPRETATION

The findings of this study indicate that the mechanisms underlying schizophrenia pathogenesis involve PPARα-regulated transcriptional machinery and modulation of synapse physiology. Hence, PPARα can serve as a novel therapeutic target for schizophrenia.

Cerebellar mitochondrial dysfunction and concomitant multi-system fatty acid oxidation defects are sufficient to discriminate PTSD-like and resilient male mice

The impact of trauma on mental health is complex with poorly understood underlying mechanisms. Mitochondrial dysfunction is increasingly implicated in psychopathologies and mood disorders, including post-traumatic stress disorder (PTSD). We hypothesized that defects in mitochondrial energy metabolism in the cerebellum, an emerging region of interest in the pathobiology of mood disorders, would be associated with PTSD-like symptomatology, and that PTSD-like symptomatology would correlate with the activities of the mitochondrial electron transport chain (mtETC) and fatty acid oxidation (FAO) pathways. We assayed mitochondrial energy metabolism and fatty acid profiling using targeted metabolomics in mice exposed to a recently developed paradigm for PTSD-induction. 48 wild type male FVB.129P2 mice were exposed to a trauma, and PTSD-like and resilient animals were identified using behavioral profiling. Mice displaying PTSD-like symptomatology displayed reduced mtETC complex activities in the cerebellum, and cerebellar mtETC complex activity negatively correlated with PTSD-like symptomatology. PTSD-like animals also displayed fatty acid profiles consistent with FAO dysfunction in both cerebellum and plasma. Machine learning analysis of all biochemical measures in this cohort of animals also identified plasma acetylcarnitine, along with reduced activity of cerebellar complex I and IV as well as succinate:cytochrome c oxidoreductase as state predictive discriminators of PTSD-symptomatology. Our data also suggest that trauma-induced impaired mtETC function in the cerebellum and concomitant impaired multi-system fatty acid oxidation are candidate drivers of PTSD-like behavior in mice. These bioenergetic and metabolic changes may offer an informative window into the underlying biology and highlight novel potential targets for diagnostics and therapeutic interventions in PTSD.

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.

Basic symptoms in young people at ultra-high risk of psychosis: Association with clinical characteristics and outcomes

There has been limited research into the predictive value of basic symptoms and their relationship with other psychopathology in patients identified using the 'ultra high risk' (UHR) for psychosis approach. The current study investigated whether basic symptoms, specifically cognitive disturbances (COGDIS), were associated with a greater risk of transition to psychotic disorder and persistent attenuated psychotic symptoms (APS) at medium term follow-up (mean = 3.4 years) in UHR patients, as well as with general psychopathology at baseline. The sample included 304 UHR participants (mean age = 19.12 years) involved in an international multicenter trial of omega-3 fatty acids. UHR individuals who also met the COGDIS criteria (basic symptoms risk criteria) did not have a greater risk of transition than those who met the UHR criteria alone. However, meeting COGDIS risk criteria was associated with a greater likelihood of meeting the UHR attenuated psychotic symptoms risk group (i.e., having persistent attenuated psychotic symptoms) at 12-month follow-up (odds ratio = 1.85; 95% CI = 1.03, 3.32). Greater severity of cognitive basic symptoms was also independently associated with more severe general psychopathology at study entry. The findings do not support the notion that combined risk identification approaches (UHR and basic symptoms) aid in the identification of individuals at greatest risk of psychosis, although this interpretation is limited by the modest transition to psychosis rate (13%) and the time of follow up. However, the findings indicate that basic symptoms may be a clinically useful marker of more severe general psychopathology in UHR groups and risk for persistent attenuated psychotic symptoms.