Pre-treatment amygdala activation and habituation predict symptom change in post-traumatic stress disorder.

Trauma-focused psychotherapy approaches are the first-line treatment option for post-traumatic stress disorder (PTSD); however, up to a third of patients remain symptomatic even after completion of the treatment. Predicting which patients will respond to a given treatment option would support personalized treatments and improve the efficiency of healthcare systems. Although previous neuroimaging studies have examined possible pre-treatment predictors of response to treatment, the findings have been somewhat inconsistent, and no other study has examined habituation to stimuli as a predictor. In this study, 16 treatment-seeking adults (MAge = 43.63, n = 10 women) with a primary diagnosis of PTSD passively viewed pictures of emotional facial expressions during functional magnetic resonance imaging (fMRI). After scanning, participants rated facial expressions on both valence and arousal. Participants then completed eight weekly sessions of prolonged exposure (PE) therapy. PTSD symptom severity was measured before and after treatment. Overall, participants showed symptomatic improvement with PE. Consistent with hypotheses, lesser activation in the amygdala and greater activation in the ventromedial prefrontal cortex during the presentation of fearful vs. happy facial expressions, as well as a greater decline in amygdala activation across blocks of fearful facial expressions at baseline, were associated with greater reduction of PTSD symptoms. Given that the repeated presentation of emotional material underlies PE, changes in brain responses with repeated stimulus presentations warrant further studies as potential predictors of response to exposure therapies.

Plasma Anthranilic Acid and Leptin Levels Predict HAM-D Scores in Depressed Women.

OBJECTIVES: Major depressive disorder (MDD) is associated with dysregulations of leptin and tryptophan-kynurenine (Trp-Kyn) (TKP) pathways. Leptin, a pro-inflammatory cytokine, activates Trp conversion into Kyn. However, leptin association with down-stream Kyn metabolites in MDD is unknown. METHODS: Fasting plasma samples from 29 acutely ill drug-naïve (n = 16) or currently non-medicated (⩾6 weeks; n = 13) MDD patients were analyzed for leptin, Trp, Kyn, its down-stream metabolites (anthranilic [AA], kynurenic [KYNA], xanthurenic [XA] acids and 3-hydroxykynurenine [3HK]), C-reactive protein (CRP), neopterin, body mass index (BMI), and insulin resistance (HOMA-IR). Depression severity was assessed by HAM-D-21. RESULTS: In female (n = 14) (but not in male) patients HAM-D-21 scores correlated with plasma levels of AA (but not other Kyn metabolites) (rho = -0.644, P = .009) and leptin (Spearman's rho = -0.775, P = .001). Inclusion of AA into regression analysis improved leptin prediction of HAM-D from 48.5% to 65.9%. Actual HAM-D scores highly correlated with that calculated by formula: HAM-D = 34.8518-(0.5660 × leptin [ng/ml] + 0.4159 × AA [nmol/l]) (Rho = 0.84, P = .00015). In male (n = 15) (but not in female) patients leptin correlated with BMI, waist circumference/hip ratio, CRP, and HOMA-IR. CONCLUSIONS: Present findings of gender specific AA/Leptin correlations with HAM-D are important considering that AA and leptin are transported from plasma into brain, and that AA formation is catalyzed by kynureninase-the only TKP gene associated with depression according to genome-wide analysis. High correlation between predicted and actual HAM-D warrants further evaluation of plasma AA and leptin as an objective laboratory test for the assessment of depression severity in female MDD patients.

Benserazide, an Inhibitor of Peripheral Kynurenine Metabolism, Attenuates Olanzapine-Induced Weight Gain, Insulin Resistance, and Dyslipidemia in C57Bl/6j Mice.

Schizophrenia (Sz) patients, especially treated with atypical antipsychotics, are at high risk of the development of metabolic syndrome that increases morbidity and mortality and impairs compliance with treatment. Mechanism of the high association of metabolic syndrome with the use of atypical antipsychotics is not clear. Literature and our data suggest that chronic inflammation- or stress-induced dysregulation of the peripheral down-stream kynurenine (Kyn) metabolism, shared by both Sz and metabolic syndrome, contributes to the development of metabolic syndrome in Sz patients treated with atypical antipsychotics. Correction of dysregulation of the peripheral down-stream metabolism of Kyn would prevent/treat metabolic syndrome. This is a pre-clinical trial of the effect of benserazide (BRZ), an inhibitor of the key enzymes of Kyn metabolism, on olanzapine-induced mouse model of metabolic syndrome. Olanzapine is one of the most effective atypical antipsychotics but has high potential to induce metabolic syndrome. Olanzapine (4 mg/kg, p.o) and/or BRZ (100 mg/day, p.o.) were administered to 6-week-old C57Bl/6 female mice, 5 days/week, for 10 weeks. The study was approved by the Tufts Medical Center Institutional Animal Care and Use Committee. BRZ attenuated olanzapine-induced excessive weight gain, impairment of glucose tolerance, and elevation of plasma cholesterol and triglycerides. Present results suggest that peripheral down-stream Kyn metabolism is a new target for prevention/treatment of olanzapine-induced metabolic syndrome. BRZ has a high translational potential as medication already approved for human use.

Preventing suicide, promoting resilience: Is this achievable from a global perspective?

Suicide continues to be a major health concern globally despite many initiatives to identify risk factors and methods for suicide prevention. We have carried out a detailed narrative review of the literature from 2016 to 2019 using the headings of Personal resilience (P1), People (P2), Places (P3), Prevention (P4), Promoting collaboration (P5), and Promoting research (P6) in order to support an integrated approach to suicide prevention and the promotion of personal and population resilience. We have made 10 key recommendations on how this can be moved forward.

A case report of persistent risky dietary behaviors in a bipolar disorder patient.

BACKGROUND: Bipolar disorder is associated with complicated medical comorbidities. The risk-taking behavior of bipolar disorder patients may lead to many problems. CASE PRESENTATION: A 40-year-old male patient had gastrointestinal symptoms for 4 months. He was talkative, agitative, and grandiose but showed poor cognition. Multisystem injury required multidepartment, multidisciplinary consultation. Repeated fecal examination found multiple infections of Opisthorchis sinensis, Heterophyes, and Echinostomatidae. The diagnostic criteria for parasitic infections, bipolar disorder and organic mental disorder were met. After treatment with a mood stabilizer and helminthic, his mood became stable, but risky dietary behavior continued. CONCLUSIONS: The case describes persistent risky dietary behaviors in a bipolar patient even after affective symptoms were under control, which ultimately led to diverse parasitic infections and chronic encephalopathy. We call for clinical and scientific attention to possible dangerous behavior changes in bipolar patients even after their emotions are stabilized.

Peripheral kynurenine-3-monooxygenase deficiency as a potential risk factor for metabolic syndrome in schizophrenia patients.

Increased predisposition of schizophrenia patients (SP) to development of obesity and insulin resistance suggested common signaling pathway between metabolic syndrome (MetS) and schizophrenia. Deficiency of kynurenine-3-monooxygenase (KMO), enzyme catalyzing formation of 3-hydroxykynurenine (3-HK) from kynurenine (Kyn), a tryptophan (Trp) metabolite, might contribute to development of MetS as suggested by non-expression of KMO genes in human fat tissue and elevated serum concentrations of Kyn and its metabolites, kynurenic (KYNA) and anthranilic (ANA) acids, in diabetic patients and Zucker fatty rats (ZFR). Markers of KMO deficiency: decreased 3-HK and elevated Kyn, KYNA and ANA, were observed in brains and spinal fluids of SP, and in brains and serum of experimental animals with genetically- or pharmacologically-induced KMO deficiency. However, elevated concentrations of ANA and decreased 3-HK were reported in serum of SP without concurrent increase of Kyn and KYNA. Present study aimed to re-assess serum Kyn metabolites (HPLC-MS) in a sub-group of SP with elevated KYNA. We found increased Kyn concentrations (by 30%) and Kyn:Trp ratio (by 20%) in serum of SP with elevated KYNA concentrations (by 40%). Obtained results and our previous data suggest that peripheral KMO deficiency might be manifested by, at least, two different patterns: elevated ANA with decreased 3-HK; and elevated KYNA and KYN. The latter pattern was previously described in type 2 diabetes patients and might underline increased predisposition of SP to development of MetS. Assessment of peripheral KMO deficiency might identify SP predisposed to MetS. Attenuation of the consequences of peripheral KMO deficiency might be a new target for prevention/treatment of obesity and diabetes in SP.

A Consensus Statement on the Use of Ketamine in the Treatment of Mood Disorders.

IMPORTANCE: Several studies now provide evidence of ketamine hydrochloride's ability to produce rapid and robust antidepressant effects in patients with mood and anxiety disorders that were previously resistant to treatment. Despite the relatively small sample sizes, lack of longer-term data on efficacy, and limited data on safety provided by these studies, they have led to increased use of ketamine as an off-label treatment for mood and other psychiatric disorders. OBSERVATIONS: This review and consensus statement provides a general overview of the data on the use of ketamine for the treatment of mood disorders and highlights the limitations of the existing knowledge. While ketamine may be beneficial to some patients with mood disorders, it is important to consider the limitations of the available data and the potential risk associated with the drug when considering the treatment option. CONCLUSIONS AND RELEVANCE: The suggestions provided are intended to facilitate clinical decision making and encourage an evidence-based approach to using ketamine in the treatment of psychiatric disorders considering the limited information that is currently available. This article provides information on potentially important issues related to the off-label treatment approach that should be considered to help ensure patient safety.

Peripheral Tryptophan - Kynurenine Metabolism Associated with Metabolic Syndrome is Different in Parkinson's and Alzheimer's Diseases.

Insulin resistance (IR), obesity and other components of metabolic syndrome [MetS] are highly associated with Alzheimer's (AD) and Parkinson's (PD) diseases. Dysregulation of kynurenine (Kyn) pathway (KP) of tryptophan (Trp) metabolism was suggested as major contributor to pathogenesis of AD and PD and MetS. KP, the major source of NAD+ in humans, occurs in brain and peripheral organs. Considering that some, but not all, peripherally originated derivatives of Kyn penetrate blood brain barrier, dysregulation of central and peripheral KP might have different functional impact. Up-regulated Kyn formation from Trp was discovered in central nervous system of AD and PD while assessments of peripheral KP in these diseases yield controversial results. We were interested to compare peripheral kynurenines in AD and PD with emphasis on MetS-associated kynurenines, i.e., kynurenic (KYNA) and anthranilic (ANA) acids and 3-hydroxykynurenine (3-HK). Serum concentrations of KP metabolites were evaluated (HPLC-MS method). In PD patients Trp concentrations were lower, and Kyn: Trp ratio, Kyn, ANA and KYNA were higher than in controls. 3-HK concentrations of PD patients were below the sensitivity threshold of the method. In AD patients. ANA serum concentrations were approximately 3 fold lower, and KYNA concentrations were approximately 40% higher than in controls. Our data suggest different patterns of KP dysregulation in PD and AD: systemic chronic subclinical inflammation activating central and peripheral KP in PD, and central, rather than peripheral, activation of KP in AD triggered by Aß1-42. Dysregulation of peripheral KP in PD and AD patients might underline association between neurodegenerative diseases and MetS.

Bipolar disorder in the digital age: new tools for the same illness.

"Nothing is more difficult than to ascertain the length of time that a maniacal patient can exist without sleep."-Dr. Sutherland (Br J Psychiatry 7(37):1-19, 1861). Dr. Sutherland's patient was suffering from an acute manic episode, which today is called bipolar illness. 150 years later, we continue to struggle with the same challenges in ascertaining accurate symptoms from patients. In era of new digital tools, the quantified self-movement, and precision medicine, we can ask the question: Can we advance understanding and treatment for bipolar illness beyond asking the same questions as in 1861?

Attenuation of high sucrose diet-induced insulin resistance in ABC transporter deficient white mutant of Drosophila melanogaster.

Exposure to high sugar diet (HSD) is an experimental model of insulin resistance (IR) and type 2 diabetes (T2D) in mammals and insects. In Drosophila, HSD-induced IR delays emergence of pupae from larvae and eclosion of imago from pupae. Understanding of mechanisms of IR/T2D is essential for refining T2D prevention and treatment strategies. Dysregulation of tryptophan (Trp)-kynurenine (Kyn) pathway was suggested as one of the mechanisms of IR/T2D development. Rate-limiting enzyme of Trp-Kyn pathway in Drosophila is Trp 2,3-dioxygenase (TDO), an evolutionary conserved ortholog of human TDO. We previously reported attenuation of HSD-induced IR in vermilion mutants with inactive TDO. Conversion of Trp to Kyn is regulated not only by TDO activity but by intracellular Trp transport via ATP-binding cassette (ABC) transporter encoded by white gene in Drosophila. In order to evaluate the possible impact of deficient intracellular Trp transport on the inducement of IR by HSD, we compared the effect of HSD on pre-imago development in wild type flies, Canton-Special (C-S), and C-S flies containing white gene, white (C-S). Presence of white gene attenuated (by 50%) HSD-induced delay of pupae emergence from larvae and female and male imago eclosion from pupae. Present study together with our earlier report reveals that both decreased TDO activity (due to vermilion gene mutation) or deficient Trp transport into cell without affecting TDO levels (due to white gene mutation) attenuate HSD-induced development of IR in Drosophila model of T2D. Our data provide further support for hypothesis that dysregulation of Trp-Kyn pathway is one of the pathophysiological mechanisms and potential target for early diagnosis, prevention and treatment of IR/T2D.

Anthranilic Acid: A Potential Biomarker and Treatment Target for Schizophrenia.

Dysregulation of Trp-Kyn pathway is the most recent hypothesis of mechanisms of schizophrenia. In particular, over-production of kynurenic acid (KYNA), one of the three immediate downstream metabolites of kynurenine (Kyn) along tryptophan (Trp): Kyn pathway, has been considered as a new target for therapeutic intervention in schizophrenia. Up-regulation of KYNA formation was suggested to occur at the expense of down-regulated production of 3-hydroxyKyn (3-HK), the second immediate downstream metabolite of Kyn. We were interested to assess the third immediate downstream Kyn metabolite, anthranilic acid (AA). Serum AA concentrations were evaluated in schizophrenia patients and control subjects by HPLC-mass spectrometry method. We found 2-fold increase of AA and 3-fold decrease of 3-HK concentrations in serum of schizophrenia patients. Up regulated formation of AA might contribute to mechanisms of schizophrenia considering experimental evidences of AA augmentation of autoimmune processes in rat and mice; clinical findings of AA elevation in rheumatoid arthritis and type 1 diabetes, autoimmune diseases diametrical to schizophrenia; and involvement of autoimmunity in development of schizophrenia. Present data warrant further studies of AA as biological marker in, at least, a subgroup (associated with autoimmune mechanisms) of schizophrenia patients and as a new target for therapeutic intervention.

Elevated anthranilic acid plasma concentrations in type 1 but not type 2 diabetes mellitus.

Experimental data suggested involvement of tryptophan (Trp) - kynurenine (Kyn) pathway (TKP) in mechanisms of autoimmune, type 1 (T1D), and metabolic, type 2 (T2D), diabetes. However, clinical evaluations of TKP metabolites were limited to T2D. We assessed Trp, Kyn and TKP metabolites: anthranilic (AA), kynurenic (KYNA) and xanthurenic (XA) acids, in plasma samples of fifteen T1D, thirty T2D patients and twenty eight non-diabetic subjects by HPLC-mass spectrometry. Trp concentrations were higher in T1D than in T2D and controls while Kyn concentrations were not changed suggesting down-regulation of indoleamine-2,3-dioxygenase (IDO), a rate-limiting enzyme of TKP, in T1D. AA concentrations were 2.3-fold higher in T1D than in T2D and in controls. KYNA and XA concentrations were higher in T1D than in controls, and in previously reported T2D. AA elevation might be a specific feature of T1D. TKP shift towards AA formation in T1D may result from riboflavin deficiency, that increases AA in rats and baboons, and is highly associated with T1D but not T2D. AA augments autoimmune-induced apoptosis of pancreatic cells (PC) by increasing formation of antibodies to PC auto-antigen. Marked increase of AA was reported in rheumatoid arthritis, another autoimmune disorder. Trp, an essential amino acid for humans, is synthesized from AA by diabetogenic intestinal microbiome. AA down-regulates IDO by inhibition of Trp entry into cells. Resulting elevation of Trp attenuates Trp depletion-induced protection of PC against autoimmunity. Further studies of TKP might offer new tools for prevention and treatment of T1D and other autoimmune disorders.