Serum levels of brain-derived neurotrophic factor and cortisol to sulfate of dehydroepiandrosterone molar ratio associated with clinical response to L-theanine as augmentation of antipsychotic therapy in schizophrenia and schizoaffective disorder patients

Brain-Derived Neurotrophic Factor (BDNF) as a Predictor of Treatment Response in Schizophrenia and Bipolar Disorder: A Systematic Review

Brain-derived neurotrophic factor (BDNF) is a potential biomarker of response to treatment in psychiatric disorders. As it plays a role in the pathophysiological development of schizophrenia and bipolar disorder, it is of interest to study its role in predicting therapeutic responses in both conditions. We carried out a systematic review of the literature, looking for differences in baseline BDNF levels and the Val66Met BDNF polymorphism in these disorders between responders and non-responders, and found information showing that the Val/Val genotype and higher baseline BDNF levels may be present in patients that respond successfully to pharmacological and non-pharmacological treatments. However, there is still limited evidence to support the role of the Val66Met polymorphism and baseline BDNF levels as predictors of treatment response.

From periphery immunity to central domain through clinical interview as a new insight on schizophrenia

Identifying disease predictors through advanced statistical models enables the discovery of treatment targets for schizophrenia. In this study, a multifaceted clinical and laboratory analysis was conducted, incorporating magnetic resonance spectroscopy with immunology markers, psychiatric scores, and biochemical data, on a cohort of 45 patients diagnosed with schizophrenia and 51 healthy controls. The aim was to delineate predictive markers for diagnosing schizophrenia. A logistic regression model was used, as utilized to analyze the impact of multivariate variables on the prevalence of schizophrenia. Utilization of a stepwise algorithm yielded a final model, optimized using Akaike's information criterion and a logit link function, which incorporated eight predictors (White Blood Cells, Reactive Lymphocytes, Red Blood Cells, Glucose, Insulin, Beck Depression score, Brain Taurine, Creatine and Phosphocreatine concentration). No single factor can reliably differentiate between healthy patients and those with schizophrenia. Therefore, it is valuable to simultaneously consider the values of multiple factors and classify patients using a multivariate model.

The Effects of Polyphenol Supplementation on BDNF, Cytokines and Cognition in Trained Male Cyclists following Acute Ozone Exposure during High-Intensity Cycling

The neurotoxic effects of ozone exposure are related to neuroinflammation and increases in reactive oxygen species (ROS). This study aimed to assess inflammation, Brain-Derived Neurotrophic Factor (BDNF), and cognition in healthy male cyclists following polyphenol supplementation and exercise in an ozone-polluted environment. Ten male cyclists initially completed a maximal incremental test and maximal effort 4 km time trial in ambient air. Cyclists then completed two trials in an ozone-polluted environment (0.25 ppm) following 7 days of supplementation with either polyphenol (POLY) or placebo (PL). Experimental trials consisted of a three-stage submaximal test followed by a 4 km time trial. Blood samples were drawn pre- and post-exercise, and analyzed for BDNF, interleukin 6 (IL-6), interleukin 10 (IL-10) and tumor necrosis factor (TNF-α). The Stroop test and serial subtraction task were performed before ozone exposure and again after the 4 km TT. Serum BDNF increased post-exercise (p < 0.0001), and positive differences were observed post-exercise in the ozone POLY group relative to PL (p = 0.013). Plasma IL-6 increased post-exercise (p = 0.0015), and TNF-α increased post-ozone exposure (p = 0.0018). There were no differences in Stroop or serial subtraction tasks pre- or post-exercise. Exercise increases BDNF in ozone.

Brain foods - the role of diet in brain performance and health

The performance of the human brain is based on an interplay between the inherited genotype and external environmental factors, including diet. Food and nutrition, essential in maintenance of brain performance, also aid in prevention and treatment of mental disorders. Both the overall composition of the human diet and specific dietary components have been shown to have an impact on brain function in various experimental models and epidemiological studies. This narrative review provides an overview of the role of diet in 5 key areas of brain function related to mental health and performance, including: (1) brain development, (2) signaling networks and neurotransmitters in the brain, (3) cognition and memory, (4) the balance between protein formation and degradation, and (5) deteriorative effects due to chronic inflammatory processes. Finally, the role of diet in epigenetic regulation of brain physiology is discussed.

Selective Upregulation by Theanine of Slc38a1 Expression in Neural Stem Cell for Brain Wellness

Theanine is an amino acid abundant in green tea with an amide moiety analogous to glutamine (GLN) rather than glutamic acid (Glu) and GABA, which are both well-known as amino acid neurotransmitters in the brain. Theanine has no polyphenol and flavonoid structures required for an anti-oxidative property as seen with catechins and tannins, which are more enriched in green tea. We have shown marked inhibition by this exogenous amino acid theanine of the uptake of [³H]GLN, but not of [³H]Glu, in rat brain synaptosomes. Beside a ubiquitous role as an endogenous amino acid, GLN has been believed to be a main precursor for the neurotransmitter Glu sequestered in a neurotransmitter pool at glutamatergic neurons in the brain. The GLN transporter solute carrier 38a1 (Slc38a1) plays a crucial role in the incorporation of extracellular GLN for the intracellular conversion to Glu by glutaminase and subsequent sequestration at synaptic vesicles in neurons. However, Slc38a1 is also expressed by undifferentiated neural progenitor cells (NPCs) not featuring a neuronal phenotype. NPCs are derived from a primitive stem cell endowed to proliferate for self-renewal and to commit differentiation to several daughter cell lineages such as neurons, astrocytes, and oligodendrocytes. In vitro culture with theanine leads to the marked promotion of the generation of new neurons together with selective upregulation of Slc38a1 transcript expression in NPCs. In this review, we will refer to a possible novel neurogenic role of theanine for brain wellness through a molecular mechanism relevant to facilitated neurogenesis with a focus on Slc38a1 expressed by undifferentiated NPCs on the basis of our accumulating findings to date.

BDNF and Cortisol integrative system - Plasticity vs. degeneration: Implications of the Val66Met polymorphism

BDNF is the neurotrophin mediating pro-neuronal survival and plasticity. Cortisol (COR), in turn, is engaged in the coordination of several processes in the brain homeostasis. Stress-responsive, both factors show an integrative role through their receptor's dynamics in neurophysiology. Furthermore, the Val66Met BDNF polymorphism may play a role in this mechanism.

AIM

to investigate BDNF-COR interaction in the human neurophysiology context.

METHODS

We collected all papers containing BDNF and COR parameters or showing COR analyses in genotyped individuals in a PubMed search - full description available on PROSPERO - CRD42016050206.

DISCUSSION

BDNF and COR perform distinct roles in the physiology of the brain whose systems are integrated by glucocorticoid receptors dynamics. The BDNF polymorphism appears to have an influence on individual COR responsivity to stress. BDNF and COR play complementary roles in the nervous system where COR is a regulator of positive/negative effects. Exercise positively regulates both factors, regardless of BDNF polymorphism.

Psychotropic effects of L-theanine and its clinical properties: From the management of anxiety and stress to a potential use in schizophrenia

Anxiety disorders are highly prevalent in modern societies, and are ranked the sixth most important contributor of non-fatal negative health outcomes. _L-theanine is an amino acid naturally found in green tea (Camellia sinensis) and some other plant extracts, and recent clinical studies have proposed promising adjuvant effects of _L-theanine for the negative impact of anxiety and psychological stress on health. In this integrative narrative review, we aimed to appraise and further discuss the effects of _L-theanine administration on anxiety disorders and psychological stress. Published data suggests that _L-theanine administered at daily doses ranging from 200 to 400 mg for up to 8 weeks are safe and induce anxiolytic and anti-stress effects in acute and chronic conditions. _L-theanine at doses lower and higher than these may also show promising therapeutic potential; however, a more thorough investigation through randomized double-blind placebo-controlled crossover clinical trials are necessary to elucidate its effects for longer periods, providing further insights for meta-analyses and the development of recommendation guidelines. Additionally, animal studies investigating a higher dosage, its combination with other pharmacological compounds and associated metabolic comorbidities are recommended, as cases of hepatotoxicity associated with the consumption of green tea extract have been reported.

The role of glutamine in neurogenesis promoted by the green tea amino acid theanine in neural progenitor cells for brain health

The green tea amino acid theanine is abundant in green tea rather than black and oolong teas, which are all made of the identical tea plant "Chanoki" (Camellia sinensis). Theanine has a molecular structure close to glutamine (GLN) compared to glutamic acid (Glu), in terms of the absence of a free carboxylic acid moiety from the gamma carbon position. Theanine efficiently inhibits [³H]GLN uptake without affecting [³H]Glu uptake in rat brain synaptosomes. In contrast to GLN, however, theanine markedly stimulates the abilities to replicate and to commit to a neuronal lineage following prolonged exposure in cultured neural progenitor cells (NPCs) prepared from embryonic and adult rodent brains. Upregulation of transcript expression is found for one of the GLN transporter isoforms, Slc38a1, besides the promotion of both proliferation and neuronal commitment along with acceleration of the phosphorylation of mechanistic target of rapamycin (mTOR) and relevant downstream proteins, in murine NPCs cultured with theanine. Stable overexpression of Slc38a1 similarly facilitates both cellular replication and neuronal commitment in pluripotent embryonic carcinoma P19 cells. In P19 cells with stable overexpression of Slc38a1, marked phosphorylation is seen for mTOR and downstream proteins in a manner insensitive to further additional phosphorylation by theanine. Taken together, theanine would exhibit a novel pharmacological property to up-regulate Slc38a1 expression for activation of the intracellular mTOR signaling pathway required for neurogenesis after sustained exposure in undifferentiated NPCs in the brain. In this review, a novel neurogenic property of the green tea amino acid theanine is summarized for embryonic and adult neurogenesis with a focus on the endogenous amino acid GLN on the basis of our accumulating evidence to date.

[Neurobiological effects of theanine and its possible use in neurology and psychiatry]

Theanine is an analog of glutamate and the major aminoacid in green tea. It has received growing attention in recent years because of its beneficial effects on the central nervous system. Theanine was shown to increase levels of brain-derived neurotrophic factor and to stimulate neurogenesis. Anti-stress and calming effects of theanine are the most apparent and well-studied. A number of studies showed neuroprotective effects of theanine after an ischemic cerebral injury or the exposure to toxic chemicals. It also improved cognitive function including attention, memory and learning. Recent studies demonstrated a promising role of theanine in augmentation therapy for major depressive disorder and schizophrenia. Theoretical grounds for using theanine in treatment of bipolar disorder, anxiety disorder and some neurodegenerative disorders are discussed.

Current and potential pharmacological and psychosocial interventions for anxiety symptoms and disorders in patients with schizophrenia: structured review

OBJECTIVE

Between 30% and 62% of patients with schizophrenia present with co-morbid anxiety disorders that are associated with increased overall burden. Our aim was to summarize current and potential interventions for anxiety in schizophrenia.

DESIGN

Structured review, summarizing pharmacological and psychosocial interventions used to reduce anxiety in schizophrenia and psychosis.

RESULTS

Antipsychotics have been shown to reduce anxiety, increase anxiety, or have no effect. These may be augmented with another antipsychotic, anxiolytic, or antidepressant. Novel agents, such as L-theanine, pregabalin, and cycloserine, show promise in attenuating anxiety in schizophrenia. Psychosocial therapies have been developed to reduce the distress of schizophrenia. Cognitive behavioural therapy (CBT) has shown that benefit and refinements in the therapy have been successful, for example, for managing worry in schizophrenia. CBT usually involves more than 16 sessions, as short courses of CBT do not attenuate the presentation of anxiety in schizophrenia. To address time and cost, the development of manualized CBT to address anxiety in schizophrenia is being developed.

CONCLUSIONS

The presence of coexisting anxiety symptoms and co-morbid anxiety disorders should be ascertained when assessing patients with schizophrenia or other psychoses as a range of pharmacological and psychosocial treatments are available.

Behavioral Disturbances: An Innovative Approach to Monitor the Modulatory Effects of a Nutraceutical Diet

In dogs, diets are often used to modulate behavioral disturbances related to chronic anxiety and stress caused by intense and restless activity. However, the traditional ways to monitor behavioral changes in dogs are complicated and not efficient. In the current clinical evaluation, a new, simple monitoring system was used to assess the effectiveness of a specific diet in positively modulating the intense and restless activity of 24 dogs of different ages and breeds. This protocol describes how to easily and rapidly evaluate improvement in a set of symptoms related to generalized anxiety by using a specific sensor, a mobile phone app, a wireless router, and a computer. The results showed that dogs treated with specific diets showed significant improvement in the times spent active and at rest after 10 days (p < 0.01 and p < 0.05, respectively). These dogs also showed an overall significant improvement in clinical and behavioral symptoms. A specific sensor, along with its related hardware, was demonstrated to successfully monitor behavioral changes relating to movement in dogs.

Effects in dogs with behavioural disorders of a commercial nutraceutical diet on stress and neuroendocrine parameters

The well-being of dogs can be affected by changes in human lifestyle, eating habits and increased stressors that lead to behavioural disorders including fear, hyperactivity and anxiety, followed by negative affective moods and poor welfare. This randomised, controlled clinical evaluation involved 69 dogs, 38 males and 31 females, of different breeds, with behavioural disorders related to anxiety and chronic stress. They were fed a control diet or a nutraceutical diet (ND group) for 45 days. Neuroendocrine (serotonin, dopamine, β-endorphins, noradrenaline and cortisol) and stress (derivatives of reactive oxygen metabolites (dROMs) and biological antioxidant potential (BAP)) parameters related to behavioural disorders were evaluated at the beginning and end of the study period. Results showed a significant increase in serotonin, dopamine and β-endorphins plasma concentrations (*P<0.05, *P<0.05 and **P<0.01, respectively) and a significant decrease in noradrenaline and cortisol plasma concentrations in the ND group (*P<0.05). dROMs significantly decreased in the ND group (*P<0.05) while BAP was not affected. This study demonstrated for the first time that a specific diet significantly and positively affected neuroendocrine parameters and dROMs. These results open significant perspectives concerning the use of diet and nutraceuticals in the treatment of behavioural disorders.

The Efficacy of Non-Pharmacological Interventions on Brain-Derived Neurotrophic Factor in Schizophrenia: A Systematic Review and Meta-Analysis

Several studies have investigated the relationship between non-pharmacological interventions (NPIs) and peripheral brain-derived neurotrophic factor (BDNF) in schizophrenia patients. We conducted a systematic review and meta-analysis to review the efficacy of NPIs on peripheral serum and plasma BDNF in subjects with schizophrenia (including schizoaffective disorder). Meta-analyses were conducted to examine the effects of NPIs on blood BDNF levels by using the standardized mean differences (SMDs) between the intervention groups and controls. In total, six randomized controlled trials with 289 participants were included. Of them, five studies used exercise, physical training or diet products. One study used cognitive training. Overall, the BDNF levels in the NPI group increased significantly compared with the control groups (SMD = 0.95, 95% confidence interval (CI) = 0.07 to 1.83, p = 0.03). Subgroup analyses indicated beneficial effects of a non-exercise intervention on peripheral BDNF levels (SMD = 0.41, 95% CI = 0.08 to 0.74, p = 0.01). Meta-regression analyses showed that the completion rate influenced the variation in SMD (p = 0.01). Despite insufficient evidence to draw a conclusion, our results suggest that use of NPIs as adjunctive treatments, specifically non-exercise interventions, may affect positively serum or plasma BDNF in patients with schizophrenia.

Anxiety in Patients with Schizophrenia: Epidemiology and Management

Anxiety symptoms can occur in up to 65 % of patients with schizophrenia, and may reach the threshold for diagnosis of various comorbid anxiety disorders, including obsessive-compulsive disorder (OCD) and post-traumatic stress disorder (PTSD). We review the clinical presentation, diagnosis, neurobiology, and management of anxiety in patients with schizophrenia, with a particular focus on pharmacotherapy. The prevalence of any anxiety disorder (at syndrome level) in schizophrenia is estimated to be up to 38 %, with social anxiety disorder (SAD) being the most prevalent. Severity of positive symptoms may correlate with severity of anxiety symptoms, but anxiety can occur independently of psychotic symptoms. While anxiety may be associated with greater levels of insight, it is also associated with increased depression, suicidality, medical service utilization, and cognitive impairment. Patients with anxiety symptoms are more likely to have other internalizing symptoms as opposed to externalizing symptoms. Diagnosis of anxiety in schizophrenia may be challenging, with positive symptoms obscuring anxiety, lower levels of emotional expressivity and communication impeding diagnosis, and conflation with akathisia. Higher diagnostic yield may be achieved by assessment following the resolution of the acute phase of psychosis as well as by the use of screening questions and disorder-specific self-report instruments. In schizophrenia patients with anxiety, there is evidence of underactive fear circuitry during anxiety-provoking stimuli but increased autonomic responsivity and increased responsiveness to neutral stimuli. Recent findings implicate the serotonin transporter (SERT) genes, brain-derived neurotropic factor (BDNF) genes, and the serotonin 1a (5HT1a) receptor, but are preliminary and in need of replication. There are few randomized controlled trials (RCTs) of psychotherapy for anxiety symptoms or disorders in schizophrenia. For pharmacotherapy, data from a few randomized and open trials have shown that aripiprazole and risperidone may be efficacious for obsessive-compulsive and social anxiety symptoms, and quetiapine and olanzapine for generalized anxiety. Older agents such as trifluoperazine may also reduce comorbid anxiety symptoms. Alternative options include selective serotonin re-uptake inhibitor (SSRI) augmentation of antipsychotics, although evidence is based on a few randomized trials, small open trials, and case series, and caution is needed with regards to cytochrome P450 interactions and QTc interval prolongation. Buspirone and pregabalin augmentation may also be considered. Diagnosis and treatment of anxiety symptoms and disorders in schizophrenia is an important and often neglected aspect of the management of schizophrenia.

Antiglucocorticoid and related treatments for psychosis

BACKGROUND

Hypothalamic-pituitary-adrenal (HPA) axis dysregulation has been implicated in the development and relapse of psychotic disorders. Elevated cortisol secretion has been positively linked with symptom severity in people with psychosis. Antiglucocorticoid and related drugs that target the HPA axis may be useful for the treatment of individuals with psychosis.

OBJECTIVES

1. To determine the effects of antiglucocorticoid and related drugs for the treatment of psychosis, when used alone or in combination with antipsychotic medication.2. To determine whether the effects of these medications differs between those in a prodromal phase or first episode of psychosis, and those with more established illness.

SEARCH METHODS

We searched the Cochrane Schizophrenia Group's Trials Register (August 2009 and April 2014).

SELECTION CRITERIA

Randomised controlled trials (RCTs) comparing antiglucocorticoid and related drugs compared to placebo (either as a sole treatment or as an adjunct to atypical antipsychotics, typical antipsychotics, antidepressants or other combination treatment) for people with a primary diagnosis of a psychotic disorder, or for individuals at high risk of developing a psychotic disorder.

DATA COLLECTION AND ANALYSIS

Review authors independently selected trials, assessed methodological quality and extracted data. We used a fixed-effect meta-analysis. We calculated risk ratios (RRs) with 95% confidence intervals (CIs) for dichotomous outcomes, and mean differences (MDs) and standardised mean differences (SMDs) with 95% CIs for continuous measures. We assessed risk of bias for included studies and used GRADE (Grading of Recommendations Assessment, Development and Evaluation) to create a 'Summary of findings' table.

MAIN RESULTS

We included 11 studies that randomly assigned 509 people with schizophrenia, schizoaffective disorder or psychotic depression. No trials were conducted in patients at their first episode of psychotic illness and none included populations at high risk for developing psychosis. Our pre-stated outcomes of interest were mental state, global state, general functioning, adverse effects and quality of life.Two trials compared antiglucocorticoid drugs (mifepristone) versus placebo as sole treatment. Limited data from one trial showed no difference in the proportion responding to mifepristone when mental state was assessed immediately post intervention using the Brief Psychiatric Rating Scale (BPRS) (n = 5, 1 RCT, MD -5.20, 95% CI -17.91 to 7.51; very low-quality evidence); depressive symptoms (Hamilton Rating Scale for Depression (HAMD) total) were also similar between groups (n = 5, 1 RCT, MD 1.67, 95% CI -16.44 to 19.78; very low-quality evidence). However, a significant difference favoured treatment at short-term follow-up for global state (30% reduction in total BPRS, n = 221, 1 RCT, RR 0.58, 95% CI 0.38 to 0.89; low-grade quality evidence). This effect was also seen for short-term positive psychotic symptoms (50% reduction in BPRS positive symptom subscale, n = 221, 1 RCT, RR 0.60, 95% CI 0.43 to 0.84; low-grade quality evidence). Participants receiving mifepristone experienced a similar overall number of adverse effects as those receiving placebo (n = 226, 2 RCTs, RR 0.92, 95% CI 0.77 to 1.09; moderate-quality evidence). No data on general functioning or quality of life were available.One trial compared an antiglucocorticoid, dehydroepiandrosterone (DHEA), as an adjunct to atypical antipsychotic treatment to adjunctive placebo. Data for main outcomes of interest were of low quality, and analysis of useable data showed no significant effects of treatment on mental state or adverse effects. Data on global state, general functioning and quality of life were not available.Data from six trials comparing antiglucocorticoid drugs as an adjunct to combination treatment versus adjunctive placebo showed no significant differences between groups in mean endpoint scores for overall psychotic symptoms (n = 171, 6 RCTs, SMD 0.01, 95% CI - 0.29 to 0.32) or positive psychotic symptoms (n = 151, 5 RCTs, SMD -0.07, 95% CI - 0.40 to 0.25). Data from three trials showed no differences between groups in mean endpoint scores for negative symptoms (n = 94, 3 RCTs, MD 2.21, 95% CI -0.14 to 4.55). One study found improvements in global state that were similar between groups (n = 30, 1 RCT, RR 0.58, 95% CI 0.32 to 1.06; very low-quality evidence). In this comparison, pooled results showed that antiglucorticoids caused a greater overall number of adverse events (n = 199, 7 RCTs, RR 2.66, 95% CI 1.33 to 5.32; moderate quality evidence), but no quality of life data were available.

AUTHORS' CONCLUSIONS

Good evidence is insufficient to conclude whether antiglucocorticoid drugs provide effective treatment for psychosis. Some global state findings suggest a favourable effect for mifepristone, and a few overall adverse effect findings favour placebo. Additional large randomised controlled trials are needed to justify findings.

Incorporating Natural Products, Pharmaceutical Drugs, Self-Care and Digital/Mobile Health Technologies into Molecular-Behavioral Combination Therapies for Chronic Diseases

Merging pharmaceutical and digital (mobile health, mHealth) ingredients to create new therapies for chronic diseases offers unique opportunities for natural products such as omega-3 polyunsaturated fatty acids (n-3 PUFA), curcumin, resveratrol, theanine, or α-lipoic acid. These compounds, when combined with pharmaceutical drugs, show improved efficacy and safety in preclinical and clinical studies of epilepsy, neuropathic pain, osteoarthritis, depression, schizophrenia, diabetes and cancer. Their additional clinical benefits include reducing levels of TNFα and other inflammatory cytokines. We describe how pleiotropic natural products can be developed as bioactive incentives within the network pharmacology together with pharmaceutical drugs and self-care interventions. Since approximately 50% of chronically-ill patients do not take pharmaceutical drugs as prescribed, psychobehavioral incentives may appeal to patients at risk for medication non-adherence. For epilepsy, the incentive-based network therapy comprises anticonvulsant drugs, antiseizure natural products (n-3 PUFA, curcumin or/and resveratrol) coupled with disease-specific behavioral interventions delivered by mobile medical apps. The add-on combination of antiseizure natural products and mHealth supports patient empowerment and intrinsic motivation by having a choice in self-care behaviors. The incentivized therapies offer opportunities: (1) to improve clinical efficacy and safety of existing drugs, (2) to catalyze patient-centered, disease self-management and behavior-changing habits, also improving health-related quality-of-life after reaching remission, and (3) merging copyrighted mHealth software with natural products, thus establishing an intellectual property protection of medical treatments comprising the natural products existing in public domain and currently promoted as dietary supplements. Taken together, clinical research on synergies between existing drugs and pleiotropic natural products, and their integration with self-care, music and mHealth, expands precision/personalized medicine strategies for chronic diseases via pharmacological-behavioral combination therapies.

Effect of L-theanine on glutamatergic function in patients with schizophrenia

OBJECTIVES

Glutamatergic dysfunction in the brain has been implicated in the pathophysiology of schizophrenia. Previous studies suggested that L-theanine affects the glutamatergic neurotransmission and ameliorates symptoms in patients with schizophrenia. The aims of the present study were twofold: to examine the possible effects of L-theanine on symptoms in chronic schizophrenia patients and to evaluate the changes in chemical mediators, including glutamate + glutamine (Glx), in the brain by using 1H magnetic resonance spectroscopy (MRS).

METHOD

The subjects were 17 patients with schizophrenia and 22 age- and sex-matched healthy subjects. L-theanine (250 mg/day) was added to the patients' ongoing antipsychotic treatment for 8 weeks. The outcome measures were the Positive and Negative Syndrome Scale (PANSS), Pittsburgh Sleep Quality Index scores and MRS results.

RESULTS

There were significant improvements in the PANSS positive scale and sleep quality after the L-theanine treatment. As for MRS, we found no significant differences in Glx levels before and after the 8 week L-theanine treatment. However, significant correlations were observed between baseline density of Glx and change in Glx density by l-theanine.

CONCLUSIONS

Our results suggest that L-theanine is effective in ameliorating positive symptoms and sleep quality in schizophrenia. The MRS findings suggest that L-theanine stabilises the glutamatergic concentration in the brain, which is a possible mechanism underlying the therapeutic effect.

Nutritional interventions for the adjunctive treatment of schizophrenia: a brief review

Schizophrenia is a chronic condition that impacts significantly not only on the individual and family, but the disorder also has wider consequences for society in terms of significant costs to the economy. This highly prevalent condition affects approximately 1% of the worldwide population, yet there are few therapeutic options. The predominant treatment strategy for schizophrenia is anti-psychotic medication (with or without additional talking therapy) even though this approach lacks efficacy in managing the negative symptoms of the condition, is not effective in one-third of the patient group and the side effects of the medication can be severe and debilitating. In recent years, a number of pathophysiological processes have been identified in groups of people with schizophrenia including oxidative stress, one-carbon metabolism and immune-mediated responses. A number of studies have shown that these altered physiological mechanisms can be ameliorated by nutritional interventions in some individuals with schizophrenia. This review briefly describes the aforementioned processes and outlines research that has investigated the utility of nutritional approaches as an adjunct to anti-psychotic medication including antioxidant and vitamin B supplementation, neuroprotective and anti-inflammatory nutrients and exclusion diets. Whilst none of these interventions provides a ‘one-size-fits-all’ therapeutic solution, we suggest that a personalised approach warrants research attention as there is growing agreement that schizophrenia is a spectrum disorder that develops from the interplay between environmental and genetic factors.

Neurobiological effects of the green tea constituent theanine and its potential role in the treatment of psychiatric and neurodegenerative disorders

Theanine (n-ethylglutamic acid), a non-proteinaceous amino acid component of green and black teas, has received growing attention in recent years due to its reported effects on the central nervous system. It readily crosses the blood-brain barrier where it exerts a variety of neurophysiological and pharmacological effects. Its most well-documented effect has been its apparent anxiolytic and calming effect due to its up-regulation of inhibitory neurotransmitters and possible modulation of serotonin and dopamine in selected areas. It has also recently been shown to increase levels of brain-derived neurotrophic factor. An increasing number of studies demonstrate a neuroprotective effects following cerebral infarct and injury, although the exact molecular mechanisms remain to be fully elucidated. Theanine also elicits improvements in cognitive function including learning and memory, in human and animal studies, possibly via a decrease in NMDA-dependent CA1 long-term potentiation (LTP) and increase in NMDA-independent CA1-LTP. Furthermore, theanine administration elicits selective changes in alpha brain wave activity with concomitant increases in selective attention during the execution of mental tasks. Emerging studies also demonstrate a promising role for theanine in augmentation therapy for schizophrenia, while animal models of depression report positive improvements following theanine administration. A handful of studies are beginning to examine a putative role in attention deficit hyperactivity disorder, and theoretical extrapolations to a therapeutic role for theanine in other psychiatric disorders such as anxiety disorders, panic disorder, obsessive compulsive disorder (OCD), and bipolar disorder are discussed.

Cortisol levels and risk for psychosis: initial findings from the North American prodrome longitudinal study

BACKGROUND

Studies of biomarkers of hypothalamic-pituitary-adrenal activity indicate that psychotic disorders are associated with elevated cortisol. This study examined cortisol levels in healthy control subjects and individuals who met clinical high-risk (CHR) criteria for psychosis. It was hypothesized that cortisol levels would be 1) elevated in the CHR group relative to control subjects, 2) positively correlated with symptom severity, and 3) most elevated in CHR patients who transition to psychotic level severity.

METHODS

Baseline assessments were conducted at eight centers in the North American Prodrome Longitudinal Study. The present CHR sample included 256 individuals meeting the Scale for Prodromal Symptoms criteria and 141 control subjects, all of whom underwent baseline assessment and measurement of salivary cortisol.

RESULTS

Consistent with previous reports, there was an effect of age on cortisol, with increases through the adolescent/early adult years. Analysis of covariance showed a main effect of diagnostic group, with the CHR group showing higher cortisol. There were modest, positive correlations of cortisol with baseline symptom severity, and analysis of covariance revealed higher baseline cortisol in those who transitioned to psychotic level symptoms when compared with healthy control subjects and CHR subjects who remitted.

CONCLUSIONS

The present findings add to accumulating evidence of heightened cortisol secretion in CHR individuals. The findings also indicate nonspecific associations between cortisol levels and symptom severity, as well as symptom progression. The role of hypothalamic-pituitary-adrenal activity in prediction of conversion to psychosis and its relation with other biomarkers of risk should receive attention in future research.

Convergent functional genomics of schizophrenia: from comprehensive understanding to genetic risk prediction

We have used a translational convergent functional genomics (CFG) approach to identify and prioritize genes involved in schizophrenia, by gene-level integration of genome-wide association study data with other genetic and gene expression studies in humans and animal models. Using this polyevidence scoring and pathway analyses, we identify top genes (DISC1, TCF4, MBP, MOBP, NCAM1, NRCAM, NDUFV2, RAB18, as well as ADCYAP1, BDNF, CNR1, COMT, DRD2, DTNBP1, GAD1, GRIA1, GRIN2B, HTR2A, NRG1, RELN, SNAP-25, TNIK), brain development, myelination, cell adhesion, glutamate receptor signaling, G-protein-coupled receptor signaling and cAMP-mediated signaling as key to pathophysiology and as targets for therapeutic intervention. Overall, the data are consistent with a model of disrupted connectivity in schizophrenia, resulting from the effects of neurodevelopmental environmental stress on a background of genetic vulnerability. In addition, we show how the top candidate genes identified by CFG can be used to generate a genetic risk prediction score (GRPS) to aid schizophrenia diagnostics, with predictive ability in independent cohorts. The GRPS also differentiates classic age of onset schizophrenia from early onset and late-onset disease. We also show, in three independent cohorts, two European American and one African American, increasing overlap, reproducibility and consistency of findings from single-nucleotide polymorphisms to genes, then genes prioritized by CFG, and ultimately at the level of biological pathways and mechanisms. Finally, we compared our top candidate genes for schizophrenia from this analysis with top candidate genes for bipolar disorder and anxiety disorders from previous CFG analyses conducted by us, as well as findings from the fields of autism and Alzheimer. Overall, our work maps the genomic and biological landscape for schizophrenia, providing leads towards a better understanding of illness, diagnostics and therapeutics. It also reveals the significant genetic overlap with other major psychiatric disorder domains, suggesting the need for improved nosology.

l-theanine attenuates abstinence signs in morphine-dependent rhesus monkeys and elicits anxiolytic-like activity in mice

l-theanine, 2-amino-4-(ethylcarbamoyl) butyric acid, an amino acid found in green tea (Camellia sinensis), is sold in the United States as a dietary supplement to reduce stress and improve cognition and mood. The observations that l-theanine has been shown to inhibit caffeine's stimulatory effects and that caffeine produces precipitated withdrawal signs in opioid-addicted monkeys and some opioid withdrawal signs in some normal monkeys, suggest that l-theanine may suppress opioid withdrawal signs. Additionally, l-theanine produces anxiolytic effects in humans indicating that it has anti-anxiety properties. Thus, in these studies we determined whether l-theanine attenuates opioid-withdrawal signs in morphine-dependent rhesus monkeys, a model for spontaneous opioid withdrawal in human opioid addicts. We also evaluated whether l-theanine decreases anxiety-like behavior in mice, using the elevated plus maze and marble burying assays. l-theanine significantly attenuated designated opioid withdrawal signs, including fighting, rigid abdominal muscles, vocalizing on palpation of abdomen, pacing, retching, wet-dog shakes, and masturbation. It had a relatively quick onset of action that persisted for at least 2.5h. l-theanine also produced anxiolytic-like effects in the elevated plus maze and the marble burying assay in naïve mice at doses that did not significantly affect motor behavior. The results of these studies suggest that l-theanine may be useful in the pharmacotherapy of treating opioid withdrawal as well as anxiety-associated behaviors.