theanine and Schizophrenia

Anxiety disorders are highly prevalent in modern societies, and are ranked the sixth most important contributor of non-fatal negative health outcomes.

Topics: Animals; Antihypertensive Agents; Anxiety; Blood Pressure; Depressive Disorder, Major; Glutamates; Humans; Psychotropic Drugs; Schizophrenia; Sleep Aids, Pharmaceutical; Stress, Psychological

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.

Topics: Acetylcysteine; Antipsychotic Agents; Ascorbic Acid; Databases, Factual; Diet, Gluten-Free; Dietary Supplements; Fatty Acids, Unsaturated; Folic Acid; Glutamates; Humans; Melatonin; Oxidative Stress; Randomized Controlled Trials as Topic; Schizophrenia; Thioctic Acid; Vitamin B Complex; Vitamin D; Vitamin E

Inadequate responses to current schizophrenia treatments have accelerated research into novel therapeutic approaches.. This study investigated the efficacy and tolerability of adjunctive L-theanine, an ingredient with neuroimmunomodulatory and neuroprotective properties, for chronic schizophrenia.. Eighty chronic schizophrenia inpatients were equally assigned to receive risperidone (6 mg/day) plus either L-theanine (400 mg/day) or matched placebo in this 8-week, randomized, parallel-group, double-blind, placebo-controlled trial. The participants were assessed using the Positive and Negative Syndrome Scale (PANSS) by recording the results of subscales at baseline and weeks 4 and 8 to measure treatment efficacy. Additionally, the participants were assessed for the Hamilton Depression Rating Scale (HDRS) and adverse events, including the Extrapyramidal Symptom Rating Scale (ESRS).. Sixty patients, 30 in each group, were included in the analyses. All baseline demographic and clinical characteristics were comparable between the groups (p-values > 0.05). The reduction rates from baseline to endpoint in negative, general psychopathology, and total scores of PANSS were greater in the L-theanine group (p-values = 0.03, 0.01, and 0.04, respectively). Regarding general psychopathology scores, the reduction in the L-theanine group was also greater until week 4 (p-value < 0.01). The time × treatment interaction effect was significant on negative (p-value = 0.03), general psychopathology (p-value < 0.01), and total (p-value = 0.04) scores of PANSS, indicating additional improvements in the L-theanine group. The HDRS and side effects were comparable between the groups (p-values > 0.05).. L-Theanine adjunct to risperidone safely and tolerably outperformed adjunctive placebo for schizophrenia, and promising evidence indicated its effects on primary negative symptoms, which need to be scrutinized in further studies.. The study protocol was registered and published prospectively in the Iranian Registry of Clinical Trials ( http://www.irct.ir ; registration number: IRCT20090117001556N133) on 2020-12-12.

Topics: Antipsychotic Agents; Double-Blind Method; Drug Therapy, Combination; Humans; Inpatients; Iran; Psychiatric Status Rating Scales; Risperidone; Schizophrenia; Treatment Outcome

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).. 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.. 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.. 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.

Topics: Adult; Antipsychotic Agents; Brain; Case-Control Studies; Female; Glutamates; Glutamic Acid; Glutamine; Humans; Magnetic Resonance Spectroscopy; Male; Middle Aged; Schizophrenia; Sleep; Treatment Outcome

L-theanine is a unique amino acid present almost exclusively in the tea plant. It possesses neuroprotective, mood-enhancing, and relaxation properties. This is a first study designed to evaluate the efficacy and tolerability of L-theanine augmentation of antipsychotic treatment of patients with chronic schizophrenia and schizoaffective disorder.. 60 patients with DSM-IV schizophrenia or schizoaffective disorder participated in an 8-week, double-blind, randomized, placebo-controlled study. 400 mg/d of L-theanine was added to ongoing antipsychotic treatment from February 2006 until October 2008. The outcome measures were the Positive and Negative Syndrome Scale (PANSS), the Hamilton Anxiety Rating Scale (HARS), the Cambridge Neuropsychological Test Automated Battery (CANTAB) for neurocognitive functioning, and additional measures of general functioning, side effects, and quality of life.. 40 patients completed the study protocol. Compared with placebo, L-theanine augmentation was associated with reduction of anxiety (P = .015; measured by the HARS scale) and positive (P = .009) and general psychopathology (P < .001) scores (measured by the PANSS 3-dimensional model). According to the 5-dimension model of psychopathology, L-theanine produced significant reductions on PANSS positive (P = .004) and activation factor (P = .006) scores compared to placebo. The effect sizes (Cohen d) for these differences ranged from modest to moderate (0.09-0.39). PANSS negative and CANTAB task scores, general functioning, side effect, and quality of life measures were not affected by L-theanine augmentation. L-theanine was found to be a safe and well-tolerated medication.. L-theanine augmentation of antipsychotic therapy can ameliorate positive, activation, and anxiety symptoms in schizophrenia and schizoaffective disorder patients. Further long-term studies of L-theanine are needed to substantiate the clinically significant benefits of L-theanine augmentation.

Topics: Adult; Antipsychotic Agents; Cognition Disorders; Double-Blind Method; Drug Therapy, Combination; Female; Glutamates; Humans; Male; Middle Aged; Neuroprotective Agents; Neuropsychological Tests; Placebos; Psychotic Disorders; Schizophrenia; Schizophrenic Psychology; Treatment Outcome