Oxidative imbalance in obsessive compulsive disorder patients: a total evaluation of oxidant-antioxidant status

The relationship between oxidative stress markers and 1H-Magnetic resonance spectroscopy findings in obsessive compulsive disorder

INTRODUCTION

The purpose of this study was to examine N-acetyl aspartate (NAA)/creatine (Cr) and glutamate, glutamine, and gamma-aminobutyric acid complex (Glx)/Cr levels in patients with obsessive compulsive disorder (OCD) and healthy controls' orbitofrontal cortex (OFC) and caudate nucleus (CN) by proton magnetic resonance spectroscopy (1H-MRS) method and to investigate their relationship with oxidative stress markers glutathione peroxidase (GPx) and superoxide dismutase (SOD).

METHODS

This study included patients with OCD (n = 25) and healthy controls (n = 25) ranging in age from 18 to 65. We used the ELISA method to evaluate serum SOD and GPx levels. Levels of NAA/Cr and Glx/Cr in the orbitofrontal cortex and caudate nucleus were measured using the 1H-MRS method.

RESULTS

Our study did not detect statistically significant differences in the orbitofrontal cortex Glx/Cr and NAA/Cr levels between the OCD patients and the control group. OCD patients exhibited a decrease in NAA/Cr levels, consistent with impaired neuronal integration, and an increase in Glx/Cr levels, consistent with hyperactivation, in the caudate nucleus compared to the control group. We observed a negative correlation between NAA/Cr levels in the caudate nucleus and the levels of SOD and GPx.

CONCLUSIONS

Our study is the first to assess CN and OFC together in OCD patients using 3 T MR, investigating the relationship between neurometabolite concentrations and oxidative stress parameters. The negative correlation we observed between NAA/Cr levels and SOD and GPx in the caudate nucleus suggests that increased oxidative stress in this brain region in OCD patients may contribute to impaired neuronal integration and functionality.

Oxidative Stress is a New Avenue for Treatment of Neuropsychiatric Disorders: Hype of Hope?

The biochemical integrity of the brain is critical in maintaining normal central nervous system (CNS) functions. One of the factors that plays an important role in causing biochemical impairment of the brain is known as oxidative stress. Oxidative stress is generally defined as the excessive formation of free radicals relative to antioxidant defenses. The brain is particularly susceptible to oxidative stress because of its high oxygen consumption and lipid-rich content. Therefore, oxidative stress damage is associated with abnormal CNS function. Psychiatric disorders are debilitating diseases. The underlying pathophysiology of psychiatric disorders is poorly defined and may involve the interplay of numerous clinical factors and mechanistic mechanisms. Considerable evidence suggests that oxidative stress plays a complex role in several neuropsychiatric disorders, including anxiety, bipolar disorder, depression, obsessivecompulsive disorder, panic disorder, and schizophrenia. To address these issues, we reviewed the literature and considered the role of oxidative stress as one of the first pathological changes in the course of neuropsychiatric disorders, which should receive more attention in future research.

The relation of optical coherence tomography findings with oxidative stress parameters in patients with bipolar disorder and unaffected first-degree relatives

BACKGROUND

We aimed to evaluate the optical coherence tomography(OCT) findings and oxidative stress parameters in patients with bipolar disorder(BD) and their unaffected first-degree relatives(FDRs) and to explore OCT findings and oxidative stress parameters as potential endophenotype candidates.

METHODS

Fifty patients with BD, 40 FDRs of BD, and 50 healthy controls(HCs) were included. OCT was performed to measure peripapillary retinal nerve fiber layer(RNFL), ganglion cell layer(GCL), inner plexiform layer(IPL), central macular, and minimum foveal thicknesses(CMT and MFT), choroidal thickness(ChT). 4-hydroxy-2-nonenal(HNE), total thiol(TT), native thiol(NT), total oxidant status(TOS), total antioxidant status(TAS), disulfide(DIS) and oxidative stress index(OSI) were measured from serum samples.

RESULTS

TOS was higher patients with BD and FDRs than HCs (p < .001 and p = .012, respectively). OSI, DIS, HNE levels were higher patients with BD and FDRs than HCs (p < .001). TAS, TT, NT levels were lower patients and FDRs than HCs (p < .001). MFT of patients was thinner than HCs (p = .001). CMT of patients was thinner than HCs (p = .006); the same trend was observed in FDRs but did not reach the statistical significance level (p = .07). The groups did not differ on RNFL and choroidal thickness or GCL and IPL volume.

LIMITATIONS

Evaluation of only a few retinal layers.

CONCLUSIONS

TOS, TAS, OSI, TT, NT, DIS, HNE can be useful endophenotype biomarkers in BD. Among the OCT findings, CMT was determined as the closest parameter to being an endophenotype biomarker. Our study corroborates that oxidative stress parameters are more effective than OCT findings in endophenotype studies.

Are there differences in oxidative stress and inflammatory processes between the autogenous and reactive subtypes of obsessive-compulsive disorder? A controlled cross-sectional study

Objective:

To date, no study has investigated whether autogenous and reactive obsessive-compulsive disorder (OCD) types are different entities in terms of oxidative stress and inflammatory processes. The aim of this study is to compare them in terms of these features.

Methods:

The study was conducted in subjects with reactive OCD (n=19), autogenous OCD (n=14), and a control group (n=17). All participants were non-smokers. Sociodemographic data were collected and the Yale-Brown Obsessive-Compulsive Scale (Y-BOCS), Beck Anxiety Inventory (BAI), Beck Depression Inventory (BDI), Obsessive Beliefs Questionnaire (OBQ), and Overvalued Ideas Scale (OVIS) were administered. High-sensitivity C-reactive protein (hs-CRP), interleukin-6 (IL-6), interleukin-10 (IL-10), paraoxonase (PON1), total oxidant status (TOS), and total antioxidant status (TAS) were measured.

Results:

There were no significant differences in TAS, TOS, or oxidative stress index (OSI) between the OCD and control groups. PON1 and hs-CRP levels were higher in the OCD group, whereas IL-6 and IL-10 levels were lower. Comparison across the three groups revealed no differences in TAS, TOS, OSI, or PON1 levels; however, hs-CRP was significantly higher while IL-6 and IL-10 were significantly lower in the reactive group compared to controls.

Conclusion:

Our results show that, although inflammatory processes may play a role in OCD, the autogenous and reactive subtypes do not differ from each other in these respects. The classification of OCD into autogenous and reactive subtypes should be reevaluated.

Increased Production of the Potent Oxidant Peroxynitrite in the Serum of Obsessive-Compulsive Disorder Patients

Background: There is growing evidence that oxidative stress may play a principal role in the etiology of psychiatric disorders, such as obsessive-compulsive disorder (OCD). The potent oxidant peroxynitrite (ONOO-) is the final yield of rapid reaction nitric oxide (NO) and superoxide anions. Objectives: The present study aimed to investigate whether serum peroxynitrite levels in patients with OCD disorder can be used as an oxidative biomarker Methods: Twenty-one patients with freshly diagnosed OCD and not using any drugs and 19 healthy volunteers were enrolled in this study. Serum peroxynitrite levels were measured in the control and OCD groups. Results: Serum peroxynitrite values in patients with newly diagnosed OCD were significantly increased compared to the control group (7.968 ± 2.576 µmol/L in patients and 4.983 ± 1.300 µmol/L in the control) and were significantly correlated with Yale-Brown Obsession Compulsion Scale scores. However, they were not significantly different between male and female groups. Conclusions: Our findings revealed a correlation between increased peroxynitrite level and OCD. Serum peroxynitrite level may be considered an oxidative biomarker for OCD patients in the future. It seems that using drugs with antioxidant properties can be used for the prevention of further damage by oxidants in the treatment of OCD patients.

Targeting Xanthine Oxidase by Natural Products as a Therapeutic Approach for Mental Disorders

Mental disorders comprise diverse human pathologies, including depression, bipolar affective disorder, schizophrenia, and dementia that affect millions of people around the world. The causes of mental disorders are unclear, but growing evidence suggests that oxidative stress and the purine/adenosine system play a key role in their development and progression. Xanthine oxidase (XO) is a flavoprotein enzyme essential for the catalysis of the oxidative hydroxylation of purines -hypoxanthine and xanthine- to generate uric acid. As a consequence of the oxidative reaction of XO, reactive oxygen species (ROS) such as superoxide and hydrogen peroxide are produced and, further, contribute to the pathogenesis of mental disorders. Altered XO activity has been associated with free radical-mediated neurotoxicity inducing cell damage and inflammation. Diverse studies reported a direct association between an increased activity of XO and diverse mental diseases including depression or schizophrenia. Small-molecule inhibitors, such as the well-known allopurinol, and dietary flavonoids, can modulate the XO activity and subsequent ROS production. In the present work, we review the available literature on XO inhibition by small molecules and their potential therapeutic application in mental disorders. In addition, we discuss the chemistry and molecular mechanism of XO inhibitors, as well as the use of structure-based and computational methods to design specific inhibitors with the capability of modulating XO activity.

The Psychopharmacology of Obsessive-Compulsive Disorder: A Preclinical Roadmap

This review evaluates current knowledge about obsessive-compulsive disorder (OCD), with the goal of providing a roadmap for future directions in research on the psychopharmacology of the disorder. It first addresses issues in the description and diagnosis of OCD, including the structure, measurement, and appropriate description of the disorder and issues of differential diagnosis. Current pharmacotherapies for OCD are then reviewed, including monotherapy with serotonin reuptake inhibitors and augmentation with antipsychotic medication and with psychologic treatment. Neuromodulatory therapies for OCD are also described, including psychosurgery, deep brain stimulation, and noninvasive brain stimulation. Psychotherapies for OCD are then reviewed, focusing on behavior therapy, including exposure and response prevention and cognitive therapy, and the efficacy of these interventions is discussed, touching on issues such as the timing of sessions, the adjunctive role of pharmacotherapy, and the underlying mechanisms. Next, current research on the neurobiology of OCD is examined, including work probing the role of various neurotransmitters and other endogenous processes and etiology as clues to the neurobiological fault that may underlie OCD. A new perspective on preclinical research is advanced, using the Research Domain Criteria to propose an adaptationist viewpoint that regards OCD as the dysfunction of a normal motivational system. A systems-design approach introduces the security motivation system (SMS) theory of OCD as a framework for research. Finally, a new perspective on psychopharmacological research for OCD is advanced, exploring three approaches: boosting infrastructure facilities of the brain, facilitating psychotherapeutic relearning, and targeting specific pathways of the SMS network to fix deficient SMS shut-down processes. SIGNIFICANCE STATEMENT: A significant proportion of patients with obsessive-compulsive disorder (OCD) do not achieve remission with current treatments, indicating the need for innovations in psychopharmacology for the disorder. OCD may be conceptualized as the dysfunction of a normal, special motivation system that evolved to manage the prospect of potential danger. This perspective, together with a wide-ranging review of the literature, suggests novel directions for psychopharmacological research, including boosting support systems of the brain, facilitating relearning that occurs in psychotherapy, and targeting specific pathways in the brain that provide deficient stopping processes in OCD.

A Psycho-Behavioral Perspective on Modelling Obsessive-Compulsive Disorder (OCD) in Animals: The Role of Context

Obsessive-compulsive disorder is a heterogeneous and debilitating condition, characterized by intrusive thoughts and compulsive repetition. Animal models of OCD are important tools that have the potential to contribute significantly to our understanding of the condition. Although there is consensus that pre-clinical models are valuable in elucidating the underlying neurobiology in psychiatric disorders, the current paper attempts to prompt ideas on how interpretation of animal behavior can be expanded upon to more effectively converge with the human disorder. Successful outcomes in psychopharmacology involve rational design and synthesis of novel compounds and their testing in well-designed animal models. As part of a special journal issue on OCD, this paper will 1) review the psychobehavioral aspects of OCD that are of importance on how the above ideas can be articulated, 2) briefly elaborate on general issues that are important for the development of animal models of OCD, with a particular focus on the role and importance of context, 3) propose why translational progress may often be less than ideal, 4) highlight some of the significant contributions afforded by animal models to advance understanding, and 5) conclude by identifying novel behavioral constructs for future investigations that may contribute to the face, predictive and construct validity of OCD animal models. We base these targets on an integrative approach to face and construct validity, and note that the issue of treatment-resistance in the clinical context should receive attention in current animal models of OCD.

Increased serum thioredoxin levels are not correlated with executive functions in children with attention deficit hyperactivity disorder

The first step of this study aims to determine whether thioredoxin (Trx) has a potential role in attention deficit hyperactivity disorder (ADHD) by measuring serum Trx levels in children with ADHD. In the second step, this study aims to reveal whether there is any relationship between Trx and executive functions. This is the first study investigating the serum levels of Trx in children with ADHD. This study sample included 45 patients diagnosed with ADHD and 30 healthy controls. Conners Teacher Rating Scale (CTRS) and Behavior Rating Inventory of Executive Function (BRIEF) are used to evaluate ADHD presentation, severity and executive functions, respectively. Trx levels were measured using an enzyme-linked immunosorbent assay (ELISA) kit. Significantly higher Trx levels were found in children with ADHD. No significant correlations were found between serum Trx levels and executive functions for controls or ADHD group; although hyperactive/impulsive ADHD presentation showed positive correlations with some subdomains of executive function. Serum Trx levels and disease severity, measured by CTRS, showed non-significant correlations. This study may be the first step in the study of the role played by Trx and oxidative stress in ADHD, further research is needed to support these preliminary findings.

Oxidative and nitrosative stress markers in obsessive-compulsive disorder: a systematic review and meta-analysis

OBJECTIVE

Obsessive-compulsive disorder (OCD) is a chronic, prevalent, and highly impairing psychiatric illness. Although the pathophysiology of OCD remains unknown, pathways involved in oxidative and nitrosative stress (O&NS) have been implicated. The present study aims to systematically review the literature for quantitative evidence that patients with OCD have altered measures of blood O&NS markers.

METHODS

Independent random-effects meta-analyses using standardized mean differences were conducted to assess each marker separately. Additionally, data from multiple markers were pooled together in a meta-analysis for measures of oxidant activity and another for measures of antioxidant activity.

RESULTS

Thirteen studies met inclusion criteria, involving 433 OCD patients and 459 controls. Eleven blood O&NS markers were eligible for independent quantitative analyses. We found that, in OCD patients, the oxidant markers 8-hydroxydeoxyguanosine and malondialdehyde, and the antioxidants glutathione peroxidase and superoxide dismutase, were significantly increased while total antioxidant status, vitamin C, and vitamin E were significantly decreased, when comparing with controls. Regarding pooled meta-analyses, we found a statistically significant increase in oxidant markers, but non-significant results regarding antioxidant markers.

CONCLUSIONS

Our meta-analysis suggests that OCD patients have a systemic oxidative imbalance that is not adequately buffered by the antioxidant system. Additional studies are needed in order to support this association.

8-F2-isoprostane, thioredoxin and thioredoxin reductase levels in children with obsessive-compulsive disorder

PURPOSE

Accumulating data demonstrate that oxidative stress may play a crucial role in obsessive-compulsive disorder (OCD). This study aimed to investigate the role of 8-F2-isoprostane, thioredoxin (Trx), and thioredoxin reductase (TrxR) in children with OCD.

MATERIALS AND METHODS

Thirty-three drug-free children with OCD and 35 healthy controls were included in this study. The severity of OCD symptoms was assessed via the Children's Yale Brown Obsessive-Compulsive Scale. The severity of anxiety levels was determined through the Screen for Child Anxiety-Related Emotional Disorders. Plasma levels of 8-F2-isoprostane, Trx, and TrxR were measured using commercial enzyme-linked immunosorbent assay kits.

RESULTS

Plasma 8-F2-isoprostane, Trx, and TrxR levels did not show any significant differences between patient and control groups. There were no significant correlations between plasma levels of these antioxidants and severity of OCD.

CONCLUSIONS

Findings of this study did not support the involvement of oxidative stress in the etiology of childhood OCD.

The anxiolytic effects of atorvastatin and simvastatin on dietary-induced increase in homocysteine levels in rats

The aim of this study was to evaluate the effects of atorvastatin and simvastatin on behavioral manifestations that followed hyperhomocysteinemia induced by special dietary protocols enriched in methionine and deficient in B vitamins (B6, B9, B12) by means of alterations in anxiety levels in rats. Simultaneously, we investigated the alterations of oxidative stress markers in rat hippocampus induced by applied dietary protocols. Furthermore, considering the well-known antioxidant properties of statins, we attempted to assess their impact on major markers of oxidative stress and their possible beneficial role on anxiety-like behavior effect in rats. The 4-week-old male Wistar albino rats were divided (eight per group) according to basic dietary protocols: standard chow, methionine-enriched, and methionine-enriched vitamins B (B6, B9, B12) deficient. Each dietary protocol (30 days) included groups with atorvastatin (3 mg/kg/day i.p.) and simvastatin (5 mg/kg/day i.p.). The behavioral testing was performed in the open field and elevated plus maze tests. Parameters of oxidative stress (index of lipid peroxidation, superoxide dismutase, catalase activity, glutathione) were determined in hippocampal tissue samples following decapitation after anesthesia. Methionine-load dietary protocols induced increased oxidative stress in rat hippocampus, which was accompanied by anxiogenic behavioral manifestations. The methionine-enriched diet with restricted vitamins B intake induced more pronounced anxiogenic effect, as well as increased oxidative stress compared to the methionine-load diet with normal vitamins B content. Simultaneous administration of statins showed beneficial effects by means of both decreased parameters of oxidative stress and attenuation of anxiety. The results obtained with simvastatin were more convincible compared to atorvastatin.

Peromyscus maniculatus bairdii as a naturalistic mammalian model of obsessive-compulsive disorder: current status and future challenges

Obsessive-compulsive disorder (OCD) is a prevalent and debilitating condition, characterized by intrusive thoughts and repetitive behavior. Animal models of OCD arguably have the potential to contribute to our understanding of the condition. Deer mice (Permomyscus maniculatus bairdii) are characterized by stereotypic behavior which is reminiscent of OCD symptomology, and which may serve as a naturalistic animal model of this disorder. Moreover, a range of deer mouse repetitive behaviors may be representative of different compulsive-like phenotypes. This paper will review work on deer mouse behavior, and evaluate the extent to which this serves as a valid and useful model of OCD. We argue that findings over the past decade indicate that the deer mouse model has face, construct and predictive validity.

Obsessive-compulsive disorder: Insights from animal models

Research with animal models of obsessive-compulsive disorder (OCD) shows the following: (1) Optogenetic studies in mice provide evidence for a plausible cause-effect relation between increased activity in cortico-basal ganglia-thalamo-cortical (CBGTC) circuits and OCD by demonstrating the induction of compulsive behavior with the experimental manipulation of the CBGTC circuit. (2) Parallel use of several animal models is a fruitful paradigm to examine the mechanisms of treatment effects of deep brain stimulation in distinct OCD endophenotypes. (3) Features of spontaneous behavior in deer mice constitute a rich platform to investigate the neurobiology of OCD, social ramifications of a compulsive phenotype, and test novel drugs. (4) Studies in animal models for psychiatric disorders comorbid with OCD suggest comorbidity may involve shared neural circuits controlling expression of compulsive behavior. (5) Analysis of compulsive behavior into its constitutive components provides evidence from an animal model for a motivational perspective on OCD. (6) Methods of behavioral analysis in an animal model translate to dissection of compulsive rituals in OCD patients, leading to diagnostic tests.

Oxidative status and prolidase activities in generalized anxiety disorder

OBJECTIVE

Prolidase (Pro), an intracellular enzyme necessary for collagen turnover, matrix remodelling and cell growth has been shown to be related to Oxidative Stress (OS). To our knowledge, serum Pro activity in generalized anxiety disorder (GAD) has not been documented yet. In this study, we aimed to evaluate OS and its relation with Pro activity in patients diagnosed with GAD.

METHOD

Thirty untreated GAD patients and 30 healthy controls were included in the study. Blood samples were collected from all subjects to quantify total oxidant status (TOS), total antioxidant status (TAS) and Pro activity. Oxidative stress index (OSI), the ratio of TOS to TAS, is calculated to evaluate the balance between antioxidants and oxidants. Hamilton Anxiety Rating Scale (HARS) was used to determine the anxiety levels of all subjects.

RESULTS

GAD group demonstrated statistically significantly higher TOS, OSI and Pro levels, when compared with the control group (t=2.947, p=0.005; t=2.874, p=0.006; and t=9.396, p<0.001 respectively). HARS scores were found to be positively correlated with TOS, OSI and Pro levels (p=0.008, r=0.338; p=0.008, r=0.339; and p<0.001, r=0.751 respectively).

CONCLUSION

The degree of severity of OS is correlated with the levels of Pro. Thus, Pro might be the target enzyme, promising to be a marker for the follow-up of GAD patients. To the best of our knowledge, this study is the first to report a significant relation between Pro activity and GAD.

Evaluation of Paraoxonase, Arylesterase and Malondialdehyde Levels in Schizophrenia Patients Taking Typical, Atypical and Combined Antipsychotic Treatment

Objective

Human serum paraoxonase (PON1) prevents lipids from peroxidation and functions as an antioxidant mechanism. Malonyldialdehyde (MDA) is the final product of lipid peroxidation and can be used as an indicator of oxidative stress. The aim of this study was to investigate PON1, MDA, and arylesterase (ARY) levels in schizophrenic patients who are taking typical, atypical, or combined (typical and atypical) antipsychotic drug treatment, with respect to those of healthy controls.

Methods

We evaluated 41 patients (11 taking typical antipsychotics, 19 taking atypical antipsychotics, 11 taking combined anti-psychotics) and 43 healthy controls.

Results

MDA levels were higher in schizophrenic patients taking typical antipsychotics compared with healthy controls (p=0.001). ARY levels were higher in patients taking atypical antipsychotics compared with healthy controls (p=0.005). PON1 activity was similar in all groups.

Conclusion

Our results indicate that treatment with typical antipsychotic drugs could be related to increased MDA levels; and antipsychotic medication may increase PON1 levels in schizophrenic patients.

Changes of Nitric Oxide and Peroxynitrite Serum Levels during Drug Therapy in Patients with Obsessive-Compulsive Disorder

Objectives. Some studies have shown that increased nitric oxide (NO) concentrations may be associated with obsessive-compulsive disorder (OCD). In a few animal researches, enhanced synthesis of NO had reversed the effect of selective serotonin reuptake inhibitors (SSRIs). The present study tries to find the effect of treatment with SSRIs on NO serum levels and its product peroxynitrite. Patients and Methods. Patients diagnosed with OCD who are candidates of receiving SSRIs entered this study. Two blood samples were taken from subjects, prior to drug therapy and after the patients had shown some improvements due to their regimen. Serum NO and peroxynitrite levels were measured and their correlation with SSRI use was assessed. Results. 31 patients completed this study. Mean concentrations of NO and peroxynitrite prior to drug therapy were 28.63 ± 16.9 and 5.73 ± 2.5 μmol/L, respectively. These values were 18.87 ± 7.55 and 2.15 ± 0.94 μmol/L at the second blood test. With p values < 0.05, these differences were considered significant. Conclusion. Patients, who showed improvement of OCD symptoms after a mean duration of SSRI monotherapy of 3.531 ± 0.64 months, had lower values of NO and peroxynitrite in their sera compared to their levels prior to therapy. Such results can be helpful in finding a predictive factor of response to therapy and augmentation therapy with future drugs that target NO synthesis.

Altered lipid peroxidation markers are related to post-traumatic stress disorder (PTSD) and not trauma itself in earthquake survivors

The traumatic life events, including earthquakes, war, and interpersonal conflicts, cause a cascade of psychological and biological changes known as post-traumatic stress disorder (PTSD). Malondialdehyde (MDA) is a reliable marker of lipid peroxidation, and paraoxonase is a known antioxidant enzyme. The aims of this study were to investigate the relationship between earthquake trauma, PTSD effects on oxidative stress and the levels of serum paraoxonase 1 (PON1) enzyme activity, and levels of serum MDA. The study was carried out on three groups called: the PTSD group, the traumatized with earthquake exercise group, and healthy control group, which contained 32, 31, and 38 individuals, respectively. Serum MDA levels and PON1 enzyme activities from all participants were measured, and the results were compared across all groups. There were no significant differences between the PTSD patients and non-PTSD earthquake survivors in terms of the study variables. The mean PON1 enzyme activity from PTSD patients was significantly lower, while the mean MDA level was significantly higher than that of the healthy control group (p < 0.01 for both measurements). Similarly, earthquake survivors who did not develop PTSD showed higher MDA levels and lower PON1 activity when compared to healthy controls. However, the differences between these groups did not reach a statistically significant level. Increased MDA level and decreased PON1 activity measured in PTSD patients after earthquake and may suggest increased oxidative stress in these patients. The nonsignificant trends that are observed in lipid peroxidation markers of earthquake survivors may indicate higher impact of PTSD development on these markers than trauma itself. For example, PTSD diagnosis seems to add to the effect of trauma on serum MDA levels and PON1 enzyme activity. Thus, serum MDA levels and PON1 enzyme activity may serve as biochemical markers of PTSD diagnosis.

DNA damage and antioxidants in treatment naïve children with obsessive-compulsive disorder

The current study aimed to investigate whether serum antioxidant levels and DNA damage differ between the children and adolescents with Obsessive Compulsive Disorder (OCD) and healthy controls. The study included 31 children (Male/Female, 22/9; age range 7-17 years), with treatment naïve OCD diagnosed according to Diagnostic and Statistical Manual of Mental Disorders-V (DSM-V) and 28 age- and gender-matched healthy control subjects. Children's Yale Brown Obsession Compulsion Scale (CY-BOC) was applied to the children. Glutathione peroxidase (GPx), superoxide dismutase (SOD), coenzyme Q (CoQ), and 8-Hydroxy-2-Deoxyguanosine (8-OHdG) were all measured by the enzyme-linked immunosorbent assay method. GPx, CoQ and 8-OHdG levels were found to be significantly higher in the OCD group, compared to the control group (p=0.010, p=0.034, p=0.010, respectively); however, no significant difference was found in the SOD levels between two groups (p=0.10). There were no correlations between the CY-BOC scores, depression scores, duration of the disease and biochemical parameters (p>0.05, for all). Children with OCD were found to have higher antioxidant levels and oxidative DNA damage. The findings of this study support the role of oxidative stress in the pathogenesis of OCD. In this regard, any possible effect of adding antioxidants to conventional treatment can be investigated.

Increased oxidative stress in children with attention deficit hyperactivity disorder

OBJECTIVES

The purpose of this study was to investigate oxidative stress in children with attention deficit hyperactivity disorder (ADHD).

METHODS

Total oxidant status (TOS), total antioxidant status (TAS), paraxonase-1 (PON-1) and arylesterase (ARE) activity were measured in 76 children (44 boys, 32 girls) diagnosed with ADHD according to the DSM-IV and 78 healthy children (46 boys, 32 girls).

RESULTS

Age and sex were similar between the groups (P > 0.05). TOS and the oxidative stress index (OSI) were higher in the patient group than the control group (P < 0.001). PON-1 (P = 0.002), ARE (P = 0.010) activity and TAS (P < 0.001) were lower in the patient group than the control group.

DISCUSSION

We found decreased PON-1, ARE activity and TAS, and increased TOS and OSI in children with ADHD. Our study showed that there is significantly increased oxidative stress in children with ADHD.

Evaluation of oxidative metabolism and oxidative DNA damage in patients with obsessive-compulsive disorder

AIMS

There are limited published data about the role of oxidative stress in the pathophysiology of obsessive-compulsive disorder (OCD). In addition, oxidative stress and oxidative DNA damage have not been investigated together in OCD. In this study, we aimed to evaluate oxidative stress and oxidative DNA damage in patients with OCD.

METHODS

Forty-two patients with OCD who were diagnosed in the Psychiatry Clinic of Gaziantep University and 38 healthy volunteers were enrolled in the study. Serum 8-hydroxideoxiguanosine (8-OHdG), total antioxidant status, total oxidant status evaluation and oxidative stress index calculation were conducted in Gaziantep University Biochemical Laboratory.

RESULTS

There were no significant differences in the total antioxidant status, total oxidant status and oxidative stress index levels between the patients and control group. However, 8-OHdG levels were significantly higher in OCD patients than controls (P = 0.022). In addition, 8-OHdG levels were significantly lower in patients who took treatment than in patients who were newly diagnosed (P = 0.016).

CONCLUSIONS

In our study, we found that oxidative DNA damage increased in OCD patients even though oxidative stress was normal. In addition, DNA damage was lower in patients who were treated compared to those without treatment.

Evaluation of oxidant, antioxidant, and S100B levels in patients with conversion disorder

INTRODUCTION

Various psychodynamic, neurobiological, genetic, and sociocultural factors are believed to be involved in the etiology of conversion disorder (CD). Oxidative metabolism has been shown to deteriorate in association with many health problems and psychiatric disorders. We evaluated oxidative metabolism and S100B levels in the context of this multifactorial disease.

METHODS

Thirty-seven patients with CD (25 females and 12 males) and 42 healthy volunteers (21 females and 21 males), all matched for age and sex, were included in this study. The total oxidant status, total antioxidant status, oxidative stress index, and S100B levels were compared between the two groups.

RESULTS

The total oxidant status, oxidative stress index, and S100B levels were significantly higher in patients with CD than in the control group, whereas the total antioxidant status was significantly lower.

CONCLUSION

CD is associated with deterioration of oxidative metabolism and increased neuronal damage.

Evaluation of oxidative and antioxidative parameters in generalized anxiety disorder

Generalized anxiety disorder (GAD) is a prevalent psychiatric disorder. The exact causes of GAD still unknown, in addition to neurochemical and neuroanatomic disorders, genetic and environmental factors are discussed in etiology. In our study we aimed to evaluate the oxidative metabolism's status and investigate the role of oxidative metabolites in GAD. Blood samples were taken from enrolled subjects in appropriate way and total antioxidant status (TAS), total oxidant status (TOS), and oxidative stress index (OSI) were studied in Harran University Biochemistry Labs. Results were compared between groups. The patients' TOS and OSI levels were significantly higher than control group. The patients' TAS levels were significantly lower than controls'. According to our findings, oxidative stress mechanism might have a role in GAD pathophysiology. In the future, total antioxidants may be used as a biologic marker in GAD etiology but more research is needed.

Oxidative markers of Myeloperoxidase and Catalase and their diagnostic performance in bipolar disorder

BACKGROUND

Recent researches suggest oxidative stress and generalized inflammatory state to be associated with bipolar I disorder (BID). Our aim is to evaluate Myeloperoxidase (MPO) and Catalase (CAT) activities in BID.

METHODS

73 BID patients and 73 healthy controls were enrolled. Patients were classified into manic, depressive and euthymic state. Serum MPO and CAT were measured in both patients and controls.

RESULTS

CAT activity was significantly lower in controls than manic, depressive and euthymics (p<0.001). MPO activity was significantly higher in controls compared to euthymics (p=0.007) and it was significantly higher in depressives compared to euthymics (p=0.023). CAT was negatively and MPO was positively correlated with disease duration in overall the patients. Positive Predictive Value was 94.5% and Negative Predictive Value was 100% above the cutoff point for CAT activity.

CONCLUSION

MPO and CAT activities are impaired in BID, which may be associated with oxidative stress and inflammation.

Serum total oxidant and antioxidant status in earthquake survivors with post-traumatic stress disorder

OBJECTIVE

Oxidative stress has been shown to play an important role in the pathogenesis of post-traumatic stress disorder (PTSD). Although there are some studies on oxidative stress and PTSD, there is no report available on the serum total oxidant and antioxidant status in earthquake survivors with PTSD. Therefore, this study aimed to investigate the serum total oxidant and antioxidant status in earthquake survivors with chronic PTSD.

MATERIAL AND METHODS

The study group included 45 earthquake survivors with PTSD and 40 earthquake survivors without PTSD. The oxidative status was determined using the total antioxidant status and total oxidant status (TOS) measurements and by calculating the oxidative stress index (OSI).

RESULTS

There were no statistically significant differences in the total antioxidant status, TOS, or OSI when comparing individuals with and without PTSD (all, p>0.05). There were no correlations between Clinician-Administered PTSD Scale scores and oxidant and antioxidant stress markers (all, p>0.05).

CONCLUSIONS

Our results suggest that the total oxidant and antioxidant status may not affect earthquake survivors with PTSD. This is the first study to evaluate the oxidative status in earthquake survivors with PTSD. Further studies are necessary to confirm these findings.

Clinical trials of N-acetylcysteine in psychiatry and neurology: A systematic review

N-acetylcysteine (NAC) is recognized for its role in acetaminophen overdose and as a mucolytic. Over the past decade, there has been growing evidence for the use of NAC in treating psychiatric and neurological disorders, considering its role in attenuating pathophysiological processes associated with these disorders, including oxidative stress, apoptosis, mitochondrial dysfunction, neuroinflammation and glutamate and dopamine dysregulation. In this systematic review we find favorable evidence for the use of NAC in several psychiatric and neurological disorders, particularly autism, Alzheimer's disease, cocaine and cannabis addiction, bipolar disorder, depression, trichotillomania, nail biting, skin picking, obsessive-compulsive disorder, schizophrenia, drug-induced neuropathy and progressive myoclonic epilepsy. Disorders such as anxiety, attention deficit hyperactivity disorder and mild traumatic brain injury have preliminary evidence and require larger confirmatory studies while current evidence does not support the use of NAC in gambling, methamphetamine and nicotine addictions and amyotrophic lateral sclerosis. Overall, NAC treatment appears to be safe and tolerable. Further well designed, larger controlled trials are needed for specific psychiatric and neurological disorders where the evidence is favorable.

Oxidative stress in children and adolescents with anxiety disorders

BACKGROUND

Anxiety disorders are common in children and adolescents, and they can significantly impair quality of life. Genetic, neurobiological, neurochemical, and psychological factors are believed to play a role in the etiopathogenesis of anxiety disorders. Recent evidence suggests that the pathophysiology of anxiety disorders may be associated with oxidative stress. In this study, we investigated whether there are associations between children with anxiety disorders and total oxidant/antioxidant status.

METHODS

The experimental group consisted of 40 patients (children and adolescents) with anxiety disorders. An age- and gender-matched control group composed of 35 healthy subjects was also assessed. Venous blood samples were collected and total antioxidative status (TAS), total oxidative status (TOS), and the oxidative stress index (OSI) were determined.

RESULTS

Both the TOS and the OSI of the experimental group were significantly higher than those of the control group. There were no significant differences in TAS between the experimental and control groups.

LIMITATIONS

The main limitation of our study was the small sample size.

CONCLUSIONS

This study suggests that oxidative balance is impaired in children with anxiety disorders. Oxidative stress may play a role in the etiopathogenesis of anxiety disorders, and TOS may be a useful diagnostic tool in this context.

Lipid peroxidation markers in children with anxiety disorders and their diagnostic implications

OBJECTIVE

Numerous factors, including genetic, neurobiological, neurochemical, and psychological factors, are thought to be involved in the development of anxiety disorders. The latest findings show that the pathophysiology of anxiety disorders might be associated with oxidative stress and lipid peroxidation; however, no studies have so far investigated lipid peroxidation markers in children with anxiety disorders. Serum levels of lipid hydroperoxide (LOOH) are a reliable marker of lipid peroxidation. Paraoxonase and arylesterase are two enzymes that protect against such peroxidation, and might also be diagnostic markers. In this study, we investigated whether there are associations between anxiety disorders and lipid peroxidation markers in children, and assessed the diagnostic performance of these markers.

METHODS

The study group consisted of 37 patients (children and adolescents) with anxiety disorders. A control group, matched for age and gender, was composed of 36 healthy subjects. Venous blood samples were collected, and LOOH levels and paraoxonase and arylesterase activity were measured.

RESULTS

LOOH levels were significantly higher in the anxiety disorders group than in the control group. There were no significant differences in paraoxonase or arylesterase activities between the patient and the control groups.

DISCUSSION

Lipid peroxidation or oxidative damage might play a role in the aetiopathogenesis of anxiety disorders. LOOH may be a potential biological marker for anxiety disorders in children.

Oxidative imbalance in child and adolescent patients with obsessive compulsive disorder

Various psychological, social, genetic and biochemical factors are thought to be involved in etiology of obsessive-compulsive disorder (OCD). To the best of our knowledge there are no studies investigating the effects of free radicals in children and adolescents with OCD. This study evaluated total oxidant and antioxidant status, oxidative stress index, and arylesterase and paraoxonase activity in children and adolescents with OCD. The study included 28 patients diagnosed with OCD and 36 healthy children as an age- and sex-matched control group. Their serum total oxidant status (TOS) and total antioxidant status (TAS) were measured and the oxidative stress index (OSI) was calculated. Although serum TOS and OSI values in the OCD patients were significantly higher than those in the control group (p = 0.008, p < 0.001, respectively), TAS and paraxonase activity were significantly lower ( p < 0.001 for both). However, no statistically significant difference in arylesterase activity was found (p > 0.05). The increase in oxidative status and decrease in antioxidants in patients with OCD demonstrate that oxidative stress may have an important role in the pathophysiology of the disease. It has been suggested that drugs that contain antioxidants should be added to conventional pharmacotherapy during follow-up.

Reduced PON1 enzymatic activity and increased lipid hydroperoxide levels that point out oxidative stress in generalized anxiety disorder

In recent years, there has been an increasing focus on generalized anxiety disorder (GAD) which is one of the most prevalent mental disorders in general population. Psychological, genetic, neurobiological, and neurochemical factors are believed to play role in the etiopathogenesis of GAD. The role of oxidative stress, as a neurochemical cause, in various anxiety disorders has been studied in recent years; however, it has not been thoroughly studied in GAD, yet. In this paper, we aimed to evaluate the serum levels of lipid hydroperoxide (LOOH), paraoxonase, and arylesterase in GAD patients without any co-morbid psychiatric disorders and investigate their diagnostic performance. Blood samples were collected from 40 GAD patients and 40 healthy control subjects to measure their serum LOOH levels, arylesterase and paraoxonase activities. Obtained results have been compared between groups and receiver operating characteristic (ROC) curve has been drawn for diagnostic performance of measured biochemical markers. Positive and negative predictive values have been estimated where appropriate. Mean LOOH level of the GAD patients was significantly higher than that of control subjects (t=-5.49, p<0.001), whereas, mean paraoxonase activity was lower in these patients (t=3.056, p=0.03). GAD could be predicted for LOOH level over 7.740 μmol/l with 92.5% positive predictive value and 92% negative predictive value. Increased LOOH level and decreased paraoxonase activity of GAD patients may suggest increased lipid peroxidation and oxidative stress in these patients. LOOH levels may be a state marker for diagnosing GAD.

Decreased serum sulphydryl levels as a sign of increased oxidative stress in generalized anxiety disorder

OBJECTIVE

In recent years, many published studies have focused on the relationship between oxidative stress and psychiatric disorders. However, studies in generalized anxiety disorder (GAD) are few despite relatively high prevalence rates. In an attempt to fill this gap in the literature we aimed to measure serum levels of free sulphydryl, an important member of antioxidant defense mechanisms, of the patients with GAD.

METHODS

A total of 35 (23 female, 12 male) GAD patients without any other co-morbid medical or psychiatric disorder and 35 (23 female, 12 male) healthy controls have been included in the study. Disease severity of the patients were quantified by using the Hamilton Anxiety Rating Scale (HAM-A). Serum free sulphydryl group levels of patients and healthy controls were measured in an appropriate way.

RESULTS

Mean level of serum sulphydryl groups was significantly lower in the patient group. There was a negative correlation between their level and the disease duration. However, they did not show any significant correlation with the disease severity.

CONCLUSION

Decreased serum sulphydryl level observed in pure GAD patients suggests an increased oxidative stress in these patients. Well designed future researches are needed to replicate our findings and to test the implications of the present study.

The promise of N-acetylcysteine in neuropsychiatry

N-Acetylcysteine (NAC) targets a diverse array of factors germane to the pathophysiology of multiple neuropsychiatric disorders including glutamatergic transmission, the antioxidant glutathione, neurotrophins, apoptosis, mitochondrial function, and inflammatory pathways. This review summarises the areas where the mechanisms of action of NAC overlap with known pathophysiological elements, and offers a précis of current literature regarding the use of NAC in disorders including cocaine, cannabis, and smoking addictions, Alzheimer's and Parkinson's diseases, autism, compulsive and grooming disorders, schizophrenia, depression, and bipolar disorder. There are positive trials of NAC in all these disorders, and although many of these require replication and are methodologically preliminary, this makes it one of the most promising drug candidates in neuropsychiatric disorders. The efficacy pattern of NAC interestingly shows little respect for the current diagnostic systems. Its benign tolerability profile, its action on multiple operative pathways, and the emergence of positive trial data make it an important target to investigate.

A critical review of magnetic resonance spectroscopy studies of obsessive-compulsive disorder

Functional neuroimaging studies have converged to suggest that cortico-striatal-thalamo-cortical (CSTC) circuit dysfunction is a core pathophysiologic feature of obsessive-compulsive disorder (OCD). Now, complementary approaches examining regional neurochemistry are beginning to yield additional insights with regard to the neurobiology of aberrant CSTC circuitry in OCD. In particular, proton magnetic resonance spectroscopy, which allows for the in vivo quantification of various neurochemicals in the CSTC circuit and other brain regions, has recently been used extensively in studies of OCD patients. In this review, we summarize the diverse and often seemingly inconsistent findings of these studies, consider methodological factors that might help to explain these inconsistencies, and discuss several convergent findings that tentatively seem to be emerging. We conclude with suggestions for possible future proton magnetic resonance spectroscopy studies in OCD.

Plasma total antioxidant status and cognitive impairments in schizophrenia

Oxidative stress-induced damage to neurons may contribute to cognitive deficits during aging and in neurodegenerative disorders. Schizophrenia has a range of cognitive deficits that may evolve from oxidative stress, and this study examines this association of oxidative stress with cognitive deficits in schizophrenia. We recruited 296 chronic schizophrenia patients and 181 healthy control subjects and examined the Repeatable Battery for the Assessment of Neuropsychological Status (RBANS) and plasma total antioxidant status (TAS) in both groups. Schizophrenia symptoms were assessed using the positive and negative syndrome scale (PANSS). Our results showed that TAS levels were significantly lower in patients than controls (179.6 ± 81.0 U/ml vs. 194.8 ± 46.0 U/ml, p<0.05). Cognitive scores on the RBANS and nearly all of its five subscales (all p<0.001) except for the Visuospatial/Constructional index (p>0.05) were significantly lower in schizophrenia patients than normal controls. For the patients, TAS was inversely associated with some domains of cognitive deficits in schizophrenia, such as Attention and Immediate Memory. Our findings suggest that oxidative stress may be involved in the pathophysiology of schizophrenia, and its associated cognitive impairment.

Antioxidants as antidepressants: fact or fiction?

Depression is a medical condition with a complex biological pattern of aetiology, involving genetic and epigenetic factors, along with different environmental stressors. Recent evidence suggests that oxidative stress processes might play a relevant role in the pathogenic mechanism(s) underlying many major psychiatric disorders, including depression. Reactive oxygen and nitrogen species have been shown to modulate levels and activity of noradrenaline (norepinephrine), serotonin, dopamine and glutamate, the principal neurotransmitters involved in the neurobiology of depression. Major depression has been associated with lowered concentrations of several endogenous antioxidant compounds, such as vitamin E, zinc and coenzyme Q10, or enzymes, such as glutathione peroxidase, and with an impairment of the total antioxidant status. These observations introduce new potential targets for the development of therapeutic interventions based on antioxidant compounds. The present review focuses on the possible role of oxidative stress processes in the pathogenesis of depression. The therapeutic potential of antioxidant compounds as a co-adjuvant treatment to conventional antidepressants is discussed. For instance, N-acetyl-cysteine has been shown to have a significant benefit on depressive symptoms in a randomized placebo-controlled trial. Additionally, curcumin, the yellow pigment of curry, has been shown to strongly interfere with neuronal redox homeostasis in the CNS and to possess antidepressant activity in various animal models of depression, also thanks to its ability to inhibit monoamine oxidases. There is an urgent need to develop better tolerated and more effective treatments for depressive disorders and several antioxidant treatments appear promising and deserve further study.

Oxidative stress in children with attention deficit hyperactivity disorder

OBJECTIVE

The aim of this study was to investigate oxidative stress in ADHD children.

DESIGN AND METHODS

Levels of oxidant parameters malondialdehyde (MDA), 8-hydroxy-2'-deoxyguanosine (8-OHDG), advanced oxidation protein products (AOPP) and antioxidant parameters paraoxonase (PON1) and thiol levels were measured in thirty children with ADHD (27 boys, 3 girls) who were firstly diagnosed according to DSM-IV and thirty healthy children (18 boys, 12 girls) aged 6-12 years.

RESULTS

The levels of the oxidant parameters MDA and 8-OHDG were statistically significantly lower in ADHD children compared to the controls. We did not find a significant difference between the groups regarding AOPP, PON1, and thiol levels.

CONCLUSION

We found low levels of some oxidants and no difference of antioxidant parameters in ADHD children. Our study points out that there may not be a direct relationship between oxidative stress and ADHD.

Changes in oxidative stress and cellular immunity serum markers in attention-deficit/hyperactivity disorder

AIMS

Attention-deficit/hyperactivity disorder (ADHD) is a developmental disorder with an etiopathogeny not fully understood. According to the prevailing view, the main factors contributing to the disorder are prefrontal dopamine deficiency and central dopaminergic dysfunction, but the factors/mechanisms involved in the brain dysfunction and its consequences are not well known. We suggest that changes in oxidative metabolism and cellular immunity may be involved. In this study, we aimed to investigate whether there are associations between ADHD and changes in serum levels of nitric oxide synthase (NOS), xanthine oxidase (XO), glutathione S-transferase (GST) and paraoxonase-1 (PON-1) activities, which are important markers of oxidative stress, and adenosine deaminase (ADA) activity, marker of cellular immunity.

METHODS

The study sample consisted of 35 child or adolescent patients diagnosed with ADHD according to DSM-IV-TR criteria. Thirty-five healthy subjects were also included in the study as controls. Venous blood samples were collected, and NOS, XO, GST, PON-1 and ADA activities were measured.

RESULTS

NOS, XO and ADA activities of the patients were significantly higher than those of the controls. GST and PON-1 activities of the patients were significantly lower than those of the controls.

CONCLUSIONS

Changes in oxidative metabolism and cellular immunity may have a role in the etiopathogenesis of ADHD.

Evaluation of total oxidative status in adult attention deficit hyperactivity disorder and its diagnostic implications

Adult Attention Deficit Hyperactivity Disorder (A-ADHD) is one of the psychiatric disorders which awareness is growing. The exact causes of A-ADHD are still unknown. In addition to neurochemical and neuroanatomic disorders, genetic and environmental factors are discussed in its etiology. In our study, we aimed to evaluate the oxidative status of A-ADHD patients and investigate whether oxidative metabolites can be used as diagnostic tools or not in A-ADHD. Blood samples were taken from enrolled 50 A-ADHD patients and 31 controls in appropriate way and Total Antioxidative Status (TAS), Total Oxidative Status (TOS), and Oxidative Stress Index (OSI) were studied in Harran University Biochemistry Labs. Results were compared between groups and ROC curve was drawn in order to evaluate diagnostic performances. Patients' TAS, TOS and OSI were significantly higher than controls. There was not a significant difference between comorbid cases and only A-ADHD patients in terms of measured values. A-ADHD can be predicted for TOS over 9.8575 μmol H(2)O(2) Eqv./L level with 86% positive predictive value and %100 negative predictive value. In A-ADHD, oxidative balance is impaired. High antioxidant levels may be compensatory against the oxidant increase. Oxidative parameters may be used in A-ADHD diagnosis.

Amelioration of Chemical-Induced Skin Carcinogenesis by Aegle marmelos, an Indian Medicinal Plant, Fruit Extract

Chemoprevention is a novel approach to study the anti-initiating and anti-tumor-promoting efficacy of medicinal plants and their active principles. The present study investigated the chemopreventive potential of Aegle marmelos fruit extract in 7,12-dimethylbenz[a]anthracene-induced skin carcinogenesis and its influence on oxidative stress and the antioxidant defense system. The oral administration of A marmelos at 100 mg/kg body weight/day during peri-initiational, postinitiational, and peri- & postinitiational phases of papillomagenesis showed significant reduction in tumor incidence, tumor yield, tumor burden, and cumulative number of papillomas when compared with carcinogen-treated control. The average latent period significantly increased (7.88 weeks; control group) to 9.45, 11.11, and 11.54 weeks in different A marmelos extract (AME) experimental groups. Enzyme analysis of skin and liver showed a significant elevation in antioxidant parameters such as superoxide dismutase, catalase, glutathione, and vitamin C in AME-treated groups when compared with the carcinogen-treated control. The elevated level of lipid peroxidation in the positive control was significantly inhibited by AME administration. These results indicate that AME has the potential to reduce chemical-induced skin papillomas by enhancing the antioxidant defense system.

Reduced plasma total antioxidant status in first-episode drug-naive patients with schizophrenia

Excessive free radical production leading to oxidative stress may be involved in the pathophysiology of schizophrenia. Determination of total antioxidant status (TAS) provides an index of the sum of activities of all antioxidants. However, there have been few systematic studies to examine the relationship between TAS levels and psychopathology in first-episode and drug-naive patients with schizophrenia. TAS levels were determined in the plasma of 60 never-medicated first-episode patients with schizophrenia and 68 healthy control subjects. The schizophrenia symptomatology and the depressive symptoms were assessed by the positive and negative syndrome scale (PANSS) and the Hamilton rating scale for depression (HAMD). The results showed that TAS levels were significantly lower in first-episode patients with schizophrenia than in healthy control subjects (159.8 ± 45.8 U/ml vs 211.4 ± 46.8 U/ml, F=39.5, df=1, 126, p < 0.001). A trend toward significant inverse correlation between TAS levels and PANSS negative subscore was observed (r = 0.25, df=60, p = 0.06). Our results suggest that oxidative stress occurs in an early course of schizophrenia and may have an important role in pathogenesis and perhaps, negative symptomatology of schizophrenia.

Cortico-striatal oxidative status, dopamine turnover and relation with stereotypy in the deer mouse

The deer mouse presents with spontaneous stereotypic movements that resemble the repetitive behaviours of obsessive-compulsive disorder (OCD), and demonstrates a selective response to serotonin reuptake inhibitors. OCD has been linked to altered redox status and since increased dopamine signalling can promote stereotypies as well as oxidative stress, we investigated whether the severity of deer mouse stereotypy may be associated with altered dopamine turnover and cortico-striatal redox status. Deer mice were separated into high (HSB), low (LSB) and non-stereotypy (NS) groups. Frontal cortical and striatal dopamine, 3,4-dihydroxyphenylacetic acid (DOPAC) and homovanillic acid (HVA), as well as superoxide dismutase (SOD) activity, reduced (GSH) and oxidised (GSSG) glutathione and glutathione redox index, were analysed as markers for regional dopamine turnover and oxidative stress, respectively. Dopamine and its metabolites and SOD activity did not differ across the stereotypy groups. Significantly reduced GSH and GSSG and increased glutathione redox index were only observed in the frontal cortex of HSB animals. Frontal cortical GSH and GSSG were inversely correlated while glutathione redox index was positively correlated with stereotypy. Deer mouse stereotypy is thus characterised by a deficient glutathione system in the frontal cortex but not striatum, and provides a therapeutic rationale for using glutathione-active antioxidants in OCD. The evidence for a primary frontal lesion has importance for future OCD research.

N-acetylcysteine in psychiatry: current therapeutic evidence and potential mechanisms of action

There is an expanding field of research investigating the benefits of alternatives to current pharmacological therapies in psychiatry. N-acetylcysteine (NAC) is emerging as a useful agent in the treatment of psychiatric disorders. Like many therapies, the clinical origins of NAC are far removed from its current use in psychiatry. Whereas the mechanisms of NAC are only beginning to be understood, it is likely that NAC is exerting benefits beyond being a precursor to the antioxidant, glutathione, modulating glutamatergic, neurotropic and inflammatory pathways. This review outlines the current literature regarding the use of NAC in disorders including addiction, compulsive and grooming disorders, schizophrenia and bipolar disorder. N-acetylcysteine has shown promising results in populations with these disorders, including those in whom treatment efficacy has previously been limited. The therapeutic potential of this acetylated amino acid is beginning to emerge in the field of psychiatric research.