In a double-blind, randomized and placebo-controlled trial, adjuvant allopurinol improved symptoms of mania in in-patients suffering from bipolar disorder

Uric Acid as a Biomarker for Mood Disorders: A Comparative Study of Blood Uric Acid Levels Correlating With the Symptom Severity and Treatment Response

Background Bipolar affective disorder (BPAD) and major depressive disorder (MDD) are two mood disorders whose pathophysiology may involve the purinergic system. Elevated uric acid levels, associated with this system, can impact various behaviors in individuals affected by these conditions. In addition to genetic predisposition, blood uric acid levels can be impacted by various factors, including metabolic syndrome, the consumption of psychoactive medications, and other underlying kidney conditions such as gout. Objective The study aims to investigate the relationship between blood uric acid levels and mental health conditions, specifically BPAD subtypes (manic and depressive) and MDD. The study also examines changes in blood uric acid levels following treatment and evaluates the effectiveness of different treatment approaches in reducing uric acid levels. Methodology To be eligible to participate, individuals must have a confirmed diagnosis of BPAD (manic or depressive type) or MDD, according to the International Classification of Diseases (ICD-10). Blood uric acid levels were measured at both baseline and follow-up assessments. Symptoms were assessed weekly using standardized rating scales (Young Mania Rating Scale (YMRS) and Hamilton Rating Scale for Depression (HAM-D)) until treatment response was achieved, which was defined as a 50% reduction in initial scores on both scales. We used ANOVA to examine the differences among the three patient groups and paired sample t-tests to examine the changes in means before and after treatment conditions. Results A significant positive correlation was found between the severity of illness and serum uric acid levels across all three patient groups: those with BPAD-mania, BPAD-depression, and MDD. Notably, patients with BPAD-mania patients had significantly higher serum uric acid levels (5.2±0.9 mg/dL) compared to those with BPAD-depression (4.8±1.0 mg/dL) and MDD (4.0±1.1 mg/dL). After treatment, all patient groups exhibited a decrease in serum uric acid levels. The reduction in serum uric acid levels was pronounced in all patient groups, with decreases of 3.1±0.8 mg/dL in patients with BPAD-mania, 3.1±0.9 mg/dL in those with BPAD-depression, and 3.5±1.1 mg/dL in those with MDD. The study showed that the reduction in serum uric acid levels was significantly correlated with the severity of illness in patients with BPAD-mania, but not in those with BPAD-depression or MDD. Furthermore, the study found that treatment with lithium carbonate, sodium valproate, or carbamazepine was equally effective in reducing serum uric acid levels, regardless of the mood stabilizer used. Conclusion The study supports that dysfunction in the purine system might play a significant role in the development and progression of BPAD, suggesting that this phenomenon is not solely due to chronicity or medication exposure. This study also introduces a fresh perspective on the underlying biological processes that contribute to the development of BPAD and also sheds light on new treatment regimens targeting uric acid reduction in treating patients with bipolar disorder.

Antimanic-like effect of dipyridamole in the methylphenidate-induced hyperlocomotion

BACKGROUND

Adenosinergic system has been implicated in the pathophysiology of bipolar disorder and drugs that affect adenosine neurotransmission have shown some efficacy as add-on therapy in manic patients.

OBJECTIVE

Thus, the aim of the present study was to screen adenosinergic drugs for antimanic-like effect in methylphenidate (MPH)-induced hyperlocomotion in mice.

METHODS

Male and female Swiss mice received a single allopurinol (50 and 200 mg/kg, ip), dipyridamole (20 mg/kg, ip), or inosine (50 mg/kg, ip) administration before an acute MPH challenge (5 mg/kg, sc). In experiments with repeated treatment, male mice received a daily administration of allopurinol (25 and 50 mg/kg, ip), dipyridamole (20 mg/kg, ip), or inosine (50 mg/kg, ip) for 14 days. Finally, pretreatment with aminophylline (2 mg/kg, sc), an unspecific adenosine receptor antagonist, was used to evaluate a putative adenosinergic mediation. Locomotor activity was measured in the automated activity chamber for 20 min.

RESULTS

Acute and repeated dipyridamole reduced the increase in locomotor activity induced by MPH, while allopurinol and inosine had no effect. Aminophylline blocked the effect of dipyridamole in MPH-induced hyperlocomotion.

CONCLUSION

The present results suggest that dipyridamole may have an antimanic-like effect through adenosine receptors and reinforce the proposal that the adenosine system may be an interesting target for new antimanic drugs.

Salivary uric acid across child development and associations with weight, height, and body mass index

Introduction

Obesity during childhood is a serious and growing chronic disease with consequences for lifelong health. In an effort to advance research into the preclinical indicators of pediatric obesity, we examined longitudinal assessments of uric acid concentrations in saliva among a cohort of healthy children from age 6-months to 12-years (n's per assessment range from 294 to 727).

Methods

Using data from a subsample of participants from the Family Life Project (an Environmental influences on Child Health Outcomes Program cohort), we: (1) characterized salivary uric acid (sUA) concentrations from infancy to early adolescence by sex and race; (2) assessed changes in sUA levels across development; and (3) evaluated associations between sUA concentrations and measures of child weight, height, and body mass index (BMI). Across four assessments conducted at 6-, 24-, 90-, and 154-months of age, 2,000 saliva samples were assayed for UA from 781 participants (217 participants had sUA data at all assessments).

Results

There were no significant differences in sUA concentrations by sex at any assessment, and differences in sUA concentrations between White and non-White children varied by age. At the 90- and 154-month assessments, sUA concentrations were positively correlated with measures of child weight, height, and BMI (90-month: weight- ρ(610) = 0.13, p < 0.01; height- ρ(607) = 0.10, p < 0.05; BMI- ρ(604) = 0.13, p < 0.01; 154-month: weight- ρ(723) = 0.18, p < 0.0001; height- ρ(721) = 0.10, p < 0.01; BMI- ρ(721) = 0.17, p < 0.0001). Group based trajectory modeling identified two groups of children in our sample with distinct patterns of sUA developmental change. The majority (72%) of participants showed no significant changes in sUA across time ("Stable" group), while 28% showed increases in sUA across childhood with steep increases from the 90- to 154-month assessments ("Increasing" group). Children in the Increasing group exhibited higher sUA concentrations at all assessments (6-month: t(215) = -5.71, p < 0.001; 24-month: t(215) = -2.89, p < 0.01; 90-month: t(215) = -3.89, p < 0.001; 154-month: t(215) = -19.28, p < 0.001) and higher weight at the 24- and 90-month assessments (24-month: t(214) = -2.37, p < 0.05; 90-month: t(214) = -2.73, p < 0.01).

Discussion

Our findings support the potential utility of sUA as a novel, minimally-invasive biomarker that may help advance understanding of the mechanisms underlying obesity as well as further surveillance and monitoring efforts for pediatric obesity on a large-scale.

Non-canonical pathways in the pathophysiology and therapeutics of bipolar disorder

Bipolar disorder (BD) is characterized by extreme mood swings ranging from manic/hypomanic to depressive episodes. The severity, duration, and frequency of these episodes can vary widely between individuals, significantly impacting quality of life. Individuals with BD spend almost half their lives experiencing mood symptoms, especially depression, as well as associated clinical dimensions such as anhedonia, fatigue, suicidality, anxiety, and neurovegetative symptoms. Persistent mood symptoms have been associated with premature mortality, accelerated aging, and elevated prevalence of treatment-resistant depression. Recent efforts have expanded our understanding of the neurobiology of BD and the downstream targets that may help track clinical outcomes and drug development. However, as a polygenic disorder, the neurobiology of BD is complex and involves biological changes in several organelles and downstream targets (pre-, post-, and extra-synaptic), including mitochondrial dysfunction, oxidative stress, altered monoaminergic and glutamatergic systems, lower neurotrophic factor levels, and changes in immune-inflammatory systems. The field has thus moved toward identifying more precise neurobiological targets that, in turn, may help develop personalized approaches and more reliable biomarkers for treatment prediction. Diverse pharmacological and non-pharmacological approaches targeting neurobiological pathways other than neurotransmission have also been tested in mood disorders. This article reviews different neurobiological targets and pathophysiological findings in non-canonical pathways in BD that may offer opportunities to support drug development and identify new, clinically relevant biological mechanisms. These include: neuroinflammation; mitochondrial function; calcium channels; oxidative stress; the glycogen synthase kinase-3 (GSK3) pathway; protein kinase C (PKC); brain-derived neurotrophic factor (BDNF); histone deacetylase (HDAC); and the purinergic signaling pathway.

Lorazepam use during clinical trials of adults with bipolar mania episodes

Background

Lorazepam has commonly been prescribed to reduce agitation during bipolar 1 mania trials. Its use has varied considerably by trial methodology and in clinical practice.

Methods

The extent and amount of lorazepam treatment was recorded and analyzed from available brief, controlled trials of acute bipolar mania and in clinical reports in adults.

Results

In 3-week, placebo-controlled clinical trials (n = 19), most manic subjects (79%) were treated with lorazepam to reduce agitation. This treatment was most prominent during the antimanic drug wash-out phase that preceded placebo-controlled trials. Doses of lorazepam administered during the first 7-10 days of the pre-trial and the early trial phases averaged 2.2 mg/day. These doses were one-third the lorazepam/clonazepam doses administered during placebo-controlled, non-washout trials. Far higher benzodiazepine doses for manic agitation were noted in emergency department reports. Intake enrollment was strikingly restricted only in placebo-controlled trials that used pretrial drug wash-out.

Conclusions

Medication treatment conclusions from placebo-controlled, drug washout trials are not representative of clinical treatment for acute bipolar mania.

Association between uric acid and cognitive dysfunction: A cross-sectional study with newly diagnosed, drug-naïve with bipolar disorder

BACKGROUND

Cognitive impairment is one of the major symptoms of individuals with bipolar disorder (BD). Purine system disorders may play an important role in cognitive dysfunction. So far, the relationship between cognitive deficits and purinergic metabolism in BD has been seldom discussed in previous studies. This study aims to explore its relevance and potential biological mechanisms.

METHODS

In this cross-sectional study, 205 first time diagnosed drug-naive individuals with BD and 97 healthy volunteers were recruited. The uric acid(UA) level was measured using automatic biochemical analyzer, and cognitive function was assessed by Repeatable Battery for the Assessment of Neuropsychological Status (RBANS) and Stroop color-word test. In addition, general information and clinical symptoms were collected and evaluated.

RESULTS

In this study, the UA level of BD group (U = 8475.000, p = 0.038) was found to be significantly higher than that of the healthy controls, but the scores of RBANS (t = -11.302, p < 0.001) and Stroop color-word test (t = -6.962, p < 0.001) were significantly lower than that of the healthy controls. In gender subgroup analysis, females had lower UA level and higher RBANS scores. In correlation analysis, the cognitive function of individuals with BD was found to present a significant negative correlation with UA level in attention (r = -0.23, p = 0.001) and delayed memory(r = -0.16, p = 0.022).

LIMITATIONS

This is a cross-sectional design.

CONCLUSION

Elevated UA levels may be a potential mechanism of cognitive impairment in BD. This provides a new possible strategy for the prevention and treatment of cognitive impairment in BD.

Allopurinol, dipyridamole and calcium channel blockers in the treatment of bipolar disorder - A nationwide cohort study

BACKGROUND

Improved treatments for bipolar disorder (BD) are needed. Drug repurposing aims to find novel targets for drugs that have been used for other indications. This study investigated the risk of psychiatric hospitalization associated with use of calcium-channel blockers (CCBs; dihydropyridines, diltiazem, verapamil) and adenosine modulators (allopurinol, dipyridamole) in BD in within-individual design.

METHODS

Individuals diagnosed with BD (ICD-10: F30-F31) were identified from the inpatient, specialized outpatient, sickness absence, and disability pension registers during 1996-2018 in Finland (N = 60,045). The main outcome was hospitalization due to affective symptoms (ICD-10: F30-F39). Within-individual models in stratified Cox regression were used and adjusted hazard ratios (aHR) with 95 % confidence intervals (CIs) reported.

RESULTS

Use of CCBs was associated with a decreased risk of hospitalization due to affective symptoms (aHR 0.83, 95 % CI 0.78-0.88) when all CCBs were analyzed together. Of specific CCBs, use of diltiazem (0.71, 0.55-0.91) and dihydropyridines (0.83, 0.78-0.89) were associated with a decreased risk but verapamil was not (0.93, 0.73-1.19). Use of adenosine modulators in general was associated with a decreased risk of hospitalizations due to affective symptoms (0.87, 0.79-0.96). Both allopurinol (0.85, 0.74-0.97) and dipyridamole (0.89, 0.78-1.00) were associated with a marginally decreased risk. Thiazide diuretic use as a negative control was not associated with the risk of hospitalization due to affective symptoms (0.97, 0.83-1.13).

LIMITATIONS

Due to the observational nature of this study, causation cannot be confirmed.

CONCLUSIONS

Dihydropyridines and diltiazem were associated with a decreased risk of psychiatric hospitalization in bipolar disorder. Results for allopurinol and dipyridamole were inconclusive.

Influence of adjuvant clonidine on mania, sleep disturbances and cognitive performance - Results from a double-blind and placebo-controlled randomized study in individuals with bipolar I disorder during their manic phase

BACKGROUND

While the favorable effect of adjuvant clonidine in the treatment of acute mania has been observed already about 40 years ago, this line of treatment has not been further investigated. Here, we resumed this topic, and we tested the effect of adjuvant clonidine, an antihypertensive stimulating the alpha-₂ central adrenergic receptor, on symptoms of mania, cognitive performance, and subjective sleep. To this end, we performed a randomized, double-blind and placebo-controlled clinical trial among inpatients with bipolar disorder I during their acute phase of mania.

METHODS

A total of 70 inpatients (mean age: 37.40 years; 15.7% females) with diagnosed bipolar disorder I and during their acute manic phase were randomly assigned either to the adjuvant clonidine (0.2 mg/d to a maximum of 0.6 mg/d) or to the placebo condition. Standard medication was lithium at therapeutic dosages. At baseline, participants completed a series of self-rating questionnaires covering sociodemographic information and subjective sleep. Subjective sleep was re-assessed 24 days later at the end of the study. Experts rated participants' acute state of mania with the Young Mania Rating Scale at baseline and at day 12 and day 24. Participants' cognitive performance was assessed at baseline and at day 24 at the end of the study.

RESULTS

Over time, mania scores significantly decreased (large effect size), but more so in the clonidine condition, compared to the placebo condition (medium effect size). Likewise, over time, subjective sleep improved (large effect size), but more so in the clonidine, compared to the placebo condition (medium effect size). Over time, cognitive performance improved (medium effect size), irrespective from the study condition.

CONCLUSIONS

Compared to placebo, adjuvant clonidine to lithium improved symptoms of mania, as rated by experts', and subjective sleep quality. Adjuvant clonidine had no further favorable (or detrimental) impact on cognitive performance.

Adenosine Receptors in Neuropsychiatric Disorders: Fine Regulators of Neurotransmission and Potential Therapeutic Targets

Adenosine exerts an important role in the modulation of central nervous system (CNS) activity. Through the interaction with four G-protein coupled receptor (GPCR) subtypes, adenosine subtly regulates neurotransmission, interfering with the dopaminergic, glutamatergic, noradrenergic, serotoninergic, and endocannabinoid systems. The inhibitory and facilitating actions of adenosine on neurotransmission are mainly mediated by A₁ and A_2A adenosine receptors (ARs), respectively. Given their role in the CNS, ARs are promising therapeutic targets for neuropsychiatric disorders where altered neurotransmission represents the most likely etiological hypothesis. Activating or blocking ARs with specific pharmacological agents could therefore restore the balance of altered neurotransmitter systems, providing the rationale for the potential treatment of these highly debilitating conditions. In this review, we summarize and discuss the most relevant studies concerning AR modulation in psychotic and mood disorders such as schizophrenia, bipolar disorders, depression, and anxiety, as well as neurodevelopment disorders such as autism spectrum disorder (ASD), fragile X syndrome (FXS), attention-deficit hyperactivity disorder (ADHD), and neuropsychiatric aspects of neurodegenerative disorders.

The Purinergic System as a Target for the Development of Treatments for Bipolar Disorder

The neurobiological and neurochemical mechanisms underlying the pathophysiology of bipolar disorder are complex and not yet fully understood. From circadian disruption to neuroinflammation, many pathways and signaling molecules are important contributors to bipolar disorder development, some specific to a disease subtype or a cycling episode. Pharmacological agents for bipolar disorder have shown only partial efficacy, including mood stabilizers and antipsychotics. The purinergic hypothesis for bipolar disorder emerges in this scenario as a promising target for further research and drug development, given its role in neurotransmission and neuroinflammation that results in behavioral and mood regulation. Here, we review the basic concepts of purinergic signaling in the central nervous system and its contribution to bipolar disorder pathophysiology. Allopurinol and novel P2X7 receptor antagonists are promising candidates for treating bipolar disorder. We further explore currently available pharmacotherapies and the emerging new purinergic targets for drug development in bipolar disorder.

Influence of Lisdexamfetamine Dimesylate on Early Ejaculation-Results from a Double-Blind Randomized Clinical Trial

BACKGROUND

Among male sexual dysfunctions, erectile dysfunction and early ejaculation have the highest prevalence rates. Here, we tested the influence of lisdexamfetamine dimesylate (Vyas®) on early ejaculation. To this end, we performed a double-blind randomized clinical trial among males with early ejaculation.

METHODS

A total of 46 males with early ejaculation (mean age: 35.23 years) and in stable marital relationships with regular weekly penile-vaginal intercourse were randomly assigned either to the lisdexamfetamine dimesylate condition (30 mg) or to the placebo condition. Compounds were taken about six hours before intended penile-vaginal intercourse. At baseline and four weeks later at the end of the study, participants completed a series of self-rating questionnaires covering early ejaculation. Female partners also rated participants' early ejaculation profile.

RESULTS

Compared to the placebo condition, dimensions of early ejaculation improved over time in the lisdexamfetamine condition, though improvements were also observed in the placebo condition.

CONCLUSIONS

Among male adults in stable marital relationships with regular weekly penile-vaginal intercourse, lisdexamfetamine dimesylate improved dimensions of early ejaculation. Given that improvements were also observed in the placebo condition, psychological factors such as increased attention to early ejaculation and favorable expectations of the compound should be considered.

Fructose and Uric Acid as Drivers of a Hyperactive Foraging Response: A Clue to Behavioral Disorders Associated with Impulsivity or Mania?

Several behavioral disorders, including attention deficit hyperactivity disorder (ADHD), bipolar disorder, and aggressive behaviors are linked with sugar intake and obesity. The reason(s) for this association has been unclear. Here we present a hypothesis supporting a role for fructose, a component of sugar and high fructose corn syrup (HFCS), and uric acid (a fructose metabolite), in increasing the risk for these behavioral disorders. Recent studies have shown that the reason fructose intake is strongly associated with development of metabolic syndrome is that fructose intake activates an evolutionary-based survival pathway that stimulates foraging behavior and the storage of energy as fat. While modest intake may aid animals that would like to store fat as a protective response from food shortage or starvation, we propose that high intake of sugar and HFCS causes a hyperactive foraging response that stimulates craving, impulsivity, risk taking and aggression that increases the risk for ADHD, bipolar disease and aggressive behavior. High glycemic carbohydrates and salty foods may also contribute as they can be converted to fructose in the body. Some studies suggest uric acid produced during fructose metabolism may mediate some of these effects. Chronic stimulation of the pathway could lead to desensitization of hedonic responses and induce depression. In conclusion, a hyperactive foraging response driven by high glycemic carbohydrates and sugars may contribute to affective disorders.

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.

Mental Comorbidity in Rheumatic Diseases

In this review, we summarise the most relevant studies in a PubMed Search term “mental disorders and rheumatic disease” in the last 15 years. Mental disorders such as depression and anxiety are common in people with rheumatic diseases. Treating these comorbidities can improve the patientʼs quality of life. The high prevalence of symptoms of psychiatric disorders is a challenge for rheumatologists, especially with regard to the differentiation of possible psychiatric components in rheumatological diseases. Screening for psychiatric problems in patients with rheumatic diseases should be evaluated as soon as possible, as these can have a major influence on the perception of pain and physical functioning status from the outset. Mental health disorders are seen as a risk factor for poor patient outcomes, as patients may not adhere to medical treatments. The potential side effects of biological agents can increase patient anxiety and affect adherence to therapy. Therefore, interdisciplinary care would be of great advantage in the treatment of rheumatic patients with psychological comorbidities.

Soft Drink Consumption and Mental Health in Adolescents: A Longitudinal Examination

PURPOSE

Previous studies showed associations between soft drink consumption and mental health problems in adolescents, but the direction of these effects is unknown. This study examines the hypotheses that soft drink consumption predicts aggression and depressive symptoms over time and that these mental health problems predict soft drink consumption.

METHODS

Interviews were conducted with 5,147 children and their caregivers from three sites at child ages 11, 13, and 16. At each time point, youth reported on their frequency of consuming soft drinks, aggressive behavior, and depressive symptoms. An autoregressive cross-lagged path model tested reciprocal relationships between soft drink consumption, aggressive behavior, and depressive symptoms over time.

RESULTS

More frequent consumption of soft drinks was associated with more aggressive behavior at each time point and depressive symptoms at ages 11 and 13 (r = .04 to .18, p ≤ .002). After adjusting for covariates and stability of each behavior over time, soft drink consumption at ages 11 and 13 predicted more aggressive behavior at the next time point (β = .08 and .06, p < .001). Aggressive behavior at age 13 also predicted more soft drink consumption at age 16 (β = .06, p = .002). Soft drink consumption at age 13 predicted fewer depressive symptoms (β = -.04, p = .007), but depressive symptoms did not predict soft drink consumption.

CONCLUSIONS

More frequent consumption of soft drinks may contribute to aggressive behavior in adolescents over time; there is some support for reciprocal relationships. There is no evidence for soft drink consumption contributing to adolescents' depression. Future research should examine longitudinal effects over shorter intervals.

Comparison of Serum Uric Acid in Major Depressive Disorder and Bipolar Disorder: a Retrospective Chart Review Study

BACKGROUND

Uric acid (UA) has been suggested as a possible biomarker of bipolar disorder (BD) in recent studies. We aimed to provide a clearer comparison of UA levels between BD and major depressive disorder (MDD).

METHODS

We retrospectively reviewed the medical chart records of psychiatric inpatients aged 19-60 years, whose main discharge diagnoses were either MDD or BD, with an admission between January 1, 2015 and December 31, 2018 at Seoul National University Hospital. Data such as sex, age, body mass index (BMI), medication usage, and serum UA levels were extracted. Patients with medical conditions or on medications that could influence UA levels were excluded. Age, sex, BMI, and psychiatric drug usage were considered in the comparison of serum UA between MDD and BD patients.

RESULTS

Our sample consisted of 142 MDD patients and 234 BD patients. The BD patients had significantly higher serum UA levels compared to the MDD patients, without accounting for other confounding variables (5.75 ± 1.56 mg/dL vs. 5.29 ± 1.59 mg/dL, P = 0.006). T-test comparisons between psychiatric medication users and non-users revealed that mood stabilizers and antipsychotics may be relevant confounding factors in our sample analysis. The likelihood of BD diagnosis was significantly correlated with higher UA levels (odds ratio, 1.410; 95% confidence interval, 1.150-1.728; P = 0.001) when accounting for sex, age, and BMI in the logistic regression analysis. Also, accounting for mood stabilizers or antipsychotics, the likelihood of BD diagnosis was still significantly correlated with higher UA levels.

CONCLUSION

Our study confirms that BD patients are significantly more likely to show higher serum UA levels than MDD patients. The high UA levels in BD point to purinergic dysfunction as an underlying mechanism that distinguishes BD from MDD. Further research is recommended to determine whether UA is a trait or a state marker and whether UA correlates with the symptoms and severity of BD.

Effect of Rivastigmine (Acetyl Cholinesterase Inhibitor) versus Placebo on Manic Episodes in Patients with Bipolar Disorders: Results from a Double Blind, Randomized, Placebo-Controlled Clinical Trial

BACKGROUND

To treat patients with bipolar disorders (BPD) during the acute phase, the standard procedure is to administer lithium or sodium valproate. To further optimize treatment, acetylcholinesterase inhibitors such as donepezil and galantamine have gained increased interest, though with conflicting results. In the present randomized, double-blind, placebo-controlled clinical trial, we investigated whether, and to what extent, adjuvant rivastigmine might improve symptoms of mania in patients with BPD during the acute manic phase.

METHODS

A total of 70 patients with BPD in an acute state of mania (mean age 33.8 years; 24% females) took part in this study. After a thorough clinical interview, standard treatment consisted of 20mg/kg/day of sodium valproate; next, patients were randomly assigned either to the adjuvant rivastigmine or to the placebo condition. The study duration was 24 days. The dose of rivastigmine was 1.5 mg for the first 7 days and 3 mg from day 8 to day 24. Experts blind to the patients' study condition rated patients' mania scores, symptom severity, and symptom improvements at baseline (except symptom improvements) and 4, 8, 12, and 24 days after the beginning of this study.

RESULTS

Symptoms of mania improved over time, but more so in the adjuvant rivastigmine compared to the placebo condition. Greater improvements were observed from day 8 on.

CONCLUSIONS

The pattern of results from the present randomized, placebo-controlled, double-blind study suggests that adjuvant rivastigmine, a cholinesterase inhibitor, improved symptoms of mania among a larger sample of inpatients with BPD and in the acute manic state. However, the improvements were modest, and the results should be replicated and above all balanced against side effects.

The CINP Guidelines on the Definition and Evidence-Based Interventions for Treatment-Resistant Bipolar Disorder

BACKGROUND

Resistant bipolar disorder is a major mental health problem related to significant disability and overall cost. The aim of the current study was to perform a systematic review of the literature concerning (1) the definition of treatment resistance in bipolar disorder, (2) its clinical and (3) neurobiological correlates, and (4) the evidence-based treatment options for treatment-resistant bipolar disorder and for eventually developing guidelines for the treatment of this condition.

MATERIALS AND METHODS

The PRISMA method was used to identify all published papers relevant to the definition of treatment resistance in bipolar disorder and the associated evidence-based treatment options. The MEDLINE was searched to April 22, 2018.

RESULTS

Criteria were developed for the identification of resistance in bipolar disorder concerning all phases. The search of the literature identified all published studies concerning treatment options. The data were classified according to strength, and separate guidelines regarding resistant acute mania, acute bipolar depression, and the maintenance phase were developed.

DISCUSSION

The definition of resistance in bipolar disorder is by itself difficult due to the complexity of the clinical picture, course, and treatment options. The current guidelines are the first, to our knowledge, developed specifically for the treatment of resistant bipolar disorder patients, and they also include an operationalized definition of treatment resistance. They were based on a thorough and deep search of the literature and utilize as much as possible an evidence-based approach.

Patients With Drug-Naive Bipolar Disorder in Remission After 8 Weeks of Treatment Had Decreased Serum Uric Acid Concentrations

Background: Evidence indicates that the serum concentration of uric acid (UA) in patients may relate both to the pathophysiology and therapeutics of bipolar disorder (BPD). The purpose of this study was to examine the changes and clinical significance of serum UA concentrations in first-episode manic patients suffering from BPD. Methods: Seventy-six drug-naive patients with first-episode bipolar mania and 76 age- and gender-matched healthy subjects were recruited. Young Mania Rating Scale and Hamilton Depression Rating Scale were used to assess clinical symptoms. We tested serum UA concentrations by sandwich enzyme-linked immunosorbent assay at baseline and at the end of 8-week treatment in BPD patients and in the control group. Results: After 8-week quetiapine and sodium valproate treatment, this study revealed that the serum UA concentrations in remitted patients were significantly lower than nonremitted patients; however, those remitted patients still had higher serum UA than healthy controls. We discovered that the baseline UA concentration was higher in nonremitted than remitted patients after 8 weeks of treatment. Finally, a positive association was found between serum UA and symptom relief in the first episode of manic disorder patients. Conclusion: Patients with first-episode BPD had high levels of serum UA, which responds to treatment mainly in remitted patients. Our results suggest that serum UA concentrations might present potentially a trait marker in bipolar patients.

New drug candidates for depression - a nationwide population-based study

OBJECTIVE

To investigate whether continued use of non-aspirin NSAID, low-dose aspirin, high-dose aspirin, statins, allopurinol and angiotensin agents decreases the rate of incident depression using Danish nationwide population-based registers.

METHODS

All persons in Denmark who purchased the exposure medications of interest between 1995 and 2015 and a random sample of 30% of the Danish population was included in the study. Two different outcome measures were included, (i) a diagnosis of depressive disorder at a psychiatric hospital as in-patient or out-patient and (ii) a combined measure of a diagnosis of depression or use of antidepressants.

RESULTS

A total of 1 576 253 subjects were exposed to one of the six drugs of interest during the exposure period from 2005 to 2015. Continued use of low-dose aspirin, statins, allopurinol and angiotensin agents was associated with a decreased rate of incident depression according to both outcome measures. Continued uses of non-aspirin NSAIDs as well as high-dose aspirin were associated with an increased rate of incident depression.

CONCLUSION

The findings support the potential of agents acting on inflammation and the stress response system in depression as well as the potential of population-based registers to systematically identify drugs with repurposing potential.

The validity, stability, and utility of measuring uric acid in saliva

AIM

Serum uric acid (UA) is associated with many health conditions, including kidney, cardiovascular, and metabolic disorders. We examined the validity and stability of salivary UA as a noninvasive measure of serum UA.

MATERIALS & METHODS

Using serum and salivary UA data from healthy adults (n = 99), we examined the UA serum-saliva correlation, and UA associations with adiponectin and C-reactive protein. Using longitudinal data from young adults (n = 182), we examined salivary UA stability.

RESULTS

We found robust positive serum-saliva correlations for UA. UA and adiponectin were inversely related in serum and saliva. Salivary UA was relatively stable; 62-66% of variance could be attributed to a latent trait-like component.

CONCLUSION

Salivary UA may be an important biomarker indexing health and disease risk.

An overview of pharmacotherapy for bipolar I disorder

INTRODUCTION

Bipolar I disorder (BD I) is complex with a chronic course that significantly impacts a sufferer's quality of life. As of right now, there are many available treatments that aim to rapidly treat manic or depressive episodes and stabilize mood. The purpose of this report is to provide an up-to-date comprehensive review of the available evidence-based trials of pharmacotherapy for the treatment of BD I.

AREAS COVERED

This paper reviews randomized active comparator-controlled or placebo-controlled trials evaluating the use of current pharmacotherapy in adults with BD I from phase III to clinical practice. Monotherapy and combination therapy for acute and long-term treatment were reviewed for this purpose.

EXPERT OPINION

There are many treatments available for BD mania; however, the depressive and stabilization phases of the illness remain a clinical challenge. Unfortunately, randomized controlled trials do not represent 'real world' patients, as their strict inclusion and exclusion criteria do not allow for different features sometimes present in patients to be considered. Research efforts must also focus on treating cognitive deficits, which adds to lower functional outcome. The authors believe that there is dire need for new, more targeted treatments in BD I, with a critical view of the side effects.

Allopurinol augmentation in acute mania: A meta-analysis of placebo-controlled trials

BACKGROUND

Allopurinol is a xanthine oxidase inhibitor commonly used in the treatment of gout. Recent studies have also shown its promise as an adjunctive treatment for manic episodes in bipolar 1 disorder, possibly through mechanisms involving the purinergic pathway. However, its efficacy across studies has been inconsistent, so we conducted a meta-analysis of the published controlled studies with the goal of determining the efficacy profile of allopurinol as an adjunctive treatment for mania in bipolar disorder.

METHODS

An online search was conducted using PubMed for placebo-controlled, randomized, double-blind, clinical trials (RCTs) using the terms "allopurinol," "bipolar," "mania," "manic," and "YMRS" and a meta-analysis was conducted in accordance with the Preferred Reporting Items for Systematic reviews and Meta-Analyses statement.

RESULTS

Five studies met the criteria for inclusion. Three of the five studies were inpatient treatments, one study was outpatient treatment, and one study had a mixture of both. All studies used allopurinol as an adjunct in treating acute mania in bipolar disorder subjects. Four of the studies showed efficacy in the primary outcome measure between allopurinol vs. placebo groups with significantly reduced YMRS scores while one showed no significant effect size between the allopurinol and placebo groups. The overall effect size for the four studies is d = 0.294. No significant difference in side effects were found between groups for any of the studies.

CONCLUSION

The data suggest that allopurinol may have some efficacy as an adjunct in reducing mania symptoms during acute manic episodes in patients with bipolar disorder. Adjunctive allopurinol efficacy may be related to the mood stabilizer used. Additional controlled trials with greater sample sizes, homogenous dosing, and consistent treatment modalities are needed to determine optimal clinical application.

Uric acid in major depressive and anxiety disorders

BACKGROUND

Uric acid has neuroprotective effects, owing to its antioxidant properties. Lowered antioxidant capacity, causing increased oxidative stress, may be involved in affective disorders and might be altered by antidepressants. This study investigated the association of plasma uric acid, the greatest contributor to blood antioxidant capacity, with major depressive disorder (MDD) and anxiety disorders.

METHODS

Data were from the Netherlands Study of Depression and Anxiety including patients with current (N = 1648), remitted (N = 609) MDD and/or anxiety disorders (of which N = 710 antidepressant users) and 618 controls. Diagnoses were established with the Composite International Diagnostic Interview. Symptom severity was assessed with the Inventory of Depressive Symptoms-Self Report, Beck Anxiety Inventory and Fear Questionnaire. Uric acid was measured in plasma. Analyses were adjusted for sociodemographic, health and lifestyle variables.

RESULTS

Plasma uric acid adjusted mean levels were lower in current MDD and/or anxiety disorder(s) (289μmol/l) compared to remitted disorders (298μmol/l, p < .001) and controls (299μmol/l, p < .001; Cohen's d .10). This finding was independent of antidepressant use. Depressive (β-.05, p = .0012), anxiety (β-.04, p = .009) and phobic (β-.03, p = .036) symptom severity, and symptom duration (β-.04, p = .009) were negatively associated with uric acid.

LIMITATIONS

Limitations include the lack of data on dietary intake which could be a potential confounding factor. From these cross-sectional findings, the association between uric acid and psychopathology cannot be inferred to be causal.

CONCLUSION

This large scale study finds plasma uric acid levels are lower in current, but not remitted, MDD and/or anxiety disorders, according to a dose-response gradient. This suggests the involvement of decreased antioxidant status in affective disorders, and points to their potential as an avenue for treatment.

Shared metabolic and immune-inflammatory, oxidative and nitrosative stress pathways in the metabolic syndrome and mood disorders

This review examines the shared immune-inflammatory, oxidative and nitrosative stress (IO&NS) and metabolic pathways underpinning metabolic syndrome (MetS), bipolar disorder (BD) and major depressive disorder (MDD). Shared pathways in both MetS and mood disorders are low grade inflammation, including increased levels of pro-inflammatory cytokines and acute phase proteins, increased lipid peroxidation with formation of malondialdehyde and oxidized low density lipoprotein cholesterol (LDL-c), hypernitrosylation, lowered levels of antioxidants, most importantly zinc and paraoxonase (PON1), increased bacterial translocation (leaky gut), increased atherogenic index of plasma and Castelli risk indices; and reduced levels of high-density lipoprotein (HDL-c) cholesterol. Insulin resistance is probably not a major factor associated with mood disorders. Given the high levels of IO&NS and metabolic dysregulation in BD and MDD and the high comorbidity with the atherogenic components of the MetS, mood disorders should be viewed as systemic neuro-IO&NS-metabolic disorders. The IO&NS-metabolic biomarkers may have prognostic value and may contribute to the development of novel treatments targeting neuro-immune, neuro-oxidative and neuro-nitrosative pathways.

Purinergic system dysfunctions in subjects with bipolar disorder: A comparative cross-sectional study

BACKGROUND

Subjects with bipolar mania may have increased uric acid levels, based on a purinergic system dysfunction with reduced neurotransmission of adenosine. We investigated whether there were differences in uric acid levels between individuals with bipolar disorder (in manic or depressive phases) and those with major depressive disorder.

METHODS

We conducted a cross-sectional study recruiting 128 subjects with bipolar disorder and 118 with major depressive disorder, admitted to a psychiatric inpatient unit. Standard demographic and clinical information were retrieved from electronic charts and relevant clinical records. Fasting serum values of uric acid, as well as metabolic (total cholesterol, triglycerides, and glycaemia), oxidative stress (albumin, bilirubin), and kidney function (creatinine), parameters, were collected.

RESULTS

Subjects with bipolar mania (5.27±1.63mg/dL), but not those with bipolar depression (4.89±1.94mg/dL), had higher levels of serum uric acid (p<0.05), as compared with individuals with major depressive disorder (4.59±1.62mg/dL). Relevant linear regression analyses, controlling for metabolic profile, oxidative stress markers, kidney function, and comorbid alcohol use disorder, showed a significant association between bipolar mania (p<0.01) and increased uric acid.

CONCLUSIONS

Findings of this study add evidence to the role of uric acid as state, rather than trait, marker in bipolar disorders. Explored, relevant, confounders do not seem to influence these results. The current study supports the hypothesis of a purinergic system dysfunction associated with manic phases of bipolar disorder.

The International College of Neuro-Psychopharmacology (CINP) Treatment Guidelines for Bipolar Disorder in Adults (CINP-BD-2017), Part 2: Review, Grading of the Evidence, and a Precise Algorithm

Background

The current paper includes a systematic search of the literature, a detailed presentation of the results, and a grading of treatment options in terms of efficacy and tolerability/safety.

Material and Methods

The PRISMA method was used in the literature search with the combination of the words 'bipolar,' 'manic,' 'mania,' 'manic depression,' and 'manic depressive' with 'randomized,' and 'algorithms' with 'mania,' 'manic,' 'bipolar,' 'manic-depressive,' or 'manic depression.' Relevant web pages and review articles were also reviewed.

Results

The current report is based on the analysis of 57 guideline papers and 531 published papers related to RCTs, reviews, posthoc, or meta-analysis papers to March 25, 2016. The specific treatment options for acute mania, mixed episodes, acute bipolar depression, maintenance phase, psychotic and mixed features, anxiety, and rapid cycling were evaluated with regards to efficacy. Existing treatment guidelines were also reviewed. Finally, Tables reflecting efficacy and recommendation levels were created that led to the development of a precise algorithm that still has to prove its feasibility in everyday clinical practice.

Conclusions

A systematic literature search was conducted on the pharmacological treatment of bipolar disorder to identify all relevant random controlled trials pertaining to all aspects of bipolar disorder and graded the data according to a predetermined method to develop a precise treatment algorithm for management of various phases of bipolar disorder. It is important to note that the some of the recommendations in the treatment algorithm were based on the secondary outcome data from posthoc analyses.

Allopurinol as add-on treatment for mania symptoms in bipolar disorder: systematic review and meta-analysis of randomised controlled trials

BACKGROUND

Since bipolar disorder seems to be associated with purinergic system dysfunction, allopurinol might be effective in treating symptoms of mania.

AIMS

To estimate the efficacy and tolerability of allopurinol as adjunctive treatment for mania symptoms in people with bipolar affective disorder.

METHOD

We conducted a systematic review and meta-analysis of randomised controlled trials (RCTs) comparing the effects of adjunctive allopurinol and placebo on mania symptom changes.

RESULTS

Five RCTs were included in the meta-analysis. Participants with allopurinol augmentation had a significantly greater decrease in mania symptoms than those with placebo (SMD = -0.34, P = 0.007), especially in people with the most severe forms of mania. Remission rates, although based on only two studies (n = 177), were significantly higher among individuals receiving allopurinol, whereas for discontinuation and side-effects no difference was found.

CONCLUSIONS

Our finding of a small to moderate effect size and overall low evidence for add-on allopurinol in reducing mania symptoms indicate that its use in routine practice needs further elucidation.

Peripheral adenosine levels in euthymic patients with bipolar disorder

Recent evidence points to the involvement of the purinergic signaling in the pathophysiology of bipolar disorder. The aim of this study was to assess the serum levels of adenosine and to evaluate its relation to functioning in 24 euthymic patients with bipolar disorder type I and in 25 matched healthy controls. Subjects were evaluated using the functioning assessment short test. Serum purine levels were measured by high pressure liquid chromatography. Our results show a decrease in serum adenosine levels in bipolar disorder patients compared with controls (t= -4.8, df= 43.96, p<0.001). Moreover, a significant negative correlation was found between patient adenosine levels and depression scale scores (r= -0.642, p= 0.001). Higher functional impairment was linked to lower levels of adenosine in patients (rho= -0.551, p= 0.008). Taken together, our results provide evidence for a purinergic imbalance in bipolar disorder, specifically an adenosinergic dysfunction. Our results also indicate a relation between adenosine levels and the functional impairment caused by the disorder, which could demonstrate a potential relation of adenosine levels in worsening of symptoms.

The hippocampal response to psychosocial stress varies with salivary uric acid level

Uric acid is a naturally occurring, endogenous compound that impacts mental health. In particular, uric acid levels are associated with emotion-related psychopathology (e.g., anxiety and depression). Therefore, understanding uric acid's impact on the brain would provide valuable new knowledge regarding neural mechanisms that mediate the relationship between uric acid and mental health. Brain regions including the prefrontal cortex, amygdala, and hippocampus underlie stress reactivity and emotion regulation. Thus, uric acid may impact emotion by modifying the function of these brain regions. The present study used functional magnetic resonance imaging (fMRI) during a psychosocial stress task to investigate the relationship between baseline uric acid levels (in saliva) and brain function. Results demonstrate that activity within the bilateral hippocampal complex varied with uric acid concentrations. Specifically, activity within the hippocampus and surrounding cortex increased as a function of uric acid level. The current findings suggest that uric acid levels modulate stress-related hippocampal activity. Given that the hippocampus has been implicated in emotion regulation during psychosocial stress, the present findings offer a potential mechanism by which uric acid impacts mental health.

Uric acid levels in subjects with bipolar disorder: A comparative meta-analysis

Previous research has hypothesised increased uric acid levels, possibly because of an amplified purinergic metabolism and a reduced adenosine activity, in subjects with bipolar disorder. This systematic review and meta-analysis aimed at estimating if individuals with bipolar disorder had uric acid levels higher than both healthy controls and subjects with major depression (trait marker hypothesis). It also tested if uric acid levels could differ in different phases of bipolar disorder (state marker hypothesis). Meta-analyses were carried out generating pooled standardized mean differences (SMDs), using random-effects models. Heterogeneity between studies was estimated using the I(2) index. Relevant sensitivity and meta-regression analyses were conducted. We searched main Electronic Databases, identifying twelve studies that met our inclusion criteria. Meta-analyses showed increased uric acid levels in individuals with bipolar disorder as compared with both healthy controls (SMD = 0.65, p < 0.001, I(2) = 82.9%) and those with major depression (SMD = 0.46, p < 0.001; I(2) = 68.7%). However, meta-regression analyses confirmed this association only as compared with healthy controls. Finally, though uric acid levels were higher in manic/mixed phases as compared with depressive ones (SMD = 0.34; p = 0.04, I(2) = 58.8%), a sensitivity analysis did not confirm the association. In sum, our meta-analysis shows that subjects with bipolar disorder have uric acid levels higher than healthy controls. The potential role of factors that might clarify the nature of this association deserves additional research.

The role of macrophage polarization on bipolar disorder: Identifying new therapeutic targets

OBJECTIVE

Bipolar disorder is a chronic, severe and disabling disease; however, its pathophysiology remains poorly understood. Recent evidence has suggested that inflammation and immune dysregulation play a significant role in the pathophysiology of bipolar disorder. This review is aimed to highlight the importance of systemic inflammation in modulating the inflammatory response of microglia and hence its potential involvement with bipolar disorder. We also discuss novel therapeutic strategies that emerge from this new research.

METHOD

This article presents a theoretical synthesis of the effects of systemic inflammation on the immune response of the central nervous system in bipolar disorder. The complex relationship between stress, pro-inflammatory cytokines and microglial dysfunction is summarized, emphasizing the role of the kynurenine pathway in this process and, consequently, their effects on neuronal plasticity.

RESULTS

Bipolar patients demonstrate increased serum levels of pro-inflammatory cytokines (interleukin-1β, interleukin-6 and tumor necrosis factor-α) and lower hypothalamic-pituitary-adrenal axis sensitivity. This imbalance in the immune system promotes a change in blood-brain barrier permeability, leading to an inflammatory signal spread in the central nervous system from the periphery, through macrophages activation (M1 polarization). Chronic microglial activation can result in neuronal apoptosis, neurogenesis inhibition, hippocampal volume reduction, lower neurotransmitters synthesis and cytotoxicity, by increasing glutamate production and kynurenine metabolism.

CONCLUSIONS

This review provides an overview of the mechanisms involved in the immune system imbalance and its potential involvement in the pathophysiology of bipolar disorder. Consequently, new strategies that normalize the immune-inflammatory pathways may provide a valuable therapeutic target for the treatment of these disorders.

Uric acid excretion predicts increased aggression in urban adolescents

Elevated levels of uric acid have been linked with impulsive and disinhibited behavior in clinical and community populations of adults, but no studies have examined uric acid in relation to adolescent aggression. This study examined the prospective role of uric acid in aggressive behavior among urban, low income adolescents, and whether this relationship varies by gender. A total of 84 adolescents (M age 13.36years; 50% male; 95% African American) self-reported on their physical aggression at baseline and 1.5years later. At baseline, the youth also completed a 12-h (overnight) urine collection at home which was used to measure uric acid excretion. After adjusting for baseline aggression and age, greater uric acid excretion predicted more frequent aggressive behavior at follow up, with no significant gender differences. The results suggest that lowering uric acid levels may help reduce youth aggression.

High Risk of Depressive Disorders in Patients With Gout: A Nationwide Population-Based Cohort Study

Metabolic abnormalities are common in patients with depressive disorders. However, the relationship between gout and depression is unclear. We explored the causal relationship among gout, antigout medication, and the associated risk of incidental depressive disorders.In this nationwide cohort study, we sampled data from the National Health Insurance Research Database to recruit 34,050 patients with gout as the gout cohort and 68,100 controls (without gout) as the nongout cohort. Our primary endpoint was the diagnosis of depressive disorders during follow-up. The overall study population was followed up until depression diagnosis, withdrawal from the NHI program, or the end of the study. The differences in demographic and clinical characteristics between both cohorts were determined using the Chi-square test for categorical variables and the t-test for continuous variables. Cox proportional hazard regression models were used to examine the effect of gout on the risk of depression, represented using the hazard ratio with the 95% confidence interval.Patients with gout exhibited a higher risk of depressive disorders than controls did. The risk of depressive disorders increased with age and was higher in female patients and those with hypertension, stroke, and coronary artery disease. Nonsteroidal antiinflammatory drug and prednisolone use was associated with a reduced risk of depression. Patients with gout who had received antigout medication exhibited a reduced risk of depressive disorders compared with nongout patients.Our findings support that gout increases the risk of depressive disorders, and that antigout medication use reduces the risk.

Factors influencing insulin resistance in relation to atherogenicity in mood disorders, the metabolic syndrome and tobacco use disorder

OBJECTIVE

This study examines the effects of malondialdehyde (MDA) and uric acid on insulin resistance and atherogenicity in subjects with and without mood disorders, the metabolic syndrome (MetS) and tobacco use disorder (TUD).

METHODS

We included 314 subjects with depression and bipolar depression, with and without the MetS and TUD and computed insulin resistance using the updated homeostasis model assessment (HOMA2IR) and atherogenicity using the atherogenic index of plasma (AIP), that is log10 (triglycerides/high density lipoprotein (HDL) cholesterol.

RESULTS

HOMA2IR is correlated with body mass index (BMI) and uric acid levels, but not with mood disorders and TUD, while the AIP is positively associated with BMI, mood disorders, TUD, uric acid, MDA and male sex. Uric acid is positively associated with insulin and triglycerides and negatively with HDL cholesterol. MDA is positively associated with triglyceride levels. Comorbid mood disorders and TUD further increase AIP but not insulin resistance. Glucose is positively associated with increasing age, male gender and BMI.

DISCUSSION

The results show that mood disorders, TUD and BMI together with elevated levels of uric acid and MDA independently contribute to increased atherogenic potential, while BMI and uric acid are risk factors for insulin resistance. The findings show that mood disorders and TUD are closely related to an increased atherogenic potential but not to insulin resistance or the MetS. Increased uric acid is a highly significant risk factor for insulin resistance and increased atherogenic potential. MDA, a marker of lipid peroxidation, further contributes to different aspects of the atherogenic potential. Mood disorders and TUD increase triglyceride levels, lower HDL cholesterol and are strongly associated with the atherogenic, but not insulin resistance, component of the MetS.

Purinergic system dysfunction in mood disorders: a key target for developing improved therapeutics

Uric acid and purines (such as adenosine) regulate mood, sleep, activity, appetite, cognition, memory, convulsive threshold, social interaction, drive, and impulsivity. A link between purinergic dysfunction and mood disorders was first proposed a century ago. Interestingly, a recent nationwide population-based study showed elevated risk of gout in subjects with bipolar disorder (BD), and a recent meta-analysis and systematic review of placebo-controlled trials of adjuvant purinergic modulators confirmed their benefits in bipolar mania. Uric acid may modulate energy and activity levels, with higher levels associated with higher energy and BD spectrum. Several recent genetic studies suggest that the purinergic system - particularly the modulation of P1 and P2 receptor subtypes - plays a role in mood disorders, lending credence to this model. Nucleotide concentrations can be measured using brain spectroscopy, and ligands for in vivo positron emission tomography (PET) imaging of adenosine (P1) receptors have been developed, thus allowing potential target engagement studies. This review discusses the key role of the purinergic system in the pathophysiology of mood disorders. Focusing on this promising therapeutic target may lead to the development of therapies with antidepressant, mood stabilization, and cognitive effects.

Increased uric acid levels in bipolar disorder subjects during different phases of illness

BACKGROUND

Recent evidence indicates the possible involvement of adenosine and the purinergic system in the pathophysiology of bipolar disorder (BD). The aim of this study is to compare serum uric acid (UA) levels in a large group of BD patients (in mania, depression and euthymia) vs. a control group of patients with different psychiatric disorders.

METHODS

150 BD (SCID-I; DSM-IV) patients were compared to 150 age- and gender-matched subjects with MDD, OCD, or Schizophrenia. Mean serum UA values were compared with the ANOVA, with Bonferroni's post-hoc tests.

RESULTS

Mean serum UA levels (5.06 ± 1.45 vs. 4.17 ± 1.05 mg/dL) and rates of hyperuricaemia (30.7% vs. 6.7%) were significantly higher in the bipolar than in the control group. No differences were detected between bipolars in different phases of illness, with all three groups (manic, depressive and euthymic bipolars) showing significantly higher UA levels as compared to controls. No correlations were found between UA levels and YMRS or HAM-D scores. Mean UA levels were also higher in bipolars never exposed to mood stabilizers vs. controls (5.08 ± 1.43 vs. 4.17 ± 1.05 mg/dL), with no differences compared to other bipolars.

LIMITATIONS

Our study suffers from the lack of a healthy comparison group; moreover, longitudinal data are missing.

CONCLUSIONS

Our study provides further evidence of a purinergic dysfunction associated with BD, in all phases of the illness. It is possible that increased UA levels are a trait marker of higher vulnerability to bipolar disorder, and are even more increased during mania (mostly in the first manic episode of drug-naïve patients).