Serological observations in patients suffering from acute manic episodes

Applications of blood-based protein biomarker strategies in the study of psychiatric disorders

Major psychiatric disorders such as schizophrenia, major depressive and bipolar disorders are severe, chronic and debilitating, and are associated with high disease burden and healthcare costs. Currently, diagnoses of these disorders rely on interview-based assessments of subjective self-reported symptoms. Early diagnosis is difficult, misdiagnosis is a frequent occurrence and there are no objective tests that aid in the prediction of individual responses to treatment. Consequently, validated biomarkers are urgently needed to help address these unmet clinical needs. Historically, psychiatric disorders are viewed as brain disorders and consequently only a few researchers have as yet evaluated systemic changes in psychiatric patients. However, promising research has begun to challenge this concept and there is an increasing awareness that disease-related changes can be traced in the peripheral system which may even be involved in the precipitation of disease onset and course. Converging evidence from molecular profiling analysis of blood serum/plasma have revealed robust molecular changes in psychiatric patients, suggesting that these disorders may be detectable in other systems of the body such as the circulating blood. In this review, we discuss the current clinical needs in psychiatry, highlight the importance of biomarkers in the field, and review a representative selection of biomarker studies to highlight opportunities for the implementation of personalized medicine approaches in the field of psychiatry. It is anticipated that the implementation of validated biomarker tests will not only improve the diagnosis and more effective treatment of psychiatric patients, but also improve prognosis and disease outcome.

Inflamed moods: a review of the interactions between inflammation and mood disorders

Mood disorders have been recognized by the World Health Organization (WHO) as the leading cause of disability worldwide. Notwithstanding the established efficacy of conventional mood agents, many treated individuals continue to remain treatment refractory and/or exhibit clinically significant residual symptoms, cognitive dysfunction, and psychosocial impairment. Therefore, a priority research and clinical agenda is to identify pathophysiological mechanisms subserving mood disorders to improve therapeutic efficacy. During the past decade, inflammation has been revisited as an important etiologic factor of mood disorders. Therefore, the purpose of this synthetic review is threefold: 1) to review the evidence for an association between inflammation and mood disorders, 2) to discuss potential pathophysiologic mechanisms that may explain this association and 3) to present novel therapeutic options currently being investigated that target the inflammatory-mood pathway. Accumulating evidence implicates inflammation as a critical mediator in the pathophysiology of mood disorders. Indeed, elevated levels of pro-inflammatory cytokines have been repeatedly demonstrated in both major depressive disorder (MDD) and bipolar disorder (BD) patients. Further, the induction of a pro-inflammatory state in healthy or medically ill subjects induces 'sickness behavior' resembling depressive symptomatology. Potential mechanisms involved include, but are not limited to, direct effects of pro-inflammatory cytokines on monoamine levels, dysregulation of the hypothalamic-pituitary-adrenal (HPA) axis, pathologic microglial cell activation, impaired neuroplasticity and structural and functional brain changes. Anti-inflammatory agents, such as acetyl-salicylic acid (ASA), celecoxib, anti-TNF-α agents, minocycline, curcumin and omega-3 fatty acids, are being investigated for use in mood disorders. Current evidence shows improved outcomes in mood disorder patients when anti-inflammatory agents are used as an adjunct to conventional therapy; however, further research is needed to establish the therapeutic benefit and appropriate dosage.

Stage managing bipolar disorder

OBJECTIVES

Clinical staging is widespread in medicine - it informs prognosis, clinical course, and treatment, and assists individualized care. Staging places an individual on a probabilistic continuum of increasing potential disease severity, ranging from clinically at-risk or latency stage through first threshold episode of illness or recurrence, and, finally, to late or end-stage disease. The aim of the present paper was to examine and update the evidence regarding staging in bipolar disorder, and how this might inform targeted and individualized intervention approaches.

METHODS

We provide a narrative review of the relevant information.

RESULTS

In bipolar disorder, the validity of staging is informed by a range of findings that accompany illness progression, including neuroimaging data suggesting incremental volume loss, cognitive changes, and a declining likelihood of response to pharmacological and psychosocial treatments. Staging informs the adoption of a number of approaches, including the active promotion of both indicated prevention for at-risk individuals and early intervention strategies for newly diagnosed individuals, and the tailored implementation of treatments according to the stage of illness.

CONCLUSIONS

The nature of bipolar disorder implies the presence of an active process of neuroprogression that is considered to be at least partly mediated by inflammation, oxidative stress, apoptosis, and changes in neurogenesis. It further supports the concept of neuroprotection, in that a diversity of agents have putative effects against these molecular targets. Clinically, staging suggests that the at-risk state or first episode is a period that requires particularly active and broad-based treatment, consistent with the hope that the temporal trajectory of the illness can be altered. Prompt treatment may be potentially neuroprotective and attenuate the neurostructural and neurocognitive changes that emerge with chronicity. Staging highlights the need for interventions at a service delivery level and implementing treatments at the earliest stage of illness possible.

Stress, schizophrenia and bipolar disorder

The role of stress in precipitating psychotic episodes in schizophrenia and bipolar disorder has long been acknowledged. However, the neurobiological mechanism/s of this association have remained elusive. Current neurodevelopmental models of psychosis implicate early dysfunction in biological systems regulating hypothalamic-pituitary-adrenal axis and immune function, with long-term effects on the development of the brain networks responsible for higher order cognitive processes and stress reactivity in later life. There is also increasing evidence of childhood trauma in psychosis, and its impact on the development of brain systems regulating stress. These findings are emerging in the context of a new era of epigenetic methods facilitating the study of environmental effects on gene expression. The evidence is thus converging: exposure to stress at critical periods in life may be an important factor in the development of the brain dysfunction that represents psychosis vulnerability, rather than merely interacting with an independent 'biological vulnerability' to manifest in psychosis.

Novel therapeutic targets in depression and anxiety: antioxidants as a candidate treatment

There is growing evidence that the imbalance between oxidative stress and the antioxidant defense system may be associated with the development neuropsychiatric disorders, such as depression and anxiety. Major depression and anxiety are presently correlated with a lowered total antioxidant state and by an activated oxidative stress (OS) pathway. The classical antidepressants may produce therapeutic effects other than regulation of monoamines by increasing the antioxidant levels and normalizing the damage caused by OS processes. This chapter provides an overview of recent work on oxidative stress markers in the animal models of depression and anxiety, as well as patients with the aforementioned mood disorders. It is well documented that antioxidants can remove the reactive oxygen species (ROS) and reactive nitrogen species (RNS) through scavenging radicals and suppressing the OS pathway, which further protect against neuronal damage caused oxidative or nitrosative stress sources in the brain, hopefully resulting in remission of depression or anxiety symptoms. The functional understanding of the relationship between oxidative stress and depression and anxiety may pave the way for discovery of novel targets for treatment of neuropsychiatric disorders.

Multiplex immunoassay analysis of plasma shows prominent upregulation of growth factor activity pathways linked to GSK3β signaling in bipolar patients

BACKGROUND

Our understanding of bipolar disorder (BD) aetiology has advanced in recent years but our ability to translate this to improve patient care in the clinic is still limited.

METHODS

In this study, we have measured the concentrations of 190 different molecules using sensitive multiplex immunoassays in plasma of 17 BD patients compared to 46 matched control subjects.

RESULTS

The analyses led to the identification of 26 dysregulated proteins in BD patients compared to controls. These molecules were comprised mostly of growth factors, hormones, lipid transport and inflammatory proteins. Decreased apolipoprotein A1 has previously been associated with BD patients and this was confirmed in our study.

LIMITATIONS

The present pilot study was limited by its small sample size, use of multiple drug treatments and the lack of dietary restrictions at the time of sampling.

CONCLUSIONS

Future studies may increase our understanding of BD which will help to pave the way for much-needed patient stratification for better treatment outcomes.

Role of immunological factors in the pathophysiology and diagnosis of bipolar disorder: comparison with schizophrenia

Several lines of evidence point to the key role of neurobiological mechanisms and shared genetic background in schizophrenia and bipolar disorder. For both disorders, neurodevelopmental and neurodegenerative processes have been postulated to be relevant for the pathogenesis as well as dysregulation of immuno-inflammatory pathways. Inflammation is a complex biological response to harmful stimuli and it is mediated by cytokines cascades, cellular immune responses, oxidative factors and hormone regulation. Cytokines, in particular, are supposed to play a critical role in infectious and inflammatory processes, mediating the cross-talk between the brain and the immune system; they also possibly contribute to the development of the central nervous system. From this perspective, even though mixed results have been reported, it seems that both schizophrenia and bipolar disorder are associated with an imbalance in inflammatory cytokines; in fact, some of these could represent biological markers of illness and could be possible targets for pharmacological treatments. In light of these considerations, the purpose of the present paper was to provide a comprehensive and critical review of the existing literature about immunological abnormalities in bipolar disorder with particular attention to the similarities and differences with schizophrenia.

Immune dysregulation and autoimmunity in bipolar disorder: Synthesis of the evidence and its clinical application

OBJECTIVE

Increasing evidence suggests that inflammation and immune dysregulation play an important role in the pathogenesis of bipolar disorder. Because the brain can be affected by various autoimmune processes, it is possible that some psychiatric disorders may have an autoimmune basis.

METHOD

This article reviews the literature on peripheral and central immune dysregulation and autoimmunity in bipolar disorder. The mechanisms of the innate and adaptive immune systems in the pathophysiology of bipolar disorder are explored. The clinical features and pathogenesis of neuropsychiatric systemic lupus erythematosus, anti-NMDA encephalitis, and Hashimoto's encephalopathy are summarized.

RESULTS

Neuroinflammation and peripheral immune dysregulation may play a role in the pathophysiology of bipolar disorder. This involves a complex interaction between immune cells of the central nervous system and periphery resulting in cellular damage through mechanisms involving excitotoxicity, oxidative stress, and mitochondrial dysfunction. Neuropsychiatric systemic lupus erythematosus, anti-NMDA encephalitis, and Hashimoto's encephalopathy are important differentials for a psychiatrist to consider when suspecting autoimmune encephalopathy.

CONCLUSIONS

The link between immune dysregulation, autoimmunity, and bipolar disorder may be closer than previously thought. Psychiatrists should be vigilant for autoimmunity in presentations of bipolar disorder due to its high morbidity and therapeutic implications. Advances in neuroimaging and biomarker identification related to immune dysregulation and neuroinflammation will contribute to our knowledge of the pathophysiology of bipolar disorder.

The association between immune activation and manic symptoms in patients with a depressive disorder

Although recent studies have shown that immunological processes play an important role in the pathophysiology of mood disorders, immune activation may only be present in specific subgroups of patients. Our study aimed to examine whether immune activation was associated with (a) the presence of manic symptoms and (b) the onset of manic symptoms during 2 years of follow-up in depressed patients. Patients with a depressive disorder at baseline (N=957) and healthy controls (N=430) were selected from the Netherlands Study of Depression and Anxiety. Assessments included lifetime manic symptoms at baseline and two-year follow up, as well as C-reactive protein (CRP), interleukin-6 (IL-6) and tumor necrosis factor alpha (TNF-α) at baseline. Within depressed patients, immune activation was not related to the presence or absence of lifetime manic symptoms at baseline. However, CRP levels were strongly elevated in depressed men who developed manic symptoms compared with those who did not develop manic symptoms over 2 years (P<0.001, Cohen's d=0.89). IL-6 and TNF-α were also higher in depressed men with an onset of manic symptoms, but this association was not significant. However, we found that the onset of manic symptoms was particularly high in men with multiple elevated levels of inflammatory markers. Depressed men who developed manic symptoms during follow-up had increased immunological activity (especially CRP) compared with depressed men who did not develop manic symptoms. Further research should explore whether a treatment approach focusing on inflammatory processes may be more effective in this specific subgroup of depressed patients.

Cytokines in bipolar disorder vs. healthy control subjects: a systematic review and meta-analysis

BACKGROUND

Bipolar disorder may be associated with peripheral immune system dysfunction; however, results in individual studies are conflicting. Our aim was to systematically review evidence of peripheral cytokine alterations in bipolar disorder integrating findings from various affective states.

METHODS

We conducted a meta-analysis of studies comparing peripheral cytokine concentrations in patients with bipolar disorder with healthy control subjects. Results were reported according to the PRISMA statement.

RESULTS

Eighteen studies with a total of 761 bipolar disorder patients and 919 healthy controls were included. Overall, concentrations of soluble Interleukin (IL)-2 receptor (sIL-2R), tumor necrosis factor-α (TNF-α), soluble tumor necrosis factor receptor type 1 (sTNFR1) (p < 0.001 each), sIL-6R (p = 0.01) and IL-4 (p = 0.04) were significantly higher in bipolar patients compared with healthy controls. There were no significant differences between bipolar disorder patients and healthy control subjects for IL-1, IL-2, IL-5, IL-6, IL-8, IL-10, IL-12, IL-1β, IL-1 receptor antagonist (IL-1RA), interferon-γ (IFN-γ), transforming growth factor-β1 (TGF-β1) and sTNFR2.

CONCLUSIONS

Employing a global approach, incorporating evidence across affective states, this meta-analysis found some support for peripheral inflammatory alterations in bipolar disorder. Results were limited by heterogeneity between studies, insufficient standardization and lacking control for confounders in individual studies. Further research exploring the role of the peripheral inflammatory system in relation to neuroinflammation is warranted.

Immunity, inflammation, and bipolar disorder: diagnostic and therapeutic implications

Bipolar disorder is now known to be associated not only with highly prevalent co-occurring psychiatric and substance use disorders but also with medical comorbidities, such as cardiovascular diseases, diabetes mellitus, obesity and thyroid dysfunction. Inflammatory disturbances repeatedly observed in bipolar disorder, can explain some of the comorbidity between bipolar disorder and medical disorder. This revised perspective of bipolar disorders should promote the development of therapeutic tools. Immuno-inflammatory dysfunction may well represent a significant component of the underlying pathophysiology of the disorder. We therefore propose to review the immuno-inflammatory hypothesis in bipolar disorder considering the co-occurence with autoimmune diseases, immunological and inflammatory markers, as well as immuno-genetic markers which could lead to personalized treatments.

Elevated immune-inflammatory signaling in mood disorders: a new therapeutic target?

Converging translational evidence has implicated elevated immune-inflammatory signaling activity in the pathoetiology of mood disorders, including major depressive disorder and bipolar disorder. This is supported in part by cross-sectional evidence for increased levels of proinflammatory eicosanoids, cytokines and acute-phase proteins during mood episodes, and prospective longitudinal evidence for the emergence of mood symptoms in response to chronic immune-inflammatory activation. In addition, mood-stabilizer and atypical antipsychotic medications downregulate initial components of the immune-inflammatory signaling pathway, and adjunctive treatment with anti-inflammatory agents augment the therapeutic efficacy of antidepressant, mood stabilizer and atypical antipsychotic medications. Potential pathogenic mechanisms linked with elevated immune-inflammatory signaling include perturbations in central serotonin neurotransmission and progressive white matter pathology. Both heritable genetic factors and environmental factors including dietary fatty-acid composition may act in concert to sustain elevated immune-inflammatory signaling. Collectively, these data suggest that elevated immune-inflammatory signaling is a mechanism that is relevant to the pathoetiology of mood disorders, and may therefore represent a new therapeutic target for the development of more effective treatments.

Selected cytokine profiles during remission in bipolar patients

OBJECTIVES

The aim of the study was to examine the cytokine status in bipolar patients during immediate remission after acute episodes of mania or depression and in patients with sustained (≥6 months) remission, compared with healthy controls.

METHODS

The study was performed on 121 bipolar patients, of whom 35 were in immediate remission after mania, 41 were in immediate remission after depression, and 45 were in >6-month remission on lithium monotherapy or lithium combined with other drugs. The control group consisted of 78 healthy individuals without any history of psychiatric or immunological illnesses. Serum concentrations of IL-1β, IL-2, IL-6, IL-10, TNF-α and IFN-γ were determined using the Human Th1/Th2 Cytometric Bead Array method.

RESULTS

The concentration of IL-10 was higher in patients in remission after mania and the concentration of IFN-γ was higher in those in remission after depression than in healthy controls. On the other hand, cytokine concentrations in patients with sustained remission were not different from those of healthy subjects.

CONCLUSIONS

The results obtained in this study show that sustained remission in bipolar patients achieved mostly by lithium maintenance brings the cytokine status to a level similar to healthy control subjects.

Cytokines in bipolar disorder: a systematic review and meta-analysis

BACKGROUND

Current research and hypothesis regarding the pathophysiology of bipolar disorder suggests the involvement of immune system dysfunction that is possibly related to disease activity. Our objective was to systematically review evidence of cytokine alterations in bipolar disorder according to affective state.

METHODS

We conducted a systemtic review of studies measuring endogenous cytokine concentrations in patients with bipolar disorder and a meta-analysis, reporting results according to the PRISMA statement.

RESULTS

Thirteen studies were included, comprising 556 bipolar disorder patients and 767 healthy controls, evaluating 15 different cytokines-, cytokine receptors- or cytokine antagonists. The levels of tumor necrosis factor-α (TNF-α), the soluble tumor necrosis factor receptor type 1 (sTNF-R1) and the soluble inlerleukin-2 receptor (sIL-2R) were elevated in manic patients compared with healthy control subjects (p<0.01 for each). Levels of sTNF-R1 and TNF-α were elevated in manic patients compared to euthymic patients (p=0.01 and p=0.04, respectively). sTNF-R1 levels were elevated in euthymic patients compared with healthy control subjects (p<0.01). There were no significant findings for other comparisons, including intra-individual alterations of cytokine levels.

LIMITATIONS

Stratification according to mood state resulted in small study numbers for some cytokines. Findings were limited by heterogeneity, small sample sizes and a lack of control for confounding factors in individual studies.

CONCLUSIONS

This meta-analysis found some support for immune dysregulation in bipolar disorder. Future research is warranted to elucidate the role of endogenous cytokine alterations in bipolar disorder. Clinical studies examining longitudinal changes within individuals are recommended.

N-acetylcysteine for major depressive episodes in bipolar disorder

OBJECTIVE

In this report, we aimed to evaluate the effect of add-on N-acetylcysteine (NAC) on depressive symptoms and functional outcomes in bipolar disorder. To that end, we conducted a secondary analysis of all patients meeting full criteria for a depressive episode in a placebo controlled trial of adjunctive NAC for bipolar disorder.

METHOD

Twenty-four week randomised clinical trial comparing adjunctive NAC and placebo in individuals with bipolar disorder experiencing major depressive episodes. Symptomatic and functional outcome data were collected over the study period.

RESULTS

Seventeen participants were available for this report. Very large effect sizes in favor of NAC were found for depressive symptoms and functional outcomes at endpoint. Eight of the ten participants on NAC had a treatment response at endpoint; the same was true for only one of the seven participants allocated to placebo.

DISCUSSION

These results indicate that adjunctive NAC may be useful for major depressive episodes in bipolar disorder. Further studies designed to confirm this hypothesis are necessary.

Novel therapeutic targets in depression: minocycline as a candidate treatment

Mood disorders are marked by high rates of non-recovery, recurrence, and chronicity, which are insufficiently addressed by current therapies. Several patho-etiological models have been proposed that are not mutually exclusive and include but are not limited to the monoamine, inflammatory, neurotrophic, gliotrophic, excitatory, and oxidative stress systems. A derivative of these observations is that treatment(s) which target one or more of these mechanistic steps may be capable of mitigating, or preventing, disparate psychopathological features. Minocycline is an agent with pleiotropic properties that targets multiple proteins and cellular processes implicated in the patho-etiology of mood disorders. Moreover, preclinical and preliminary clinical evidence suggests that minocycline possesses antidepressant properties. Herein, we provide the rationale for conducting a randomized, controlled trial to test the antidepressant properties of minocycline.

Depression and sickness behavior are Janus-faced responses to shared inflammatory pathways

It is of considerable translational importance whether depression is a form or a consequence of sickness behavior. Sickness behavior is a behavioral complex induced by infections and immune trauma and mediated by pro-inflammatory cytokines. It is an adaptive response that enhances recovery by conserving energy to combat acute inflammation. There are considerable phenomenological similarities between sickness behavior and depression, for example, behavioral inhibition, anorexia and weight loss, and melancholic (anhedonia), physio-somatic (fatigue, hyperalgesia, malaise), anxiety and neurocognitive symptoms. In clinical depression, however, a transition occurs to sensitization of immuno-inflammatory pathways, progressive damage by oxidative and nitrosative stress to lipids, proteins, and DNA, and autoimmune responses directed against self-epitopes. The latter mechanisms are the substrate of a neuroprogressive process, whereby multiple depressive episodes cause neural tissue damage and consequent functional and cognitive sequelae. Thus, shared immuno-inflammatory pathways underpin the physiology of sickness behavior and the pathophysiology of clinical depression explaining their partially overlapping phenomenology. Inflammation may provoke a Janus-faced response with a good, acute side, generating protective inflammation through sickness behavior and a bad, chronic side, for example, clinical depression, a lifelong disorder with positive feedback loops between (neuro)inflammation and (neuro)degenerative processes following less well defined triggers.

Vitamin and mineral intakes in adults with mood disorders: comparisons to nutrition standards and associations with sociodemographic and clinical variables

OBJECTIVE

The purpose of this study was to investigate the nutrient intakes of people with mood disorders.

METHOD

A cross-sectional survey using 3-day food records was carried out in 97 adults with bipolar or major depressive disorder to compare nutrient intakes with Dietary Reference Intakes and British Columbia Nutrition Survey (BCNS) data. Blood levels of selected nutrients were compared to reference ranges. Bivariate and multivariate analyses examined the effects of sociodemographic and clinical variables on nutrient intakes.

RESULTS

The average age of respondents was 46 (±13) years; most were women (n = 69) who had less than a university degree (n = 60) and whose incomes were in the government-defined lower range (n = 39). Compared with the BCNS, a larger proportion of the sample was below the estimated average requirement for thiamin (26% vs 8%), riboflavin (21% vs 4%), folate (64% vs 27%), phosphorous (12% vs 1%), and zinc (39% vs 15%; all P < 0.0001), as well as vitamin B(6) (25% vs 16%) and vitamin B(12) (27% vs 8%; both P < 0.05). Combined intakes of food and supplements helped reduce the prevalence of inadequacy; however, with supplementation, the proportion of participants exceeding the tolerable upper intake levels for niacin, vitamin B(6), folate, vitamin C, calcium, magnesium, iron, and zinc ranged from 1%-8%. Income, relationship status, age, gender, and caloric intake were associated with intakes of many nutrients. Types of medications were associated with nutrient intakes, as lower intakes of thiamin and phosphorous (P < 0.05) were found with antidepressant use, higher calcium and iron intakes (P < 0.05) were associated with antianxiety medication use, and magnesium intakes were increased with mood stabilizers (regression coefficient = 52.61, P < 0.05, 95% confidence interval = 0.74 to 104.48).

CONCLUSIONS

Adults with mood disorders are at risk for many nutrient inadequacies, as well as occasional excesses; social, demographic, and clinical factors may affect their nutrient intakes.

Minocycline: therapeutic potential in psychiatry

Pharmacological interventions to treat psychiatric illness have previously focused on modifying dysfunctional neurotransmitter systems to improve symptoms. However, imperfect understanding of the aetiology of these heterogeneous syndromes has been associated with poor treatment outcomes for many individuals. Growing evidence suggests that oxidative stress, inflammation, changes in glutamatergic pathways and neurotrophins play important roles in many psychiatric illnesses including mood disorders, schizophrenia and addiction. These novel insights into pathophysiology allow new treatment targets to be explored. Minocycline is an antibiotic that can modulate glutamate-induced excitotoxicity, and has antioxidant, anti-inflammatory and neuroprotective effects. Given that these mechanisms overlap with the newly understood pathophysiological pathways, minocycline has potential as an adjunctive treatment in psychiatry. To date there have been promising clinical indications that minocycline may be a useful treatment in psychiatry, albeit from small trials most of which were not placebo controlled. Case reports of individuals with schizophrenia, psychotic symptoms and bipolar depression have shown serendipitous benefits of minocycline treatment on psychiatric symptoms. Minocycline has been trialled in open-label or small randomized controlled trials in psychiatry. Results vary, with findings supporting use in schizophrenia, but showing less benefit for nicotine dependence and obsessive-compulsive disorder. Given the limited data from rigorous clinical trials, further research is required. However, taken together, the current evidence suggests minocycline may be a promising novel therapy in psychiatry.

Markers of gluten sensitivity in acute mania: a longitudinal study

Increased levels of antibodies to gliadin, which is derived from the wheat protein gluten, have been reported in schizophrenia and bipolar disorder in cross-sectional studies. We examined longitudinally the levels of antibody reactivity to gliadin in acute mania. The sample included 60 individuals assessed during a hospital stay for acute mania, 39 at a 6-month follow-up, and a sample of 143 non-psychiatric controls. Antibodies to gliadin were measured by enzyme immunoassay. The relationship of the antibodies to the clinical course of mania was analyzed by the use of regression models. Individuals with mania had significantly increased levels of IgG antibodies to gliadin, but not other markers of celiac disease, at baseline compared with controls in multivariate analyses. However, these levels were not significantly different from those of controls at the six month follow-up. Among the individuals with mania, elevated levels at follow-up were significantly associated with re-hospitalization in the 6-month follow-up period. The monitoring and control of gluten sensitivity may have significant effects on the management of individuals hospitalized with acute mania.

Multiple aberrations in shared inflammatory and oxidative & nitrosative stress (IO&NS) pathways explain the co-association of depression and cardiovascular disorder (CVD), and the increased risk for CVD and due mortality in depressed patients

There is evidence that there is a bidirectional relationship between major depression and cardiovascular disorder (CVD): depressed patients are a population at risk for increased cardiac morbidity and mortality, and depression is more frequent in patients who suffer from CVD. There is also evidence that inflammatory and oxidative and nitrosative stress (IO&NS) pathways underpin the common pathophysiology of both CVD and major depression. Activation of these pathways may increase risk for both disorders and contribute to shared risk. The shared IO&NS pathways that may contribute to CVD and depression comprise the following: increased levels of pro-inflammatory cytokines, like interleukin-1β (IL-1β), IL-2, IL-6, IL-8, IL-12, tumor necrosis factor-α, and interferon-γ; T cell activation; increased acute phase proteins, like C-reactive protein, haptoglobin, fibrinogen and α1-antitrypsin; complement factors; increased LPS load through bacterial translocation and subsequent gut-derived inflammation; induction of indoleamine 2,3-dioxygenase with increased levels of tryptophan catabolites; decreased levels of antioxidants, like coenzyme Q10, zinc, vitamin E, glutathione and glutathione peroxidase; increased O&NS characterized by oxidative damage to low density lipoprotein (LDL) and phospholipid inositol, increased malondialdehyde, and damage to DNA and mitochondria; increased nitrosative stress; and decreased ω3 polyunsaturated fatty acids (PUFAs). The complex interplay between the abovementioned IO&NS pathways in depression results in pro-atherogenic effects and should be regarded as a risk factor to future clinical CVD and due mortality. We suggest that major depression should be added as a risk factor to the Charlson "comorbidity" index. It is advised that patients with (sub)chronic or recurrent major depression should routinely be assessed by serology tests to predict if they have an increased risk to cardiovascular disorders.

Diet quality in bipolar disorder in a population-based sample of women

BACKGROUND

Recent epidemiological evidence has indicated a role for diet quality in unipolar depressive illness. This study examined the association between diet quality and bipolar disorder (BD) in an epidemiological cohort of randomly selected, population-based women aged 20-93 years.

METHODS

An a priori diet quality score was derived from food frequency questionnaire data, a factor analysis identified habitual dietary patterns and glycemic load was assessed. Mental health was assessed using the SCID-I/NP.

RESULTS

BD was identified in 23 women and there were 691 participants with no history of psychopathology. Compared to those with no psychopathology, those with BD had a higher glycemic load (p=0.06) and higher scores on a 'western' dietary factor (p=0.03) and the 'modern' dietary factor (p=0.02). For each standard deviation increase in a 'western' and 'modern' dietary pattern and glycemic load, the odds ratios for BD were increased ('western' OR=1.88, 95% CI 1.33-2.65; 'modern' OR=1.72, 95% CI 1.14-2.39; GL OR=1.56, 95% CI 1.13-2.14). Conversely, a 'traditional' dietary pattern was associated with reduced odds for BD (OR=0.53 95% CI 0.32-0.89) after adjustments for overall energy intake.

LIMITATIONS

The small sample size did not allow for multivariate analyses and the cross-sectional study design precludes any determinations regarding the direction of the relationships between diet quality and BD.

CONCLUSION

These data are largely concordant with results from dietary studies in unipolar depression. However, clinical recommendations cannot be made until the direction of the relationship between diet quality and BD is determined. Longitudinal studies are warranted.

Pathways underlying neuroprogression in bipolar disorder: focus on inflammation, oxidative stress and neurotrophic factors

There is now strong evidence of progressive neuropathological processes in bipolar disorder (BD). On this basis, the current understanding of the neurobiology of BD has shifted from an initial focus on monoamines, subsequently including evidence of changes in intracellular second messenger systems and more recently to, incorporating changes in inflammatory cytokines, corticosteroids, neurotrophins, mitochondrial energy generation, oxidative stress and neurogenesis into a more comprehensive model capable of explaining some of the clinical features of BD. These features include progressive shortening of the inter-episode interval with each recurrence, occurring in consort with reduced probability of treatment response as the illness progresses. To this end, emerging data shows that these biomarkers may differ between early and late stages of BD in parallel with stage-related structural and neurocognitive alterations. This understanding facilitates identification of rational therapeutic targets, and the development of novel treatment classes. Additionally, these pathways provide a cogent explanation for the efficacy of seemingly diverse therapies used in BD, that appear to share common effects on oxidative, inflammatory and neurotrophic pathways.

Melatonin as a potential therapeutic agent in psychiatric illness

The aim of this review was to summarize the potential use of melatonin in the treatment of mental disorders, specifically bipolar disorders, depression, and schizophrenia. To date, melatonin has been most commonly used in psychiatry because of its hypnotic, rhythm resynchronizing, and antioxidant actions. Here, we examine other properties of the melatonin including its anti-inflammatory, antinociceptive, anxiolytic, and drug detoxification actions as well as its protective effects against neural loss. The brain is an intricate sensory and motor organ which receives information from both the external and internal environments. It transduces information into complex chemical and electrical signals which are transmitted throughout the central nervous system (CNS) and the organism. The pathogenesis of mental disorders remains ambiguous and neuroinflammation has been proposed as a causative agent. We consider the potential contributions of melatonin as therapeutic agent in CNS and during neuroinflammation in mental disorders.

The inflammatory & neurodegenerative (I&ND) hypothesis of depression: leads for future research and new drug developments in depression

Despite extensive research, the current theories on serotonergic dysfunctions and cortisol hypersecretion do not provide sufficient explanations for the nature of depression. Rational treatments aimed at causal factors of depression are not available yet. With the currently available antidepressant drugs, which mainly target serotonin, less than two thirds of depressed patients achieve remission. There is now evidence that inflammatory and neurodegenerative (I&ND) processes play an important role in depression and that enhanced neurodegeneration in depression may-at least partly-be caused by inflammatory processes. Multiple inflammatory-cytokines, oxygen radical damage, tryptophan catabolites-and neurodegenerative biomarkers have been established in patients with depression and these findings are corroborated by animal models of depression. A number of vulnerability factors may predispose towards depression by enhancing inflammatory reactions, e.g. lower peptidase activities (dipeptidyl-peptidase IV, DPP IV), lower omega-3 polyunsaturated levels and an increased gut permeability (leaky gut). The cytokine hypothesis considers that external, e.g. psychosocial stressors, and internal stressors, e.g. organic inflammatory disorders or conditions, such as the postpartum period, may trigger depression via inflammatory processes. Most if not all antidepressants have specific anti-inflammatory effects, while restoration of decreased neurogenesis, which may be induced by inflammatory processes, may be related to the therapeutic efficacy of antidepressant treatments. Future research to disentangle the complex etiology of depression calls for a powerful paradigm shift, i.e. by means of a high throughput-high quality screening, including functional genetics and genotyping microarrays; established and novel animal and ex vivo-in vitro models for depression, such as new transgenic mouse models and endophenotype-based animal models, specific cell lines, in vivo and ex vivo electroporation, and organotypic brain slice culture models. This screening will allow to: 1) discover new I&ND biomarkers, both at the level of gene expression and the phenotype; and elucidate the underlying molecular I&ND pathways causing depression; and 2) identify new therapeutic targets in the I&ND pathways; develop new anti-I&ND drugs for these targets; select existing anti-I&ND drugs or substances that could augment the efficacy of antidepressants; and predict therapeutic response by genetic I&ND profiles.

Episode-specific differential gene expression of peripheral blood mononuclear cells in rapid cycling supports novel treatment approaches

Molecular mechanisms underlying bipolar affective disorders are unknown. Difficulties arise from genetic and phenotypic heterogeneity of patients and the lack of animal models. Thus, we focused on only one patient (n = 1) with an extreme form of rapid cycling. Ribonucleic acid (RNA) from peripheral blood mononuclear cells (PBMC) was analyzed in a three-tiered approach under widely standardized conditions. Firstly, RNA was extracted from PBMC of eight blood samples, obtained on two consecutive days within one particular episode, including two different consecutive depressive and two different consecutive manic episodes, and submitted to (1) screening by microarray hybridizations, followed by (2) detailed bioinformatic analysis, and (3) confirmation of episode-specific regulation of genes by quantitative real-time polymerase chain reaction (qRT-PCR).Secondly, results were validated in additional blood samples obtained one to two years later. Among gene transcripts elevated in depressed episodes were prostaglandin D synthetase (PTGDS) and prostaglandin D2 11-ketoreductase (AKR1C3), both involved in hibernation. We hypothesized them to account for some of the rapid cycling symptoms. A subsequent treatment approach over 5 months applying the cyclooxygenase inhibitor celecoxib (2 x 200 mg daily) resulted in reduced severity rating of both depressed and manic episodes. This case suggests that rapid cycling is a systemic disease, resembling hibernation, with prostaglandins playing a mediator role.

Investigation of serum high-sensitive C-reactive protein levels across all mood states in bipolar disorder

There has been an increasing interest in the role of the immune and inflammatory systems in mood disorders. Mood episodes are associated with changes in acute phase proteins such as high-sensitivity C-reactive protein (hsCRP). The present study investigated serum hsCRP in manic, depressed, and euthymic BD patients as compared to matched healthy controls. Serum hsCRP was assessed using an ultrasensitive assay of particle-enhanced immunoturbidimetric latex agglutination. Serum hsCRP levels were increased in manic BD patients, as compared to euthymic, depressed patients and healthy controls (P < 0.001). These findings add to the notion that changes in the inflammatory system take place during acute episodes of mania.

Evaluation of C-Reactive Protein and Total Serum Cholesterol in Adult Patients with Bipolar Disorder

The aim of the present study is to evaluate the role of CRP and Total Cholesterol (TC) in patients suffering from type I Bipolar Disorder (BD-I). Moreover, the goal is to elucidate possible CRP and TC differences in different phases of BD-I: acute mania, euthymia and bipolar depression. Medical records of 90 BD-I patients (30 patients with acute mania, 30 in euthymic state, full remission, and 30 in depressive phase) were reviewed to evaluate serum CRP and TC levels. Laboratory data of 30 healthy controls were also obtained. The scores of Young Mania Rating Scale (YMRS), Bech-Rafaelsen Manic Rating Scale (BRMRS) and Hamilton Rating Scale for Depression (HAM-D) were evaluated. CRP levels were higher in acute mania and depressive phase subgroups when compared to healthy controls. CRP was positively associated with BRMRS and YMRS scores in acute mania and with HAM-D in depressive phase subgroups. TC levels were lower in all clinical groups compared to controls. TC levels were negatively correlated to BRMRS, YMRS and HAM-D. In conclusion, the results of the present study support the notion that CRP and TC may be altered in patients with BP-I.

Elevated serum levels of C-reactive protein are associated with mania symptoms in outpatients with bipolar disorder

OBJECTIVES

We investigated the association between serum levels of C-reactive protein (CRP), a marker of inflammation, and the severity of psychopathology in outpatients with bipolar disorder. We also compared the levels of CRP in the bipolar disorder individuals with those of a non-psychiatric control group.

METHODS

We measured the level of CRP in N=122 outpatients with bipolar disorder and N=165 control individuals and evaluated the symptom severity of the bipolar disorder patients with the Young Mania Rating Scale (YMRS) and the Hamilton Depression Scale (Ham-D).

RESULTS

Within the bipolar disorder sample, CRP was significantly associated with the YMRS score (r=.306, p<.006), age of onset, gender, and race. CRP was not significantly associated with the Ham-D score or other clinical or demographic variables. In a multivariate analysis of covariance, CRP was the only independent predictor of YMRS score (F=11.7, p=.0009). The CRP levels of the n=41 individuals with YMRS >6 were significantly greater than the levels of the n=81 individuals with YMRS <or=6 (F=7.94, <.006). The CRP levels of the group with YMRS >6 were also significantly greater than the levels of the control group (p=.033) while the CRP levels of the group with YMRS <or=6 did not differ from that of controls (p>.05).

CONCLUSIONS

Our results suggest that outpatients with bipolar disorder with mania symptoms have increased levels of CRP as compared to those without mania symptoms and compared to individuals without psychiatric disorders. The long-term consequences of CRP in bipolar disorder should be the subject of future studies.

High-sensitivity C-reactive protein levels in patients with major depressive disorder and bipolar mania

The serum high-sensitivity C-reactive protein (hsCRP) levels in patients with major depressive disorder and bipolar I disorder in acute phases were investigated. During a 1-year period, a total of 67 participants including 23 patients with major depressive disorder, 13 patients with bipolar I disorder (manic episode) and 31 healthy controls were recruited in this study. The diagnoses of mental disorders in participants were made by one psychiatrist according to the Structured Clinical Interview for DSM-IV Axis I Disorders (SCID). Both patient groups with major depression and bipolar disorder had higher mean serum hsCRP levels than the healthy control group. Using analysis of covariance with age adjustment, patients with bipolar I disorders still had significantly higher hsCRP levels than healthy controls (P=0.043). However, patients with major depression did not have significantly higher hsCRP levels than healthy controls (P=0.172). These results suggest that patients with bipolar I disorder might have a more severe inflammation reaction than patients without major depression. However, larger samples and adequate statistical methods are needed to prove these results.

Linkage disequilibrium analysis in the LOC93081-KDELC1-BIVM region on 13q in bipolar disorder

Genome-wide scans in bipolar disorder and a meta analysis on published data have provided evidence for linkage to chromosome 13q, although the reported peaks from various studies have not converged in a narrow region. Recently, single nucleotide polymorphisms (SNPs) at the G72/G30 locus have been shown to be associated with bipolar disorder suggesting its potential role in increasing disease risk. The proposed linkage region on 13q extends over a wide span, and could provide a clue to the existence of other susceptibility variants. In the present study, SNPs in the LOC93081-KDELC1-BIVM, a region proximal to G72, were interrogated in two bipolar family series. KDELC1 has a predicted filamin domain and BIVM contains an immunoglobulin-like motif. The small pedigree series yielded a nominally significant global P-value due to under-transmission of a rare haplotype but this finding was not supported by results from the larger series and in the case-control study that compared 278 cases and 277 controls.