White blood cell count correlates with mood symptom severity and specific mood symptoms in bipolar disorder

Chronic Low-Grade Inflammation and Brain Structure in the Middle-Aged and Elderly Adults

Low-grade inflammation (LGI) mainly acted as the mediator of the association of obesity and inflammatory diet with numerous chronic diseases, including neuropsychiatric diseases. However, the evidence about the effect of LGI on brain structure is limited but important, especially in the context of accelerating aging. This study was then designed to close the gap, and we leveraged a total of 37,699 participants from the UK Biobank and utilized inflammation score (INFLA-score) to measure LGI. We built the longitudinal relationships of INFLA-score with brain imaging phenotypes using multiple linear regression models. We further analyzed the interactive effects of specific covariates. The results showed high level inflammation reduced the volumes of the subcortex and cortex, especially the globus pallidus (β [95% confidence interval] = -0.062 [-0.083, -0.041]), thalamus (-0.053 [-0.073, -0.033]), insula (-0.052 [-0.072, -0.032]), superior temporal gyrus (-0.049 [-0.069, -0.028]), lateral orbitofrontal cortex (-0.047 [-0.068, -0.027]), and others. Most significant effects were observed among urban residents. Furthermore, males and individuals with physical frailty were susceptive to the associations. The study provided potential insights into pathological changes during disease progression and might aid in the development of preventive and control targets in an age-friendly city to promote great health and well-being for sustainable development goals.

Better understanding of c-reactive protein and leukocytes in psychiatric inpatients with affective disorders: A biopsychosocial approach

BACKGROUND

Affective disorders (AD) have been linked to inflammatory processes, although the underlying mechanisms of this relationship are still not fully elucidated. It is hypothesized that demographic, somatic, lifestyle, and personality variables predict inflammatory parameters in AD.

AIM

To identify biopsychosocial factors contributing to inflammation in AD measured with two parameters, C-reactive protein (CRP) and leukocytes.

METHODS

This observational study investigated 186 hospital inpatients diagnosed with AD using demographic parameters, serum inflammatory markers, somatic variables, psychological questionnaires, and lifestyle parameters. Hierarchical regression analyses were used to predict inflammatory markers from demographic, somatic, lifestyle, and personality variables.

RESULTS

Analyses showed that 33.8% of the variance of CRP was explained by body mass index and other somatic medication (e.g. anti-diabetics), age and education, and age of affective disorder diagnosis. For leukocytes, 20.1% of the variance was explained by smoking, diet, metabolic syndrome (MetS), and anti-inflammatory medication (e.g. non-steroidal anti-inflammatory drugs). Other psychiatric or behavioural variables did not reach significance.

CONCLUSION

Metabolic components seem important, with mounting evidence for a metabolic affective disorder subtype. Lifestyle modifications and psychoeducation should be employed to prevent or treat MetS in AD.

Neutrophil-to-Lymphocyte, Monocyte-to-Lymphocyte, Platelet-to-Lymphocyte Ratio and Systemic Immune-Inflammatory Index in Different States of Bipolar Disorder

The neutrophil-to-lymphocyte ratio (NLR), monocyte-to-lymphocyte ratio (MLR), platelet-to-lymphocyte ratio (PLR) and systemic immune-inflammatory (SII) index, which provide a simple, rapid, inexpensive method to measure the level of inflammation, have been examined as potential inflammatory biomarkers of bipolar disorder (BD) in several studies. We conducted a case-control study recruiting 180 BD patients and 407 healthy controls. BD patients who met the inclusion criteria and were hospitalized due to BD at the psychiatry clinic of the University General Hospital of Larisa, Greece, until September 2021 were included in the study. Among them, 111 patients experienced a manic episode and 69 patients experienced a depressive episode. Data including a complete blood count were retrieved from their first admission to the hospital. Bipolar patients had a higher NLR, MLR and SII index compared to healthy controls when they were experiencing a manic episode (p < 0.001) and a depressive episode (p < 0.001). MLR was increased with large effect size only in patients expressing manic episodes. Neutrophils and NLR had the highest area under the curve with a cutoff of 4.38 and 2.15 in the ROC curve, respectively. Gender-related differences were mainly observed in the SII index, with males who were expressing manic episodes and females expressing depressive episodes having an increased index compared to healthy controls. The NLR, MLR and SII index were significantly higher in patients with BD than in healthy controls, which implies a higher grade of inflammation in BD patients.

Targeting the Adaptive Immune System in Depression: Focus on T Helper 17 Cells

There is a vital need to understand mechanisms contributing to susceptibility to depression to improve treatments for the 11% of Americans who currently suffer from this debilitating disease. The adaptive immune system, comprising T and B cells, has emerged as a potential contributor to depression, as demonstrated in the context of lymphopenic mice. Overall, patients with depression have reduced circulating T and regulatory B cells, "immunosuppressed" T cells, and alterations in the relative abundance of T cell subtypes. T helper (Th) cells have the capacity to differentiate to various lineages depending on the cytokine environment, antigen stimulation, and costimulation. Regulatory T cells are decreased, and the Th1/Th2 ratio and the Th17 cells are increased in patients with depression. Evidence for changes in each Th lineage has been reported to some extent in patients with depression. However, the evidence is strongest for the association of depression with changes in Th17 cells. Th17 cells produce the inflammatory cytokine interleukin (IL)-17A, and the discovery of Th17 cell involvement in depression evolved from the well established link that IL-6, which is required for Th17 cell differentiation, contributes to the onset, and possibly maintenance, of depression. One intriguing action of Th17 cells is their participation in the gut-brain axis to mediate stress responses. Although the mechanisms of action of Th17 cells in depression remain unclear, neutralization of IL-17A by anti-IL-17A antibodies, blocking stress-induced production, or release of gut Th17 cells represent feasible therapeutic approaches and might provide a new avenue to improve depression symptoms. SIGNIFICANCE STATEMENT: Th17 cells appear as a promising therapeutic target for depression, for which efficacious therapeutic options are limited. The use of neutralizing antibodies targeting Th17 cells has provided encouraging results in depressed patients with comorbid autoimmune diseases.

Cardiometabolic risk markers during mood-stabilizing treatment: Correlation with drug-specific effects, depressive symptoms and treatment response

BACKGROUND

Patients with bipolar disorder have higher rates of cardiometabolic comorbidities and mortality. Although guidelines emphasize the importance of cardiovascular monitoring, few studies characterized the cardiometabolic risk profile during treatment and their relation to symptomatology and treatment response.

METHODS

We analyzed data from two similar 24-weeks comparative effectiveness trials, with a combined sample of 770 participants randomized to two different lithium doses, quetiapine (300 mg/day), or standard treatment without lithium. Glucose, lipids and vital signs were measured before and after 24 weeks of treatment. We calculated several cardiovascular risk scores, assessed baseline correlations and compared the four treatment arms via multiple linear regression models.

RESULTS

Higher cholesterol and LDL levels were associated with greater depression severity, showing differential correlations to specific symptoms, particularly agitation, low energy and suicidality. Those randomized to quetiapine showed a significant worsening of cardiometabolic markers during the 24-week trial. Neither baseline nor change in lipid levels correlated with differential treatment response.

LIMITATIONS

Study duration was short from the perspective of cardiometabolic risk markers, and all treatment arms included patients taking adjunct antipsychotics. The trials compared quetiapine to lithium, but not to other medications known to affect similar risk factors.

CONCLUSIONS

Treatment with 300 mg/day quetiapine for 24 weeks, representing a short and common dose course, resulted in increased cardiometabolic risk markers, emphasizing the importance of monitoring during mood-stabilizing treatment. The symptom-specific associations are in line with previous studies in unipolar depression, suggesting a cardiometabolic-depression link that needs to be further studied in bipolar depression.

A unified model of the pathophysiology of bipolar disorder

This work provides an overview of the most consistent alterations in bipolar disorder (BD), attempting to unify them in an internally coherent working model of the pathophysiology of BD. Data on immune-inflammatory changes, structural brain abnormalities (in gray and white matter), and functional brain alterations (from neurotransmitter signaling to intrinsic brain activity) in BD were reviewed. Based on the reported data, (1) we hypothesized that the core pathological alteration in BD is a damage of the limbic network that results in alterations of neurotransmitter signaling. Although heterogeneous conditions can lead to such damage, we supposed that the main pathophysiological mechanism is traceable to an immune/inflammatory-mediated alteration of white matter involving the limbic network connections, which destabilizes the neurotransmitter signaling, such as dopamine and serotonin signaling. Then, (2) we suggested that changes in such neurotransmitter signaling (potentially triggered by heterogeneous stressors onto a structurally-damaged limbic network) lead to phasic (and often recurrent) reconfigurations of intrinsic brain activity, from abnormal subcortical-cortical coupling to changes in network activity. We suggested that the resulting dysbalance between networks, such as sensorimotor networks, salience network, and default-mode network, clinically manifest in combined alterations of psychomotricity, affectivity, and thought during the manic and depressive phases of BD. Finally, (3) we supposed that an additional contribution of gray matter alterations and related cognitive deterioration characterize a clinical-biological subgroup of BD. This model may provide a general framework for integrating the current data on BD and suggests novel specific hypotheses, prompting for a better understanding of the pathophysiology of BD.

Depression and inflammation: Correlation between changes in inflammatory markers with antidepressant response and long-term prognosis

Inflammation may correlate with a specific subgroup of depression and differential antidepressant response, but no trial has studied changes of many inflammatory markers over several time points and evaluated symptom-specific antidepressant response and long-term prognosis. We performed secondary analyses among 90 outpatients with moderate-severe depression (71% female, mean age 38 years) treated for 26 weeks with escitalopram or nortriptyline. We measured 27 pro- and anti-inflammatory markers at week 0, 8, 12, and 26 and calculated composite inflammation scores. Three depression rating scales were applied and symptom dimensions of depression calculated. Via Danish nationwide registers, 10 years follow-up were included on psychiatric hospital contacts, indicating relapse. Pearson correlation analyses were performed between baseline inflammatory markers and depressive symptom severity, mixed effects models during the 26-week trial, and Cox regression analyses for the register-based outcomes, adjusted for age, sex, BMI, and smoking. Baseline inflammatory markers correlated with differential severity on specific symptom dimensions but not with overall depression severity. A total of 17 of 27 inflammatory markers decreased significantly during treatment. We found no correlation between baseline nor change in inflammatory markers nor composite inflammation scores with differential treatment response on the MADRS, but small correlations between changes in inflammatory markers and differential response on neurovegetative symptoms. Findings were similar among 59 treatment-naïve patients. Inflammatory markers were not associated with differential risks for 10-year relapse. These findings support the importance of studying specific depressive symptoms to further explore the correlation between inflammation with differential antidepressant response in a subgroup of depression. Clinical Trial Registration number: GENDEP is registered at EudraCT2004-001723-38 (http://eudract.emea.europa.eu) and ISRCTN03693000 (www.controlled-trials.com).

Role of leukocytes, gender, and symptom domains in the influence of depression on hospitalization and mortality risk: Findings from the Moli-sani study

BACKGROUND

Major depressive disorder is a mental illness associated with chronic conditions like cardiovascular disease (CVD). Circulating inflammation has been proposed as a potential mechanism underlying this link, although the role of specific biomarkers, gender, and symptom domains is not well elucidated.

METHODS

We performed multivariable Cox regressions of first hospitalization/all-cause mortality and CVD, ischemic heart (IHD), and cerebrovascular disease (CeVD) causes vs. depression severity in an Italian population cohort (N = 13,191; age ≥ 35 years; 49.3% men; 4,856 hospitalizations and 471 deaths, median follow-up 7.28 and 8.24 years, respectively). In models adjusted for age, sex, and socioeconomic status, we estimated the proportion of association explained by C-reactive protein (CRP), platelet count, granulocyte-to-lymphocyte ratio (GLR), and white blood cell count (WBC). Gender-by-depression interaction and gender-stratified analyses were performed. Associations of polychoric factors tagging somatic and cognitive symptoms with incident clinical risks were also tested, as well as the proportion explained by a composite index of circulating inflammation (INFLA score).

RESULTS

Significant proportions of the influence of depression on clinical risks were explained by CRP (4.8% on IHD hospitalizations), GLR (11% on all-cause mortality), and WBC (24% on IHD/CeVD hospitalizations). Gender-by-depression interaction was significantly associated only with all-cause mortality (p = 0.03), with moderate depression showing a + 60% increased risk in women, but not in men. Stable associations of somatic, but not of cognitive, symptoms with increased hospitalization risk were observed (+ 16% for all causes, + 14% for CVD causes), with INFLA score explaining small but significant proportions of these associations (2.5% for all causes, 8.6% for IHD causes).

CONCLUSIONS

These findings highlight the importance of cellular components of inflammation, gender, and somatic depressive symptoms in the link between depression and clinical (especially CVD) risks, pointing to the existence of additional pathways through which depression may play a detrimental effect on the cardiovascular system.

Challenges in Treating Cancer Patients With Unstable Psychiatric Disorder

In this review, we first present a case of chronic myeloid leukemia with acute psychosis, and then we will discuss the incidence of cancer in patients with psychotic disorders, the manifestations of new-onset psychosis, and the prevalence of preexisting psychosis in cancer patients, coupled with their impact on the treatment, diagnosis, and prognosis of cancer. This was a case that presented with acute psychosis and was found to have an elevated white blood cell count upon admission to an inpatient psychiatric unit. He was diagnosed with chronic myeloid leukemia and successfully managed with imatinib/dasatinib therapy. Psychiatrically, he was stabilized on two long-acting injectable medications to help maintain adherence. We were able to eliminate his active psychotic symptoms and return him to normal functioning in affect and thinking, achieving sustained compliance with treatment. We identified multiple inconsistencies in screening for cancer of all types in these patients, masking of signs and symptoms that would typically clue physicians to the presence of cancers, underreporting of symptoms, and disparate access to healthcare resources in patients with mental disorders when compared to the general population. Treatment of cancer in these patients as compared to the general population has also been shown to be incongruent, which will be elaborated upon. Psychiatric interventions, as well as supportive measures, for treating patients who are facing challenges during active cancer treatment will be discussed.

Inflammatory and metabolic disturbances are associated with more severe trajectories of late-life depression

Late-life depression is a highly prevalent mental health condition with devastating consequences even from its earliest stages. Alterations in physiological functions, such as inflammatory and metabolic, have been described in patients with depression. However, little is known on the association between depression symptom course and metabolic and inflammation dysregulation. This study aimed to depict the course of depression symptoms while ageing, taking into consideration inter-individual heterogeneity. Moreover, it intended to study the associations between inflammatory and metabolic risk profiles and symptom trajectories. To do so, data from 13,203 adults aged 50-90 years (52.75% women; mean age at baseline = 65.07, SD = 10.00) were used. Blood sample and blood pressure measures were taken from 1536 participants (56.58% women; mean age at baseline = 61.73 years, sd = 7.64). Depression symptoms were assessed every two years across a 10-year follow-up. Trajectories were identified by means of latent class mixed modelling. Inflammation and metabolic risk profile scores were obtained from plasma and diagnostic-based indicators in the follow-up, using a robust latent-factor approach. Multigroup modelling was used to study the associations between the profiles and symptom trajectories. As a result, three heterogeneous trajectories of symptoms were identified (low-symptom, moderate-symptom and high-symptom trajectory). Participants depicting a high-symptom trajectory showed the greatest inflammation profile score and high metabolic risk. Moderate-symptom trajectory was also related to high inflammation and metabolic risk. To sum up, at-risk trajectories of symptoms were associated with high inflammation and risk of metabolic diseases. This study provides valuable evidence to advance personalised medicine and mental health precision, considering person-specific profiles and physiological concomitants.

Serum level of nerve growth factor is a potential biomarker of conversion to bipolar disorder in women with major depressive disorder

AIM

The aim of this study was to identify biomarkers associated with major depressive disorder (MDD) and conversion from MDD to bipolar disorder (BD) in an outpatient sample of women.

METHODS

This was a longitudinal study including women diagnosed with MDD and aged 18 to 60 years. The follow-up was 3 years. The diagnosis was performed using the Mini International Neuropsychiatric Interview Plus. Blood collection was just performed in the first phase. Serum interleukin-6, tumor necrosis factor-α, brain-derived neurotrophic factor, glial cell-derived neurotrophic factor, and nerve growth factor (NGF) levels were measured using a commercial immunoassay kit.

RESULTS

We included 156 women. The conversion rate from MDD to BD was 15.4% (n = 24). NGF serum levels were increased in patients who converted to BD compared to the remitted MDD group and current MDD group (P = 0.013). The Bonferroni post-hoc test for multiple comparisons revealed significant differences for higher NGF levels in patients who converted to BD compared to patients with current MDD (P = 0.037). Interleukin-6, tumor necrosis factor-α, brain-derived neurotrophic factor, and glial cell-derived neurotrophic factor serum levels did not differ among the groups.

CONCLUSION

Our results suggest that NGF might be a useful biomarker associated with early detection of conversion to BD, helping clinicians in the clinical diagnosis.

Correlation between white blood cell count and mood-stabilising treatment response in two bipolar disorder trials

BACKGROUND

Immune system markers may predict affective disorder treatment response, but whether an overall immune system marker predicts bipolar disorder treatment effect is unclear.

METHODS

Bipolar CHOICE (N = 482) and LiTMUS (N = 283) were similar comparative effectiveness trials treating patients with bipolar disorder for 24 weeks with four different treatment arms (standard-dose lithium, quetiapine, moderate-dose lithium plus optimised personalised treatment (OPT) and OPT without lithium). We performed secondary mixed effects linear regression analyses adjusted for age, gender, smoking and body mass index to investigate relationships between pre-treatment white blood cell (WBC) levels and clinical global impression scale (CGI) response.

RESULTS

Compared to participants with WBC counts of 4.5-10 × 109/l, participants with WBC &lt; 4.5 or WBC ≥ 10 showed similar improvement within each specific treatment arm and in gender-stratified analyses.

CONCLUSIONS

An overall immune system marker did not predict differential treatment response to four different treatment approaches for bipolar disorder all lasting 24 weeks.

The association between low-grade inflammation and the clinical features of bipolar disorder in Han Chinese population

Variety of evidence suggests that low-grade inflammation may be involved in the pathophysiology of bipolar disorder (BD). However, the conclusion regarding the relationship between inflammation and BD has been inconsistent. In this study, we aimed to survey the prevalence of low-grade inflammation in a large Han Chinese population with BD and assess its impact on the clinical features of BD. 430 eligible cases were drawn from patients who were admitted or had ever been admitted for BD to the inpatient service of the psychiatric department of the Third Hospital of Sun Yat-sen University. Subjects with current active physical diseases or white blood count (WBC) >19.0 × 10⁹/L (2 times the upper reference) were excluded. Serum C-reactive protein (CRP) levels and WBC were measured with fast blood sample. Low-grade inflammation was defined as CRP>3 mg/L or WBC > 9.5 × 10⁹/L(the upper reference). Clinical features of BD were collected through semi-structural interview conducted by trained interviewers with background of psychiatric education. If defined as CRP>3 mg/L, the prevalence of low-grade inflammation among BD was 10.1% (41/404), it was positively associated with BMI (p = 0.012), comorbidity of glycolipid metabolic diseases(p = 0.018). After adjusting for BMI, it was found to be positively related to recent suicide attempt (p = 0.03), initiation with (hypo)manic episode(p = 0.047), leaden paralysis (p = 0.037) and family history of mental disorders(p = 0.012), while the association between comorbidity of glycolipid metabolic diseases and low-grade inflammation disappeared (p = 0.330). If defined as WBC > 9.5 × 10⁹/L, the prevalence of low-grade inflammation was 8.1% (33/409), it was positively associated with psychotic features (p = 0.011) and adverse life events before the onset of illness(p < 0.001), but was not significantly influenced by BMI (p = 0.077). A much lower prevalence of low-grade inflammation in BD is found among Han Chinese population than among western population. Low-grade inflammation of different definition impacts differentially on the clinical features of BD.

Evaluation of serum inflammatory markers in treatment-resistant manic patients and adequate responder manic patients

Mania is accompanied with immune activation as indicated by increased pro-inflammatory cytokines, acute phase proteins; and carcinoembryonic antigen (CEA) is known to accompany signs of immune-inflammatory responses in bipolar disorder (BD) and medical disorders. In this study, it was aimed to compare high sensitivity C-reactive protein (hsCRP), CEA levels and white blood cells (WBCs) counts in the treatment-resistant BD (Group 3), the treatment-responsive BD patients (Group 2), and the healthy control group (Group 1). The sociodemographic data form, the Young Mania Rating Scale (YMRS), the Hamilton Depression Rating Scale (HDRS), and the Clinical Global Impression Severity of Illness (CGI-S) Scale were applied to the patients. In Group 3, the WBCs counts, and CEA levels were significantly higher than the other two groups. There was a positive correlation between WBCs counts and YMRS and CGI-S scores in all manic patients. There was a positive correlation between CEA levels and YMRS, HDRS and CGI-S in manic patients. This study shows that there is an activation of the immune-inflammatory response system in treatment resistant manic patients; and, WBCs counts and CEA levels are associated with severity of disease in manic patients.

Clinically relevant and simple immune system measure is related to symptom burden in bipolar disorder

OBJECTIVE

Immunological theories, particularly the sickness syndrome theory, may explain psychopathology in mood disorders. However, no clinical trials have investigated the association between overall immune system markers with a wide range of specific symptoms including potential gender differences.

METHODS

We included two similar clinical trials, the lithium treatment moderate-dose use study and clinical and health outcomes initiatives in comparative effectiveness for bipolar disorder study, enrolling 765 participants with bipolar disorder. At study entry, white blood cell (WBC) count was measured and psychopathology assessed with the Montgomery and Aasberg depression rating scale (MADRS). We performed analysis of variance and linear regression analyses to investigate the relationship between the deviation from the median WBC, and multinomial regression analysis between different WBC levels. All analyses were performed gender-specific and adjusted for age, body mass index, smoking, race, and somatic diseases.

RESULTS

The overall MADRS score increased significantly for each 1.0×109/l deviation from the median WBC among 322 men (coefficient=1.10; 95% CI=0.32-1.89; p=0.006), but not among 443 women (coefficient=0.56; 95% CI=-0.19-1.31; p=0.14). Among men, WBC deviations were associated with increased severity of sadness, inner tension, reduced sleep, reduced appetite, concentration difficulties, inability to feel, and suicidal thoughts. Among women, WBC deviations were associated with increased severity of reduced appetite, concentration difficulties, lassitude, inability to feel, and pessimistic thoughts. Both higher and lower WBC levels were associated with increased severity of several specific symptoms.

CONCLUSION

Immune system alterations were associated with increased severity of specific mood symptoms, particularly among men. Our results support the sickness syndrome theory, but furthermore emphasise the relevance to study immune suppression in bipolar disorder. Due to the explorative nature and cross-sectional design, future studies need to confirm these findings.

Prevalence and correlates of low-grade systemic inflammation in adult psychiatric inpatients: An electronic health record-based study

Low-grade inflammation is a risk factor for depression, psychosis and other major psychiatric disorders. It is associated with poor response to antidepressant and antipsychotics, and could potentially be a treatment target. However, there is limited data on the prevalence of low-grade inflammation in major psychiatric disorders, and on the characteristics of patients who show evidence of inflammation. We examined the prevalence of low-grade inflammation and associated socio-demographic and clinical factors in acute psychiatric inpatients. An anonymised search of the electronic patient records of Cambridgeshire and Peterborough NHS Foundation Trust was used to identify patients aged 18-65 years who were hospitalised between 2013 and 2016 (inclusive). We excluded patients on antibiotics or oral steroids, or with missing data. Inflammation was defined using serum C-reactive protein (>3 mg/L) or total white cell count (>9.4 × 10⁹/L) as measured within 14 days of admission. Out of all 599 admissions, the prevalence of inflammation (serum CRP >3 mg/L) in the ICD-10 diagnostic groups of psychotic disorders (F20-29), mood disorders (F30-39), neurotic disorders (F40-48) and personality disorders (F60-69) was 32%, 21%, 22% and 42%, respectively. In multivariable analyses, low-grade inflammation was associated with older age, black ethnicity, being single, self-harm, diagnoses of schizophrenia, bipolar disorder, current treatments with antidepressants, benzodiazepines, and with current treatment for medical comorbidities. A notable proportion of acutely unwell psychiatric patients from all ICD-10 major diagnostic groups show evidence of low-grade inflammation, suggesting inflammation may be relevant for all psychiatric disorders.

C-reactive protein and white blood cell levels in schizophrenia, bipolar disorders and depression - associations with mortality and psychiatric outcomes: a population-based study

BACKGROUND

Mental disorders have been associated with increased levels of inflammatory markers, which can affect disease trajectories. We aimed to assess levels of C-reactive protein (CRP) and white blood cells (WBC) across individuals with schizophrenia, bipolar disorder, and depression, and to investigate associations with subsequent psychiatric admission and mortality.

METHODS

We identified all adults in the Central Denmark Region during 2000-2012 with a first diagnosis of schizophrenia, bipolar disorder, or depression and a baseline measurement of CRP and/or WBC count. We followed these individuals until outcome of interest (psychiatric admission or death), emigration or December 31, 2012, using Cox regression analysis to estimate hazard ratios (HRs).

RESULTS

Baseline median CRP differed significantly between mental disorders (P=0.01) being highest in individuals with bipolar disorder (3.5mg/L) (particularly during manic states, 3.9mg/L), followed by schizophrenia (3.1mg/L), and depression (2.8mg/L), while baseline WBC count did not differ (median 7.1×10⁹/L). Elevated CRP levels were associated with increased all-cause mortality by adjusted HRs of 1.56 (95% CI: 1.02-2.38) for levels 3-10mg/L and 2.07 (95% CI: 1.30-3.29) for levels above 10mg/L compared to individuals with levels below 3mg/L. WBC counts were not associated with all-cause mortality. No association was observed between levels of the inflammatory markers and subsequent psychiatric admissions.

CONCLUSIONS

People with severe mental disorders had increased inflammatory markers at first diagnosis, and elevated CRP levels were associated with increased mortality. Thorough screening for physical diseases is of utmost importance among individuals who are diagnosed with severe mental disorder.

Do Statins Have Antidepressant Effects?

Statins are used widely in primary and secondary prevention of cardiovascular disease; a treatment effect that has long been thought to be due to their cholesterol-lowering properties. However, statins also have a wide range of anti-inflammatory effects independent of their lipid-lowering mechanisms. In depression, low-grade inflammation is a replicated finding, and several studies have shown antidepressant properties of diverse anti-inflammatory drugs. Large observational studies have suggested reduced risks of depression amongst those taking statins, an effect that is thought to be explained by the anti-inflammatory properties of this class of drugs. Also, preliminary randomized controlled trials (RCTs) have indicated that statins may have adjunctive antidepressant effects when used as add-on treatment to selective serotonin reuptake inhibitors (SSRIs). However, the RCTs were small and limited by low generalizability, and some early observational studies have pointed towards potential neuropsychiatric adverse effects of statin treatment. Nevertheless, based on the good tolerability and general safety of the statins, researchers are currently investigating the potential antidepressant properties of these agents. The present review aims to give an overview on the potential antidepressant effects of statins based on their anti-inflammatory properties, covering topics such as safety versus treatment effects, potential mechanisms of action and the possibility of targeted treatment (precision medicine).