Early life stress and tumor necrosis factor superfamily in crack cocaine withdrawal

Cocaine-use disorder and childhood maltreatment are associated with the activation of neutrophils and increased inflammation

BACKGROUND

Cocaine-use disorder (CUD) has been associated with early life adversity and activated cellular immune responses. Women are most vulnerable to complications from chronic substance disorders, generally presenting an intense feeling of abstinence and consuming significant drug amounts. Here, we investigated neutrophil functional activities in CUD, including the formation of neutrophil extracellular traps (NETs) and related intracellular signalling. We also investigated the role of early life stress in inflammatory profiles.

METHODS

Blood samples, clinical data, and history of childhood abuse or neglect were collected at the onset of detoxification treatment of 41 female individuals with CUD and 31 healthy controls (HCs). Plasma cytokines, neutrophil phagocytosis, NETs, intracellular reactive oxygen species (ROS) generation, and phosphorylated protein kinase B (Akt) and mitogen-activated protein kinases (MAPK)s were assessed by flow cytometry.

RESULTS

CUD subjects had higher scores of childhood trauma than controls. Increased plasma cytokines (TNF-α, IL-1β, IL-6, IL-8, IL-12, and IL-10), neutrophil phagocytosis, and production of NETs were reported in CUD subjects as compared to HC. Neutrophils of CUD subjects also produced high levels of intracellular ROS and had more activated Akt and MAPKs (p38/ERK), which are essential signalling pathways involved in cell survival and NETs production. Childhood trauma scores were significantly associated with neutrophil activation and peripheral inflammation.

CONCLUSION

Our study reinforces that smoked cocaine and early life stress activate neutrophils in an inflammatory environment.

Increased serum levels of tumour necrosis factor-like weak inducer of apoptosis in children with autism spectrum disorder

Introduction: A previous study has evaluated the association between serum tumour necrosis factor-like weak apoptosis inducer (TWEAK) levels and autism spectrum disorder (ASD). In line with this investigation, the present study aimed to measure serum TWEAK levels to determine whether their eventual alteration might have etiopathogenetic significance in children with ASD. Methods: A total of 40 treatment-naive children with ASD and 40 healthy children as controls were included in the present study. The Schedule for Affective Disorders and Schizophrenia for School-Aged Children-Present and Lifetime Version, DSM-5 was used by a psychiatrist to screen the healthy controls for psychiatric disorders after a physical examination by a paediatrician. The clinical severity of the ASD symptoms was assessed by the Childhood Autism Rating Scale. Venous blood samples were collected, and serum TWEAK levels were measured. Results: This study included 80 children in total, with 40 (50.0%) in the patient group and 40 (50.0%) in the healthy control group. Thirty four (85.0%) of the participants in the patient group, and 31 (77.5%) in the healthy control group, were male, and the remainder were female. The distribution of the gender ratio was statistically similar between groups (p = 0.568). The volunteers were between 36 and 59 months old. The average age in the patient group was 46.0 ± 6.5, while that in the healthy control group was 45.2 ± 6.7. The ages were also statistically similar between groups (p = 0.615). The TWEAK values of the patient group were found to be statistically higher than those of the healthy control group (p < 0.001). Discussion: This study examined whether serum TWEAK levels were related to ASD in childhood. Our findings indicate that children with ASD have higher TWEAK levels when compared to other children. The findings further indicate that serum TWEAK levels could be related to ASD etiopathogenesis independent of ASD symptom severity.

Biomarkers of Relapse in Cocaine Use Disorder: A Narrative Review

Introduction: Cocaine use disorder is a chronic disease with severe consequences and a high relapse rate. There is a critical need to explore the factors influencing relapse in order to achieve more efficient treatment outcomes. Furthermore, there is a great need for easy-to-measure, repeatable, and valid biomarkers that can predict treatment response or relapse. Methods: We reviewed the available literature on the Pubmed database concerning the biomarkers associated with relapse in CUD, including central nervous system-derived, genetic, immune, oxidative stress, and “other” biomarkers. Results: Fifty-one articles were included in our analysis. Twenty-five imaging brain anatomic and function assessment studies, mostly using fMRI, examined the role of several structures such as the striatum activity in abstinence prediction. There were fewer studies assessing the use of neuropsychological factors, neurotrophins, or genetic/genomic factors, immune system, or oxidative stress measures to predict abstinence. Conclusion: Several biomarkers have been shown to have predictive value. Prospective studies using combined multimodal assessments are now warranted.

Exploring cannabidiol effects on inflammatory markers in individuals with cocaine use disorder: a randomized controlled trial

Cocaine use disorder (CUD) is a major public health issue associated with physical, social, and psychological problems. Excessive and repeated cocaine use induces oxidative stress leading to a systemic inflammatory response. Cannabidiol (CBD) has gained substantial interest for its anti-inflammatory properties, safety, and tolerability profile. However, CBD anti-inflammatory properties have yet to be confirmed in humans. This exploratory study is based on a single-site randomized controlled trial that enrolled participants with CUD between 18 and 65 years, randomized (1:1) to daily receive either CBD (800 mg) or placebo for 92 days. The trial was divided into a 10-day detoxification (phase I) followed by a 12-week outpatient follow-up (phase II). Blood samples were collected from 48 participants at baseline, day 8, week 4, and week 12 and were analyzed to determine monocytes and lymphocytes phenotypes, and concentrations of various inflammatory markers such as cytokines. We used generalized estimating equations to detect group differences. Participants treated with CBD had lower levels of interleukin-6 (p = 0.017), vascular endothelial growth factor (p = 0.032), intermediate monocytes CD14⁺CD16⁺ (p = 0.024), and natural killer CD56^negCD16^hi (p = 0.000) compared with participants receiving placebo. CD25⁺CD4⁺T cells were higher in the CBD group (p = 0.007). No significant group difference was observed for B lymphocytes. This study suggests that CBD may exert anti-inflammatory effects in individuals with CUD.

Common and disorder-specific upregulation of the inflammatory markers TRAIL and CCL20 in depression and schizophrenia

Schizophrenia (SZ) and major depressive disorder (MDD) are severe mental disorders, which have been associated with alterations of the peripheral inflammatory network. However, studies for both disorders have not been fully consistent and have focused on few canonical markers with high relevance to the innate immune system, while the role of the adaptive immune system is studied less. Furthermore, it is unclear to what extent inflammatory abnormalities are diagnosis-specific or transdiagnostic. The purpose of this study was to investigate 75 peripheral inflammatory markers including the acute phase protein high-sensitivity C-reactive protein (hsCRP) in patients with MDD (n = 37), SZ (n = 42) and healthy controls (HC) (n = 17), while considering possible confounders and correcting rigorously for multiple testing in group comparisons. We identified C–C chemokine ligand 20 (CCL20) and tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) as the inflammatory markers with significant group differences after controlling for multiple comparisons and adjusting for BMI, sex and smoking as confounders. TRAIL was elevated in both MDD and SZ compared to HC. CCL20 was specifically increased in SZ compared to MDD and HC. There were no significant group differences in hsCRP after correcting for multiple testing. Finally, we observed no significant correlations among CCL20, TRAIL and CRP. TRAIL is a transdiagnostic marker for SZ and MDD, with both markers being independent from CRP and body mass index (BMI). CCL20 may be a novel and specific biomarker of schizophrenia, but an influence of antipsychotic medication cannot be excluded. Identifying novel markers in mental disease bears the potential for future research towards novel treatment strategies by modifying inflammation-related processes.

Serum tumor necrosis factor-like weak inducer of apoptosis levels are elevated in schizophrenia

OBJECTIVE

The purpose of this study was to assess serum Tumor necrosis factor-like weak inducer of apoptosis (TWEAK) concentrations to determine whether changes in patients with schizophrenia could have etiopathogenetic importance. Since very little research has addressed the connection between the inflammatory marker TWEAK and schizophrenia, we wanted to examine alterations of TWEAK and investigate the possible correlation between clinical symptomatology and serum concentrations.

METHODS

A total of 45 schizophrenia patients and 40 healthy controls were included in this study. The Positive Symptom Assessment scale and the Negative Symptom Assessment scale were administered to determine symptom severity. Venous blood samples were collected and serum TWEAK levels were measured.

RESULTS

Serum TWEAK levels were significantly higher in the schizophrenia group than the control group, independently of potential confounders, including sex, age, body mass index and smoking status.

CONCLUSION

The results indicate that TWEAK is elevated in schizophrenia patients, which could deepen our understanding of the role of inflammation in the pathogenesis of schizophrenia.

Effects of early life stress on cocaine conditioning and AMPA receptor composition are sex-specific and driven by TNF

Exposure to early life adversity can predispose adolescents to the formation of substance abuse disorders. In rodents, early stressors such as repeated maternal separation (MS) impact AMPAR activity in the prefrontal cortex (PFC) and nucleus accumbens (NAc), regions involved in drug-cue association after cocaine-induced conditioned place preference (CPP). Notably, previous reports suggest that the pro-inflammatory cytokine tumor necrosis factor (TNF) regulates AMPAR subunit composition; increased TNF levels are reported to reduce GluA2-positive AMPARs. Since MS can elevate adolescent TNF levels, the stressor may therefore alter AMPAR subunit composition via neuroimmune signaling, thereby affecting cocaine-induced CPP. We tested the specific role of soluble TNF in MS-induced GluA2 loss and cocaine-induced CPP with biologic disruption of TNF signaling. TNF gene and protein expression were elevated in both PFC and NAc of MS males, but not females. GluA2 expression was reduced in both regions in only male MS rats, and systemic treatment with either ibudilast - a phosphodiesterase inhibitor, or XPro1595 - a blood-brain barrier-permeable blocker of soluble TNF - reversed such loss. MS males also formed greater preference for a cocaine-paired environment, the expression of which returned to control levels after XPro1595 administration. These data suggest a sex-specific mechanistic link between TNF signaling and changes in GluA2 expression and drug-cue conditioning, thereby providing further evidence for a role of MS and neuro-immune activity in cortical and striatal AMPAR changes. Moreover, manipulation of the TNF signaling pathway represents a novel approach for influencing response to reinforcing effects of drug use.

Anhedonia in cocaine use disorder is associated with inflammatory gene expression

Treatments for Cocaine Use Disorder (CUD) are variably effective, and there are no FDA-approved medications. One approach to developing new treatments for CUD may be to investigate and target poor prognostic signs. One such sign is anhedonia (i.e. a loss of pleasure or interest in non-drug rewards), which predicts worse outcomes in existing CUD treatments. Inflammation is thought to underlie anhedonia in many other disorders, but the relationship between anhedonia and inflammation has not been investigated in CUD. Therefore, we assessed peripheral genome-wide gene expression in n = 48 individuals with CUD with high (n = 24) vs. low (n = 24) levels of anhedonia, defined by a median split of self-reported anhedonia. Our hypothesis was that individuals with high anhedonia would show differential gene expression in inflammatory pathways. No individual genes were significantly different between the low and high anhedonia groups when using t-tests with a stringent false discovery rate correction (FDR-corrected p < 0.05). However, an exploratory analysis identified 166 loci where t-tests suggested group differences at a nominal p < 0.05. We used DAVID, a bioinformatics tool that provides functional interpretations of complex lists of genes, to examine representation of this gene list in known pathways. It confirmed that mechanisms related to immunity were the top significant associations with anhedonia in the sample. Further, the two top differentially expressed genes in our sample, IRF1 and GBP5, both have primary inflammation and immune functions, and were significantly negatively correlated with total scores on our self-report of anhedonia across all 48 subjects. These results suggest that prioritizing development of anti-inflammatory medications for CUD may pay dividends, particularly in combination with treatment-matching strategies using either phenotypic measures of anhedonia or biomarkers of inflammatory gene expression to individualize treatment.

Serum TNF-related weak inducer of apoptosis (TWEAK) and TNF-related apoptosis-inducing ligand (TRAIL) levels of patients with bipolar disorder in manic episode, in remission and healthy controls

TNF-related weak inducer of apoptosis (TWEAK) and TNF-related apoptosis-inducing ligand (TRAIL) are members of TNF superfamily, which has various roles in immunologic and inflammatory reactions in the organism. Pathophysiology in bipolar disorder is still under investigation and altered serum levels of cytokines are often encountered. Aim of this study is to detect serum TWEAK and TRAIL levels of patients with bipolar disorder and healthy controls. For this purpose, 55 patients with bipolar disorder -27 manic episode (ME), 28 remission (RE) and 29 healthy controls (HC) were included. TWEAK levels of ME and RE groups were significantly lower than HC. TWEAK levels of bipolar patients (BP) were also lower than HC. TRAIL levels of ME, RE, HC groups and BP, HC groups were statistically similar. In our knowledge, this is the first study concerning about TWEAK and TRAIL levels in bipolar disorder and our results pointed that TWEAK-related immune response might be impaired in bipolar disorder, but our study fails to eradicate the confounders such as medication, smoking and body mass index. Studies having larger samples and limited confounders are needed to be able to evaluate these changes better and detect possible alterations about TRAIL and other TNF superfamily members.

Evidence for Immune Activation and Resistance to Glucocorticoids Following Childhood Maltreatment in Adolescents Without Psychopathology

Early-life stress (ELS) increases the risk for psychopathology. Immune and endocrine changes have been reported in adults and are associated with maladaptation of stress-responsive systems. Here we investigated the effects of ELS on endocrine and immune pathways in adolescents without psychopathology. Thirty adolescents with a history of childhood maltreatment and 27 adolescents without ELS history were recruited. Blood and hair samples were obtained from all participants. Lymphocytes were isolated and stimulated in vitro. Flow cytometry was used to evaluate lymphocyte subsets, Th1/Th2/Th17 cytokines, mitogen-activated protein kinase (MAPK), and nuclear factor kappa B (NF-κB) signaling pathways, as well as lymphocyte sensitivity to dexamethasone. Brain-derived neurotrophic factor (BDNF) and hair cortisol were assessed with enzyme-linked immunosorbent assays (ELISAs). Adolescents with a history of ELS had increased percentages of T-cell activation markers (CD3+CD4+CD25+ and CD3+CD69+) and senescent T cells (CD8+CD28- and CD4+CD28-), as well as decreased percentages of NK (CD3-CD56+) and NK T cells (CD3+CD56+). Following stimulation, lymphocytes of ELS+ adolescents produced significantly more IL-2, IL-4, IFN-γ, and IL-17 and engaged more MAPK ERK and NF-κB signaling. ELS was associated with increased hair cortisol levels in parallel with increased lymphocyte resistance to dexamethasone and low plasma BDNF levels. These data provide the first indication of the presence of immune activation and pro-inflammatory profiles in healthy adolescents exposed to ELS, which could contribute to increased vulnerability of trauma-related psychopathology later in life. The underlying mechanisms of this impairment may include the enhanced activation of both MAPK and NF-κB signaling in parallel to partial resistance to glucocorticoids.

Plasma Levels of Tumor Necrosis Factor Superfamily Molecules Are Increased in Bipolar Disorder

Objective

Patients with bipolar disorder (BD) exhibit peripheral low-grade inflammation. The aim of the current study was to investigate the involvement of hitherto unexplored components of the tumor necrosis factor (TNF) superfamily in BD.

Methods

Eighty patients with type I BD and 50 healthy controls matched for age and gender were enrolled in this study. All subjects were assessed with the Mini-Plus to evaluate psychiatric comorbidities; the Young Mania Rating Scale and the Hamilton Depression Rating Scale to evaluate manic and depressive symptoms severity, respectively. TNF superfamily molecules (TNF, TNF-related weak inducer of apoptosis [TWEAK], TNF-related apoptosis-inducing ligand [TRAIL], soluble TNF receptor type 1 [sTNFR1], and soluble TNF receptor type 2 [sTNFR2]) levels were measured by ELISA.

Results

Patients with BD, regardless of mood state, presented increased plasma levels of sTNFR1 and TWEAK in comparison with controls.

Conclusion

These findings corroborate the view that TNF superfamily may play a role in BD pathophysiology.

Social threat exposure in juvenile mice promotes cocaine-seeking by altering blood clotting and brain vasculature

Childhood maltreatment is associated with increased severity of substance use disorder and frequent relapse to drug use following abstinence. However, the molecular and neurobiological substrates that are engaged during early traumatic events and mediate the greater risk of relapse are poorly understood and knowledge of risk factors is to date extremely limited. In this study, we modeled childhood maltreatment by exposing juvenile mice to a threatening social experience (social stressed, S‐S). We showed that S‐S experience influenced the propensity to reinstate cocaine‐seeking after periods of withdrawal in adulthood. By exploring global gene expression in blood leukocytes we found that this behavioral phenotype was associated with greater blood coagulation. In parallel, impairments in brain microvasculature were observed in S‐S mice. Furthermore, treatment with an anticoagulant agent during withdrawal abolished the susceptibility to reinstate cocaine‐seeking in S‐S mice. These findings provide novel insights into a possible molecular mechanism by which childhood maltreatment heightens the risk for relapse in cocaine‐dependent individuals.

Crack cocaine addiction, early life stress and accelerated cellular aging among women

BACKGROUND

Early life stress (ELS) and addiction are related to age-related diseases and telomere shortening. However, the role of telomere length (TL) in crack cocaine addiction remains unknown. The purpose of this study was to investigate the TL in a sample of crack cocaine dependent-women who reported an ELS history and in a community-based sample of elderly women as a reference group for senescence.

METHODS

This study included treatment seeking crack cocaine dependents women (n=127) and elderly women without a psychiatric diagnosis (ELD, n=49). The crack cocaine sample was divided in two groups according to their Childhood Trauma Questionnaire (CTQ) scores: presence of history of childhood abuse and neglect (CRACK-ELS) and absence of ELS history (CRACK). TL was assessed by T/S ratio obtained from peripheral blood DNA using quantitative PCR assay.

RESULTS

CRACK and CRACK-ELS subjects exhibited shortened TL in comparison to the ELD group, despite their younger age. Among crack cocaine sample, CRACK-ELS group had significantly shorter telomeres than the CRACK group. Correlation analysis within crack cocaine group indicated that TL was negatively correlated with emotional abuse scores.

CONCLUSIONS

These results support previous findings associating telomere shortening with both ELS and drug addiction. This study suggests new evidence of a distinct biological phenotype for drug-dependent women with ELS. The results support the biological senescence hypothesis underpinning ELS experience.

Distinct behavioral and immunoendocrine parameters during crack cocaine abstinence in women reporting childhood abuse and neglect

AIM

To assess plasma levels of cortisol and cytokines between cocaine-dependent women with and without childhood maltreatment (CM) history during cocaine detoxification treatment.

METHOD

We assessed immunoendocrine and clinical parameters of 108 crack cocaine female users during 3 weeks of inpatient detoxification treatment, and 24 healthy women to obtain reference values. Women with (CM+, n=53) or without (CM-, n=55) CM history were identified answering the Childhood Trauma Questionnaire (CTQ). Blood samples and clinical assessment were collected before lunch during the first, second and third week post-treatment admission. Flow cytometry was used to assess TNF-α, IFN-γ, IL-2, IL-4, IL-6, IL-10, IL-17A plasma levels and ELISA assay was used to measure plasma cortisol levels.

RESULTS

At baseline, lower Th1 and Th17-related cytokines levels and higher Th2 cytokines levels were observed in crack cocaine users compared with reference values. Cytokines levels of cocaine dependents gradually became closer to reference values along detoxification treatment. However, when CM+ and CM- groups were compared, increased levels of IL-6, IL-4 and TNF-α across time were observed in CM+ group only. Additionally, a Th1/Th2 immune imbalance was observed within CM+ group, which was negatively correlated with the severity of the crack withdrawal. Finally, loading trauma exposure severity, immunoendocrine and clinical parameters in factor analysis, we identified three clusters of observed variables during detoxification: (1) systemic immunity and trauma exposure, (2) pro-inflammatory immunity and (3) behavior

CONCLUSION

Our results suggest the existence of an immunological phenotype variant associated with CM exposure during crack cocaine detoxification of women.

Clinical perspectives of TRAIL: insights into central nervous system disorders

The TNF-related apoptosis inducing ligand TRAIL is a member of the TNF superfamily that has been firstly studied and evaluated for its anti-cancer activity, and the insights into its biology have already led to the identification of several TRAIL-based anticancer strategies with strong clinical therapeutic potentials. Nonetheless, the TRAIL system is far more complex and it can lead to a wider range of biological effects other than the ability of inducing apoptosis in cancer cells. By virtue of the different receptors and the different signalling pathways involved, TRAIL plays indeed a role in the regulation of different processes of the innate and adaptive immune system and this feature makes it an intriguing molecule under consideration in the development/progression/treatment of several immunological disorders. In this context, central nervous system represents a peculiar anatomic site where, despite its "status" of immune-privileged site, both innate and adaptive inflammatory responses occur and are involved in several pathological conditions. A number of studies have evaluated the role of TRAIL and of TRAIL-related pathways as pro-inflammatory or protective stimuli, depending on the specific pathological condition, confirming a twofold nature of this molecule. In this light, the aim of this review is to summarize the main preclinical evidences of the potential/involvement of TRAIL molecule and TRAIL pathways for the treatment of central nervous system disorders and the key suggestions coming from their assessment in preclinical models as proof of concept for future clinical studies.

Resveratrol fails to affect cocaine conditioned place preference behavior, but alleviates anxiety-like behaviors in cocaine withdrawn rats

RATIONALE

Resveratrol participates in regulating abnormal behaviors in psychostimulant-exposed animals.

OBJECTIVES

To examine effects of resveratrol on relapse and anxiety-like behaviors in cocaine withdrawn rats and to investigate possible molecular mechanisms underlying resveratrol effects in hippocampus (HP) and prefrontal cortex (PFC).

METHODS

Conditioned place preference (CPP) assay and elevated plus maze (EPM) test were used to examine cocaine CPP behavior and anxiety-like behaviors in rats, respectively. Resveratrol was administrated to cocaine withdrawn rats. Levels of MDA, GSH and SOD were examined to evaluate oxidative status, and levels of IL-6, IL-1β and TNF α were measured to examine inflammatory status and levels of caspase-3 and BAX was examined to evaluate apoptotic status in HP and PFC. SIRT expression was also examined here.

RESULTS

Resveratrol did not affect cocaine CPP behaviors, but attenuated anxiety-like behaviors in cocaine withdrawn rats. Levels of MDA and TNFα in PFC, and levels of MDA, SOD, GSH, IL-6, IL-1β, TNFα, caspase-3 and BAX in HP, but not SIRT1 expression in both regions were significantly changed during cocaine withdrawal period. Except SOD, resveratrol reversed above neurochemical changes induced by cocaine withdrawal. Furthermore, RSV induced a greater upregulation of SIRT1 expression in PFC in cocaine withdrawn rats than that in saline controls.

CONCLUSIONS

Current findings suggest that resveratrol may influence behaviors in cocaine withdrawn rats. Oxidative stress, inflammation, apoptosis, and SIRT1 signaling pathway in HP or PFC might be involved in mediating effects of RSV on behaviors in cocaine withdrawn rats.

Inflammation, neurotrophism and oxidative stress and childhood psychopathology in a large community sample

OBJECTIVE

To investigate the association between peripheral biomarkers and child psychopathology in a large community sample.

METHOD

A total of 625 aged 6- to 13-year old subjects were recruited from a community school-based study. Psychopathology was assessed using the Child Behaviour Checklist (CBCL). Psychiatric diagnosis was evaluated using the Development and Well-Being Assessment. The following biomarkers were examined in peripheral blood: brain-derived neurotrophic factor, cytokines (IL-2, IL-4, IL-6, IL-10, IL-17, IFN-g, and TNF-α), chemokines (eotaxin/CCL11, IP-10, MCP-1), cytokine receptors (sTNFR1 and sTNFR2), and the oxidative stress marker TBARS.

RESULTS

We found significant associations between sTNFR2, eotaxin/CCL11 and CBCL total score, as well as with specific dimensions of psychopathology. There were different patterns of association between these biomarkers and psychological and behavioural symptoms in children with and without a mental disorder. TBARS, IL-6 and MCP-1 were more specific to some clusters of symptoms in children with a psychiatric diagnosis.

CONCLUSION

Our data support the potential use of biomarkers, especially those involved in immune-inflammatory pathways, in investigating neurodevelopmental psychopathology. Their association with different dimensions of symptoms might be of useful when analyzing illness severity and clusters of symptoms within specific disorders.

TNF-related weak inducer of apoptosis (TWEAK) levels in schizophrenia

Members of tumor necrosis factor (TNF) superfamily have roles in many biological events and pathogenesis of central nervous system (CNS) diseases. A relatively recently found member of this family, TNF-related weak inducer of apoptosis (TWEAK) have importance both in development of pathological CNS processes and as a target for the treatment of these diseases. The aim of this study was to investigate whether TWEAK's plasma levels are different in patients with schizophrenia. For this purpose plasma TWEAK levels of 44 patients diagnosed with schizophrenia and control group of 40 healthy individuals were compared. Although numerical difference was found between TWEAK levels of patients and controls it was not statistically significant. When we tested for female and male patients and controls seperately, TWEAK levels of male patients were significantly lower than male controls. As far as we know this is the first study that investigates levels of TWEAK in patients with schizophrenia. Although we did not find statistically significant results in our study, we believe that difference could be found in future studies with higher number of subjects. Researches with non-studied TNF superfamily members like TWEAK and TNF-related apoptosis-inducing ligand (TRAIL) could contribute to the understanding of immune-cytokine related hypotheses of schizophrenia.