Social anxiety disorder-associated gut microbiota increases social fear.

Social anxiety disorder (SAD) is a crippling psychiatric disorder characterized by intense fear or anxiety in social situations and their avoidance. However, the underlying biology of SAD is unclear and better treatments are needed. Recently, the gut microbiota has emerged as a key regulator of both brain and behaviour, especially those related to social function. Moreover, increasing data supports a role for immune function and oxytocin signalling in social responses. To investigate whether the gut microbiota plays a causal role in modulating behaviours relevant to SAD, we transplanted the microbiota from SAD patients, which was identified by 16S rRNA sequencing to be of a differential composition compared to healthy controls, to mice. Although the mice that received the SAD microbiota had normal behaviours across a battery of tests designed to assess depression and general anxiety-like behaviours, they had a specific heightened sensitivity to social fear, a model of SAD. This distinct heightened social fear response was coupled with changes in central and peripheral immune function and oxytocin expression in the bed nucleus of the stria terminalis. This work demonstrates an interkingdom basis for social fear responses and posits the microbiome as a potential therapeutic target for SAD.

Gut Microbiome Composition and Its Association with Sleep in Major Psychiatric Disorders.

INTRODUCTION: Sleep disturbances are highly prevalent across most major psychiatric disorders. Alterations in the hypothalamic-pituitary-adrenal axis, neuroimmune mechanisms, and circadian rhythm disturbances partially explain this connection. The gut microbiome is also suspected to play a role in sleep regulation, and recent studies suggest that certain probiotics, prebiotics, synbiotics, and fecal microbiome transplantation can improve sleep quality. METHODS: We aimed to assess the relationship between gut-microbiota composition, psychiatric disorders, and sleep quality in this cross-sectional, cross-disorder study. We recruited 103 participants, 63 patients with psychiatric disorders (major depressive disorder [n = 31], bipolar disorder [n = 13], psychotic disorder [n = 19]) along with 40 healthy controls. Sleep quality was assessed with the Pittsburgh Sleep Quality Index (PSQI). The fecal microbiome was analyzed using 16S rRNA sequencing, and groups were compared based on alpha and beta diversity metrics, as well as differentially abundant species and genera. RESULTS: A transdiagnostic decrease in alpha diversity and differences in beta diversity indices were observed in psychiatric patients, compared to controls. Correlation analysis of diversity metrics and PSQI score showed no significance in the patient and control groups. However, three species, Ellagibacter isourolithinifaciens, Senegalimassilia faecalis, and uncultured Blautia sp., and two genera, Senegalimassilia and uncultured Muribaculaceae genus, were differentially abundant in psychiatric patients with good sleep quality (PSQI >8), compared to poor-sleep quality patients (PSQI ≤8). CONCLUSION: In conclusion, this study raises important questions about the interconnection of the gut microbiome and sleep disturbances.

The Muscle-Gut-Brain Axis and Psychiatric Illness.

The microbiota-gut-brain axis (MGBA) has been the subject of much research over the past decade, offering an exciting new paradigm for the treatment of psychiatric disorders. In this review, the MGBA is extended to include skeletal muscle and the potential role of an expanded "muscle-gut-brain axis" (MuGBA) in conditions such as anxiety and depression is discussed. There is evidence, from both preclinical and human studies, of bidirectional links between the gut microbiome and skeletal muscle function and structure. The therapeutic role of exercise in reducing depressive and anxiety symptoms is widely recognised, and the potential role of the gut microbiota-skeletal muscle link is discussed within this context. Potential pathways of communication involved in the MuGBA including the tryptophan-kynurenine pathway, intestinal permeability, immune modulation, and bacterial metabolites such as short-chain-fatty-acids are explored.

The gut microbiome in social anxiety disorder: evidence of altered composition and function.

The microbiome-gut-brain axis plays a role in anxiety, the stress response and social development, and is of growing interest in neuropsychiatric conditions. The gut microbiota shows compositional alterations in a variety of psychiatric disorders including depression, generalised anxiety disorder (GAD), autism spectrum disorder (ASD) and schizophrenia but studies investigating the gut microbiome in social anxiety disorder (SAD) are very limited. Using whole-genome shotgun analysis of 49 faecal samples (31 cases and 18 sex- and age-matched controls), we analysed compositional and functional differences in the gut microbiome of patients with SAD in comparison to healthy controls. Overall microbiota composition, as measured by beta-diversity, was found to be different between the SAD and control groups and several taxonomic differences were seen at a genus- and species-level. The relative abundance of the genera Anaeromassillibacillus and Gordonibacter were elevated in SAD, while Parasuterella was enriched in healthy controls. At a species-level, Anaeromassilibacillus sp An250 was found to be more abundant in SAD patients while Parasutterella excrementihominis was higher in controls. No differences were seen in alpha diversity. In relation to functional differences, the gut metabolic module 'aspartate degradation I' was elevated in SAD patients. In conclusion, the gut microbiome of patients with SAD differs in composition and function to that of healthy controls. Larger, longitudinal studies are warranted to validate these preliminary results and explore the clinical implications of these microbiome changes.

Advances in the gut microbiome and mood disorders.

PURPOSE OF REVIEW: The gut microbiome is in constant bidirectional communication with the brain through the microbiota-gut-brain-axis. Mood disorders are among the most common psychiatric disorders and include major depressive disorder and bipolar disorder. The gut microbiome is altered in individuals with mood disorders and has a role in its inflammatory pathophysiology. In this article, we performed a narrative review of clinical studies, randomized controlled trials and meta-analyses addressing advances in gut microbiome research in mood disorders and included articles that were published between 2021 and 2022. RECENT FINDINGS: Studies highlight transdiagnostic alterations of microbiota in mood disorders, with reductions of butyrate-producing bacteria. Participants with major depressive disorder showed altered beta-diversity, while participants with bipolar disorder showed reduced alpha-diversity. Both disorders exhibit alterations in the metabolome. Early pilot studies addressed the possibility of using the gut microbiome for the prediction of treatment response and the blood microbiome for the diagnosis of psychiatric disorders. Findings from clinical trials support the use of probiotics as an add-on therapy for major depressive disorder. The second published case report in the literature reported a favourable outcome of a patient with bipolar disorder after faecal microbiota transplantation. SUMMARY: Gut microbiome modulations allow new treatment strategies including the use of psychobiotics for the treatment and prevention of mood disorders. Well designed clinical trials aiming for personalized medicine are needed to investigate the efficacy and safety of psychobiotic interventions.

Cardiac vagal activity is associated with gut-microbiome patterns in women-An exploratory pilot study.

Introduction: A functional reciprocity between the gut microbiome and vagal nerve activity has been suggested, however, human studies addressing this phenomenon are limited. Methods: Twenty-four-hour cardiac vagal activity (CVA) was assessed from 73 female participants (aged 24.5 ± 4.3 years). Additionally, stool samples were subjected to 16SrRNA gene analysis (V1-V2). Quantitative Insights Into Microbial Ecology (QIIME) was used to analyse microbiome data. Additionally, inflammatory parameters (such as CRP and IL-6) were derived from serum samples. Results: Daytime CVA correlated significantly with gut microbiota diversity (r sp = 0.254, p = 0.030), CRP (r sp = -0.348, p = 0.003), and IL-6 (r sp = -0.320, p = 0.006). When the group was divided at the median of 24 h CVA (Mdn = 1.322), the following features were more abundant in the high CVA group: Clostridia (Linear discriminant analysis effect size (LDA) = 4.195, p = 0.029), Clostridiales (LDA = 4.195, p = 0.029), Lachnospira (LDA = 3.489, p = 0.004), Ruminococcaceae (LDA = 4.073, p = 0.010), Faecalibacterium (LDA = 3.982, p = 0.042), Lactobacillales (LDA = 3.317, p = 0.029), Bacilli (LDA = 3.294, p = 0.0350), Streptococcaceae (LDA = 3.353, p = 0.006), Streptococcus (LDA = 3.332, p = 0.011). Based on Dirichlet multinomial mixtures two enterotypes could be detected, which differed significantly in CVA, age, BMI, CRP, IL-6, and diversity. Conclusions: As an indicator of gut-brain communication, gut microbiome analysis could be extended by measurements of CVA to enhance our understanding of signalling via microbiota-gut-brain-axis and its alterations through psychobiotics.

Oxidative Status in Adult Anorexia Nervosa Patients and Healthy Controls-Results from a Cross-Sectional Pilot Study.

Oxidative stress describes an imbalance of reactive oxygen species (ROS) and antioxidative defence systems. Recently, the consequences of oxidative stress have become a central field of research and have been linked to the genesis of multiple psychiatric diseases. Some oxidative stress parameters have not been investigated before in anorexia nervosa (AN) patients, including the gut microbiota-derived metabolite trimethylamine N-oxide (TMAO) and polyphenols (PPm). In this cross-sectional pilot study, we evaluated these markers together with total peroxides (TOC), antioxidative capacity (TAC), endogenous peroxidase activity (EPA) and antibodies against oxidized LDL (oLAb) in serum samples of 20 patients with AN compared to 20 healthy controls. The antioxidative capacity was significantly decreased in AN patients, with a mean TAC of 1.57 mmol/L (SD: ±0.62); t (34) = -2.181, p = 0.036) compared to HC (mean = 1.91 mmol/L (SD: ±0.56), while the other investigated parameters were not significantly different between the two groups. In AN patients, TAC correlated with EPA (rsp = -0.630, p = 0.009). This study suggests that there is an antioxidative deficiency in AN patients. In this respect, there is a demand for interventional studies to determine whether antioxidants can be used as add-on therapy in the treatment of AN.

The immune-kynurenine pathway in social anxiety disorder.

BACKGROUND: The tryptophan-kynurenine pathway is of major interest in psychiatry and is altered in patients with depression, schizophrenia and panic disorder. Stress and immune alterations can impact this system, through cortisol- and cytokine-induced activation. In addition, there is emerging evidence that the kynurenine pathway is associated with suicidality. There have been no studies to date exploring the immune-kynurenine system in social anxiety disorder (SAD), and indeed very limited human studies on the kynurenine pathway in any clinical anxiety disorder. METHODS: We investigated plasma levels of several kynurenine pathway markers, including kynurenine (KYN), tryptophan (TRYP) and kynurenic acid (KYNA), along with the KYN/TRYP and KYNA/KYN ratios, in a cohort of 32 patients with SAD and 36 healthy controls. We also investigated a broad array of both basal and lipopolysaccharide (LPS)-stimulated blood cytokine levels including IFN-γ, interleukin (IL)-10, IL-1ß, IL-2, IL-4, IL-6, IL-8 and tumor necrosis factor (TNF)-α. RESULTS: SAD patients had elevated plasma KYNA levels and an increased KYNA/KYN ratio compared to healthy controls. No differences in KYN, TRYP or the KYN/TRYP ratio were seen between the two groups. SAD patients with a history of past suicide attempt showed elevated plasma KYN levels and a higher KYN/TRYP ratio compared to patients without a history of suicide attempt. No differences were seen in basal or LPS-stimulated pro-inflammatory cytokine levels between the patients and controls. However, unstimulated IL-10, an anti-inflammatory cytokine, was significantly lower in the SAD group. A significant sex influence was evident with SAD males having lower levels of IL-10 compared to healthy males but no difference seen between SAD females and healthy females. CONCLUSIONS: The peripheral kynurenine pathway is altered in SAD and preferentially directed towards KYNA synthesis. Additionally, kynurenine pathway activation, as evidenced by elevated KYN and KYN/TRYP ratio, is evident in SAD patients with a history of past suicide attempt. While no differences in pro-inflammatory cytokines is apparent in SAD patients, lower anti-inflammatory IL-10 levels are seen in SAD males. Further investigation of the role of the immune-kynurenine pathway in SAD and other clinical anxiety disorders is warranted.

Psychobiotics: Evolution of Novel Antidepressants.

The gut-brain axis is a bidirectional communication system which allows the central nervous system and gastrointestinal tract to interact with and respond to each other rapidly and effectively. It is becoming increasingly clear that major players in this complex system are gut bacteria. The mechanisms of signal transmission from bacteria to the brain are complex and not fully elucidated, but include neural, endocrine, immune, and metabolic pathways. It was initially demonstrated in a rodent model of depression that the gut microbiota was altered. This observation has been replicated in patients with major depression who show decreased microbial diversity. Furthermore, when rodents receive a microbiota transplant from a depressed patient their behaviour alters, as does their tryptophan metabolism and immune status. Several studies of psychobiotics (bacteria with a potential mental health benefit) have been conducted in healthy populations and in patients with depression. While some psychobiotics have shown efficacy in treating depression, other bacteria have yielded negative findings. Larger-scale, well-designed studies are required. EU-funded guidelines recommend that patients with depression or vulnerability to depression should be encouraged to enhance a plant-based diet with a high content of grains/fibres, fermented foods, and fish. A significant impact of such a diet is likely mediated through the gut microbiota.

'An Apple a Day'?: Psychiatrists, Psychologists and Psychotherapists Report Poor Literacy for Nutritional Medicine: International Survey Spanning 52 Countries.

Nutritional interventions have beneficial effects on certain psychiatric disorder symptomatology and common physical health comorbidities. However, studies evaluating nutritional literacy in mental health professionals (MHP) are scarce. This study aimed to assess the across 52 countries. Surveys were distributed via colleagues and professional societies. Data were collected regarding self-reported general nutrition knowledge, nutrition education, learning opportunities, and the tendency to recommend food supplements or prescribe specific diets in clinical practice. In total, 1056 subjects participated in the study: 354 psychiatrists, 511 psychologists, 44 psychotherapists, and 147 MHPs in-training. All participants believed the diet quality of individuals with mental disorders was poorer compared to the general population (p < 0.001). The majority of the psychiatrists (74.2%) and psychologists (66.3%) reported having no training in nutrition. Nevertheless, many of them used nutrition approaches, with 58.6% recommending supplements and 43.8% recommending specific diet strategies to their patients. Only 0.8% of participants rated their education regarding nutrition as 'very good.' Almost all (92.9%) stated they would like to expand their knowledge regarding 'Nutritional Psychiatry.' There is an urgent need to integrate nutrition education into MHP training, ideally in collaboration with nutrition experts to achieve best practice care.

Sleep and Microbiome in Psychiatric Diseases.

OBJECTIVES: Disturbances in the gut-brain barrier play an essential role in the development of mental disorders. There is considerable evidence showing that the gut microbiome not only affects digestive, metabolic and immune functions of the host but also regulates host sleep and mental states through the microbiota-gut-brain axis. The present review summarizes the role of the gut microbiome in the context of circadian rhythms, nutrition and sleep in psychiatric disorders. METHODS: A PubMed search (studies published between April 2015-April 2020) was conducted with the keywords: "sleep, microbiome and psychiatry"; "sleep, microbiome and depression"; "sleep, microbiome and bipolar disorder", "sleep, microbiome and schizophrenia", "sleep, microbiome and anorexia nervosa", "sleep, microbiome and substance use disorder", "sleep, microbiome and anxiety"; "clock gene expression and microbiome", "clock gene expression and nutrition". Only studies investigating the relationship between sleep and microbiome in psychiatric patients were included in the review. RESULTS: Search results yielded two cross-sectional studies analyzing sleep and gut microbiome in 154 individuals with bipolar disorder and one interventional study analyzing the effect of fecal microbiota transplantation in 17 individuals with irritable bowel syndrome on sleep. In patients with bipolar disorder, Faecalibacterium was significantly associated with improved sleep quality scores and a significant correlation between Lactobacillus counts and sleep. CONCLUSION: Translational research on this important field is limited and further investigation of the bidirectional pathways on sleep and the gut microbiome in mood disorders is warranted.

Correction to: Probiotics and the Microbiota-Gut-Brain Axis: Focus on Psychiatry.

The original version of this article unfortunately contained mistake. The sure name "Cyran" of the author John F Cyran (J. F. Cyran) should be corrected to read John F. Cryan (J. F. Cryan) as presented above.

Personality Structure and Attachment in Bipolar Disorder.

BACKGROUND: An impairment of self and interpersonal functioning has an impact on coping strategies, regulation of affect and stress. Little is known so far about the impairment of personality functioning in patients with bipolar disorder (BD). The aim of this study is to assess the effects of personality structure and attachment in BD patients on the symptom burden. METHODS: Forty-six patients with the diagnosis of BD were assessed by the 12-item Operationalized Psychodynamic Diagnosis Structure Questionnaire (OPD-SQS), the short version of Experience in Close Relationship-revised (ECR-R-D), and the Brief Symptom Inventory-18 (BSI 18) to determine the level of personality functioning, attachment patterns, and symptom load. RESULTS: We observed positive correlations between personality difficulties, insecure attachment, and symptom load in patients with BD. A low level of structural integration and an insecure attachment style in patients with BD were accompanied by a significantly higher symptom load (r = 0.66, p ≤ 0.01). Interestingly, there were no significant differences in the structural integration (T(1.44) = -0.93, p = 0.357) and in the attachment style attachment related avoidance: (T(1,44) = 1.50, p = 0.140); attachment related anxiety (T(1,44) = -0.781, p = 0.439) of study participants with BD when compared to the normative value of the general population. LIMITATIONS: Our limitations are the small sample size of our group and the lack of a control group. CONCLUSION: In general, our results suggest that there is a link between personality structure and affective dynamics including depressive, anxiety, and somatization symptoms in BD. These findings underline the increasing importance of assessing personality structure and attachment for diagnosis and treatment planning of BD.

Recipe for a Healthy Gut: Intake of Unpasteurised Milk Is Associated with Increased Lactobacillus Abundance in the Human Gut Microbiome.

INTRODUCTION: The gut microbiota plays a role in gut-brain communication and can influence psychological functioning. Diet is one of the major determinants of gut microbiota composition. The impact of unpasteurised dairy products on the microbiota is unknown. In this observational study, we investigated the effect of a dietary change involving intake of unpasteurised dairy on gut microbiome composition and psychological status in participants undertaking a residential 12-week cookery course on an organic farm. METHODS: Twenty-four participants completed the study. The majority of food consumed during their stay originated from the organic farm itself and included unpasteurised milk and dairy products. At the beginning and end of the course, participants provided faecal samples and completed self-report questionnaires on a variety of parameters including mood, anxiety and sleep. Nutrient intake was monitored with a food frequency questionnaire. Gut microbiota analysis was performed with 16S rRNA gene sequencing. Additionally, faecal short chain fatty acids (SCFAs) were measured. RESULTS: Relative abundance of the genus Lactobacillus increased significantly between pre- and post-course time points. This increase was associated with participants intake of unpasteurised milk and dairy products. An increase in the faecal SCFA, valerate, was observed along with an increase in the functional richness of the microbiome profile, as determined by measuring the predictive neuroactive potential using a gut-brain module approach. CONCLUSIONS: While concerns in relation to safety need to be considered, intake of unpasteurised milk and dairy products appear to be associated with the growth of the probiotic bacterial genus, Lactobacillus, in the human gut. More research is needed on the effect of dietary changes on gut microbiome composition, in particular in relation to the promotion of bacterial genera, such as Lactobacillus, which are recognised as being beneficial for a range of physical and mental health outcomes.

Probiotics and the Microbiota-Gut-Brain Axis: Focus on Psychiatry.

PURPOSE OF REVIEW: Probiotics are living bacteria, which when ingested in adequate amounts, confer health benefits. Gut microbes are suggested to play a role in many psychiatric disorders and could be a potential therapeutic target. Between the gut and the brain, there is a bi-directional communication pathway called the microbiota-gut-brain axis. The purpose of this review is to examine data from recent interventional studies focusing on probiotics and the gut-brain axis for the treatment of depression, anxiety and schizophrenia. RECENT FINDINGS: Probiotics are likely to improve depression but not schizophrenia. Regarding anxiety, there is only one trial which showed an effect of a multispecies probiotic. However, determinants like the duration of treatment, dosage and interactions have not been thoroughly investigated and deserve more scientific attention. Microbiome-based therapies such as probiotics could be cautiously recommended for depression to enhance beneficial bacteria in the gut and to improve mood through the gut-brain axis.

Extrapyramidal reactions following treatment with antidepressants: Results of the AMSP multinational drug surveillance programme.

Objectives: Extrapyramidal symptoms (EPS) are a common adverse effect of antipsychotics. However, there are case reports describing EPS following treatment with antidepressants. It is not fully understood how antidepressants cause EPS, but a serotonergic input to dopaminergic pathways is a probable mechanism of action.Methods: Data from a multicenter drug-surveillance programme (AMSP, 'drug safety in psychiatry') which systemically documents severe drug reactions during psychiatric inpatient admissions, were reviewed to assess for EPS associated with antidepressant treatment. We identified 15 such cases, which were studied to detect similarities and to characterise risk factors.Results: We report on 15 patients with EPS following antidepressant-therapy between 1994 and 2016. EPS frequently occurred with selective serotonin reuptake inhibitor (SSRI) treatment alone (7/15 cases) or concomitant SSRI treatment (6/15 cases). EPS were most frequent with escitalopram-treatment (5 cases). The most common EPS was atypical dyskinesia (6/15 cases) followed by akathisia (4/15 cases). The mean age of onset for EPS was 54.93 years (SD 17.9). EPS occurred at any dosage and equally often in men and women.Conclusions: Our results highlight the possibility of EPS as an important, although uncommon, adverse effect of antidepressants. Clinicians should beware of this adverse effect and monitor early warning signs carefully.

The Gut Microbiome and Mental Health: What Should We Tell Our Patients?: Le microbiote Intestinal et la Santé Mentale : que Devrions-Nous dire à nos Patients?

The gut microbiome as a potential therapeutic target for mental illness is a hot topic in psychiatry. Trillions of bacteria reside in the human gut and have been shown to play a crucial role in gut-brain communication through an influence on neural, immune, and endocrine pathways. Patients with various psychiatric disorders including depression, bipolar disorder, schizophrenia, and autism spectrum disorder have been shown to have significant differences in the composition of their gut microbiome. Enhancing beneficial bacteria in the gut, for example, through the use of probiotics, prebiotics, or dietary change, has the potential to improve mood and reduce anxiety in both healthy people and patient groups. Much attention is being given to this subject in the general media, and patients are becoming increasingly interested in the potential to treat mental illness with microbiome-based therapies. It is imperative that those working with people with mental illness are aware of the rationale and current evidence base for such treatment strategies. In this review, we provide an overview of the gut microbiome, what it is, and what it does in relation to gut-brain communication and psychological function. We describe the fundamental principles and basic techniques used in microbiome-gut-brain axis research in an accessible way for a clinician audience. We summarize the current evidence in relation to microbiome-based strategies for various psychiatric disorders and provide some practical advice that can be given to patients seeking to try a probiotic for mental health benefit.

From isoniazid to psychobiotics: the gut microbiome as a new antidepressant target.

An awareness of the importance of the gut-brain axis in psychiatric disorders such as depression is increasing. The gut microbiome is a key component of this axis. Gut bacteria can communicate with the brain through a variety of pathways including the hypothalamic-pituitary-adrenal axis, immune modulation, tryptophan metabolism and the production of various neuroactive compounds. Patients with depression, and other mood and anxiety disorders, show distinct compositional changes in their gut bacteria profile, raising the question about a possible aetiological role for the microbiome in these disorders. Evidence is emerging that the gut microbiome may represent a new potential antidepressant target and the term 'psychobiotic' has been coined to describe bacteria which confer mental health benefits. Gut bacteria are easily accessible and can be altered in a variety of ways including through the use of probiotics, prebiotics and dietary change. Psychobiotics containing various Lactobacillus and Bifidobacterium species have demonstrated the ability to improve mood, reduce anxiety and enhance cognitive function in both healthy populations and patient groups. This article provides an overview of the identification and development of antidepressant psychobiotics, from the preclinical evidence in the laboratory to the more recent encouraging results from human trials.

Man and the Microbiome: A New Theory of Everything?

The gut microbiome is implicated in the pathophysiology of a wide range of psychological disorders. Preclinical studies have provided us with key insights into the mechanisms by which the microbiome influences bidirectional gut-brain communication. There are many signaling pathways involved, including the hypothalamic-pituitary-adrenal axis, immune modulation, tryptophan and serotonin metabolism, bile acid transformation, microbial production of neuroactive compounds, and regulation of the endocannabinoid system. The complex and widespread influence of the microbiome on many physiological and psychological processes has generated a keen interest in its therapeutic potential for depression, anxiety, autism, and other psychiatric disorders. It has been shown that the microbiome composition of people suffering with such conditions differs significantly from that of healthy controls, and although the area is in its infancy, interventional studies that alter a person's microbiome through the use of probiotics, prebiotics, or dietary change can alleviate psychopathological symptoms.

Outcomes of Renal Transplantation in Patients With Bipolar Affective Disorder and Schizophrenia: A National Retrospective Cohort Study.

BACKGROUND: Patients with severe psychiatric disorders such as schizophrenia and bipolar affective disorder (BPAD) have in the past been excluded from organ transplantation programs based on their psychiatric illness. However, there is little data on the outcomes of renal transplantation in these patients and little evidence to support such exclusion. METHODS: We reviewed the database of the Irish National Renal Transplant Programme and identified all patients with a history of BPAD or schizophrenia who had received a transplant over a 28-year period. Data were collected for the following outcomes: patient survival, graft survival, graft function, length of hospitalization for transplantation, and frequency of acute rejection episodes. The control group was the general transplant group, that is, all patients without these psychiatric disorders and who had received a renal transplant during the relevant time period. RESULTS: Between January 1, 1986, and December 31, 2013, 3000 renal transplants were performed at our center. Of the transplant recipients, 0.5% (n = 15) had a diagnosis of BPAD and 0.2% (n = 6) had schizophrenia. No significant differences were found between the BPAD or schizophrenia group and the general renal transplant group in relation to patient survival, graft survival, and graft function. In addition, length of hospital admission for transplantation and frequency of acute rejection episodes were comparable among the 3 groups. CONCLUSIONS: Although consideration of psychiatric comorbidity is an important part of pretransplant assessment and selection, patients should not be discriminated against based on a diagnosis of BPAD or schizophrenia as there is no evidence that this negatively affects transplant outcomes.