Case series: Cariprazine in early-onset schizophrenia.

Introduction: Negative symptoms are part of the clinical manifestations of schizophrenia and their presence is associated with a poorer prognosis, significantly limited vocational opportunities, impaired quality of life and social functioning. In the clinical practice, treatment of negative symptoms in patients with schizophrenia, is a challenge. Cariprazine is a novel partial agonist of D3 and D2 receptors, and shows a high affinity for D3, with good tolerability, good response to schizophrenic symptoms and limited side effects. We present two cases of young patients with predominantly negative symptoms during treatment with an atypical antipsychotic, administered in a stable dose and therapeutic range, and for at least 4 weeks prior to the Cariprazine switch. Methods: Two patients (men aged 21 and 22) with schizophrenia, exhibiting predominantly negative symptoms, are presented. Their diagnosis was based on, DSM-5 criteria (295.10).Patients were treated with Cariprazine at a daily dose of 4.5 mg. They were followed for a period of 18 months and assessed with Positive and Negative Syndrome Scale (PANSS), Global Assessment of Functioning (GAF) and Clinical Global Impression-Severity (CGI-S), at the fourth week of initiation of treatment with Cariprazine, at 6 months, at 12 months and at 18 months. Their mean initial value was 75.5 on PANSS, 4.0 on CGI-S, and 52.5 on GAF. Both patients were treated with stable doses of atypical antipsychotic-Risperidone at a daily dose of 4,5 mg. Cross-titration to Cariprazine was initiated, from 1.5 mg daily dose up to 4,5 mg daily dose, during a period of 2 weeks. Results: After 18 months of treatment with Cariprazine at a daily dose of 4.5 mg, the following results were reported: mean value was 57.5 on PANSS, 3.0 on CGI-S, and 74.5 on GAF. The overall PANSS mean score decreased by 23.8%, the CGI-S mean score improved by 25% and the mean GAF score increased by 29.5%. The positive PANSS subscale score decreased minimally, from 20 to 16, while for the negative subscale the improvement was 29.8%.Cariprazine was well tolerated by patients and no side effects were observed from it during therapy. Discussion: After 18 months Cariprazine succeeded in improving negative symptoms, global functioning, and global clinical impression. In young schizophrenic patients with a predominance of negative symptoms, the cariprazine may be a successful alternative.

A Complex Combination Therapy for a Complex Disease-Neuroimaging Evidence for the Effect of Music Therapy in Schizophrenia.

Schizophrenia is a disease characterized by clinical polymorphism: a combination of diverse syndromes defined by differences in structure, course and outcome. The etiology and pathogenesis of this mental disorder is still not completely understood, in spite of the achievements in the fields of neuroscience, genetics, neuroimaging and others. Different treatment strategies have been developed for patients with schizophrenia, but the search for new pharmacological agents continues with the mission of achieving a more effective control over the disease manifestations (positive and negative symptoms), improvement of the patients' social functioning and quality of life. The accumulated clinical experience has revealed that drug treatment and the inclusion in various rehabilitation programs and social skills training shows promising results in these patients. In recent years a plethora of evidence has been compiled regarding the role of music therapy as a possible alternative in the combination treatment of patients with mental disorders, schizophrenia included. Thus, the purpose of this review is to present the reader with a more detailed and science-based account of the beneficial effect of music therapy on the general wellbeing of patients diagnosed with schizophrenia. To fulfill our goal, we will focus mainly on the evidence provided by modern neuroimaging research.

NGS-based mtDNA Profiling Could Reveal Genetic Alterations in Schizophrenia.

BACKGROUND: Schizophrenia is a complex disease with a putative genetic background. It was hypothesized that impaired mitochondrial function due to genetic alterations in mitochondrial DNA (mtDNA) could contribute to neurological conditions, including mental disorders. The aim of the study was to find out possible pathogenic mutations and/or variants in mtDNA potentially related to schizophrenia development. OBJECTIVE: The study involved 37 patients with paranoid schizophrenia, whose mtDNA profiles were compared to those of 23 healthy controls. METHODS: Patients and controls were assessed using PANSS (Positive and Negative Syndrome Scale) and General Health Questionnaire (GHQ), respectively. The entire mtDNA was sequenced by the NGS platform (MiSeq®, Illumina). Bioinformatics data were processed by mtDNA Variant Processor and Analyser (Illumina), mtDNA-Server, and SPSS-17. RESULTS: A total of 480 mtDNA variants (single nucleotide replacements, point insertions, and deletions) were found. The polymorphic variant m.1811A>G (MT-RNR2) showed the highest frequency in schizophrenia (24.3%), as compared to the controls (4.3%) (p=0.07). Increased frequency was also found mainly in polymorphisms, belonging to complex 1 genes: MT-ND4 (11251G and 11467G), MT-ND3 (10398G), MT-ND1 (4216С), and MT-ND5 (12611G and 13708А), some of which were associated with mitochondrial dysfunction. Two individual mutations were identified in the patients: a pathogenic one - m.11778 A>G (LHON) and a newly identified, potentially pathogenic - m.4115 Т>C (NADH dehydrogenase 1). CONCLUSION: Particular mtDNA variants predominantly in complex I, probably serve as a risk genetic background in schizophrenia. The presence of pathogenic mutations in patients with psychotic manifestations expands the clinical scope of mitochondrial diseases and deserves further investigation.

Assessment and Treatment of Negative Symptoms in Schizophrenia-A Regional Perspective.

Clinicians and researchers consider that there are a variety of symptoms that constitute negative symptoms in schizophrenia, and they may use different definitions for the same symptoms. These differences are also reflected in a variety of negative symptom rating scales. Both research and clinical work are negatively affected by the lack of consensus regarding the symptoms that constitute negative symptoms in schizophrenia. Leading research groups have investigated ways to reduce heterogeneity in the domain of negative symptoms in schizophrenia; however, little attention has been paid to regional differences in the concepts of negative symptoms in schizophrenia. The objective of this review was to collect and summarize information about the assessment and treatment of negative symptoms of schizophrenia in Central and Eastern Europe (CEE). Nineteen experts from 17 countries in CEE participated in this project. The participants collected information about their countries, including the following: (1) the most important publications about negative symptoms in schizophrenia (irrespective of the time of their publication); (2) the most frequently used negative symptom of schizophrenia in clinical practice; (3) definitions of frequently used negative symptoms; and (4) treatment of negative symptoms in schizophrenia. The participating experts/countries most frequently reported the following five negative symptoms: avolition, blunted affect, alogia, asociality, and anhedonia. Several experts also considered other symptoms as belonging to the negative symptom domain, such as a decrease in energy level and changes in personality. The importance of evaluating the long-term course and the relationship between negative symptoms and other symptom domains was also noted. No noticeable differences were reported in the treatment of negative symptoms compared to currently published guidelines and algorithms. The most frequently reported negative symptoms included those defined by the NIMH-MATRICS consensus statement on negative symptoms and recently endorsed in a guidance paper of the European Psychiatric Association. The main differences in the concepts, names, and definitions of primary negative symptoms, especially those related to personality changes, and to the evaluation of the long-term course and relationship between different symptom domains in CEE compared to the current English language literature deserve the attention of psychiatrists and other professionals in this field.

The Dysregulation of microRNAs and the Role of Stress in the Pathogenesis of Mental Disorders.

MicroRNAs are endogenous small non-coding RNAs that regulate gene expression by means of partial complementarity to microRNA binding sites at their target genes. These molecules have emerged as key regulators of almost every biological process including accurate control of neuronal gene expression. The authors discuss the current state of microRNA research, including studies of psychiatric disorders (schizophrenia, autism spectrum disorder and affective disorders). Stress has also been shown to have a critical role in the development of psychiatric disorders, at least partially, through mechanisms related to neural plasticity. Synaptic connections in the brain undergo experience-dependent functional or morphological changes through complex pathways that are not yet fully understood, but for which microRNAs might have a critical role. The focus is on the role that microRNAs play in the development of psychiatric disorders and their potential to serve as biomarkers of disease as well as targets for pharmacological treatment.

Cognitive Impairment and Affective Disorders in Patients With Obstructive Sleep Apnea Syndrome.

Sleep-related breathing disorders could be accompanied by or caused by a variety of medical conditions. They are considered to be a significant medical and social problem. Together with excessive daytime sleepiness, patients with obstructive sleep apnea experience neuropsychological symptoms such as anxiety, attention deficits, cognitive impairment, depressive symptoms and other psychological disturbances leading to social adjustment difficulties. Patients diagnosed with obstructive sleep apnea demonstrate a decline in a wide spectrum of cognitive abilities, including memory, attention, psychomotor speed, executive, verbal and visual-spatial skills. The aim of this study is to investigate the cognitive functioning and affective disorders among patients with obstructive sleep apnea syndrome and to examine the frequency and severity of cases in comparison with a control group consisting of healthy volunteers. Our research has shown that there is a relation between sleep apnea and cognitive impairments and affective changes. This relation can be explained by the direct effect of the syndrome on the patient, where the main connecting factor is the severity and the distribution of excessive daytime sleepiness. Along with treatment of the somatic medical condition, it is extremely important that the patient's mental state is treated as well. Trial Registration: 57/2013, Medical University - Sofia, Bulgaria.

Efficacy of Tianeptine 25-50 mg in Elderly Patients With Recurrent Major Depressive Disorder: An 8-Week Placebo- and Escitalopram-Controlled Study.

OBJECTIVE: The present placebo-controlled study evaluated the efficacy and safety of 8 weeks of treatment with tianeptine 25-50 mg/d in elderly patients suffering from major depressive disorder (MDD) according to DSM-IV-TR. Escitalopram 5-10 mg/d was used as an active comparator. METHODS: Elderly outpatients aged at least 65 years with a primary diagnosis of moderate to severe episode of recurrent MDD were recruited by psychiatrists in 44 clinical centers in 10 countries from October 2013 to January 2016. Patients were randomly assigned to receive tianeptine (n = 105), placebo (n = 107), or escitalopram (n = 99) for 8 weeks. The primary outcome measure was the 17-item Hamilton Depression Rating Scale (HDRS17) total score. RESULTS: Tianeptine improved depressive symptoms, as evaluated by the HDRS17 total score in terms of absolute change from baseline (week 0) to week 8 (placebo-tianeptine difference [SE] of 3.84 [0.85] points, P < .001, using a last-observation-carried-forward approach) and response to treatment (tianeptine: 46.7%; placebo: 34.0%, estimate [SE] = 12.70% [6.70], P = .06). A sensitivity analysis using a mixed model for repeated measures confirmed the main results on HDRS total s​core. The placebo-tianeptine difference (SE) was 0.66 (0.15) for Clinical Global Impressions-Severity of Illness (95% CI, 0.37 to 0.96; P < .001) and 0.57 (0.14) for Clinical Global Impressions- Improvement (95% CI, 0.30 to 0.83; P < .001). Positive results were also obtained with the active control escitalopram (HDRS17 total score placebo-escitalopram difference of 4.09 ± 0.86 points, P < .001), therefore validating the sensitivity of the studied population. Tianeptine was well tolerated, with only minimal differences in tolerability from placebo. CONCLUSIONS: The present study provides robust evidence that an 8-week treatment period with tianeptine 25-50 mg is efficacious and well tolerated in depressed patients aged 65 years or older. TRIAL REGISTRATION: EudraCT identifier: 2012-005612-26​.

A study of TNF-α, TGF-ß, IL-10, IL-6, and IFN-γ gene polymorphisms in patients with depression.

In the last decade it was found that functional polymorphisms in the promoter and/or coding regions of regulatory genes are likely to pre-determine the phenotype manifestation of a certain cytokine profile, and thus could be used as disease-associated markers. Having in mind the hypothesis of impaired cytokine regulation in depressive disorder, as well as the diverse population-dependent results for cytokine polymorphisms, we investigated the relation between the cytokine gene polymorphisms of key pro- and anti-inflammatory cytokines (TNF-α, TGF-ß, IL-10, IL-6, IFN-γ) and susceptibility as well as clinical course of depression in Bulgarians. The study included 80 patients with depression (50 women and 30 men) and 50 healthy controls. Simultaneous analysis of eight polymorphic positions in the cytokine genes listed was performed by PCR-SSP method. The results revealed significant predominance of TGF-ß TT (+869) genotype (previously described as predicting low expression activity of TGF-ß) in patients (41.3%) compared to healthy subjects (21.2%) (p=0.05, OR=2.62). Furthermore T/T G/C combined genotype (+869, +915) in the same gene was negatively associated with disease recurrence. Additionally we found that certain IL-10 genotypes associated with low gene expression seemed to shape moderate disease manifestation. In conclusion our results mainly demonstrated prevalence of a low-expression TGF-ß1 profile in the patients. Thus, although in an indirect way, we supported the hypothesis of impaired immunosuppression by means of Th3 regulation in major depressive disorders.

A Flexible-Dose Study of Paliperidone ER in Patients With Nonacute Schizophrenia Previously Treated Unsuccessfully With Oral Olanzapine.

OBJECTIVE: The goal of this study was to explore the tolerability, safety, and treatment response of switching from oral olanzapine to paliperidone extended release (ER). METHODS: Adult patients with nonacute schizophrenia who had been treated unsuccessfully with oral olanzapine were switched to flexible doses of paliperidone ER (3 to 12 mg/d). The primary efficacy outcome was a ≥ 20% improvement in Positive and Negative Syndrome Scale (PANSS) total scores from baseline to endpoint for patients who switched medications because of lack of efficacy with olanzapine and noninferiority versus previous olanzapine treatment (mean endpoint change in PANSS total scores vs. baseline of ≤ 5 points) for patients who switched for reasons other than lack of efficacy. Safety and tolerability were assessed by monitoring adverse events, extrapyramidal symptoms, and weight change. RESULTS: Of 396 patients, 65.2% were men, mean age was 40.0 ± 12.0 years, and 75.5% had paranoid schizophrenia. Among the patients whose main reason for switching was lack of efficacy, an improvement in the PANSS total score of ≥ 20% occurred in 57.4% of patients. Noninferiority was confirmed for each subgroup of patients whose main reason for switching was something other than lack of efficacy. Paliperidone ER was generally well tolerated. Extrapyramidal symptoms as measured by total Extrapyramidal Symptom Rating Scale scores showed statistically significant and clinically relevant improvements at endpoint, the average weight decreased by 0.8 ± 5.2 kg at endpoint, and a clinically relevant weight gain of ≥ 7% occurred in 8.0% of patients. CONCLUSION: Paliperidone ER flexibly-dosed over 6 months was well tolerated and associated with a meaningful clinical response in patients with nonacute schizophrenia who had previously been unsuccessfully treated with oral olanzapine.

De novo CNVs in bipolar affective disorder and schizophrenia.

An increased rate of de novo copy number variants (CNVs) has been found in schizophrenia (SZ), autism and developmental delay. An increased rate has also been reported in bipolar affective disorder (BD). Here, in a larger BD sample, we aimed to replicate these findings and compare de novo CNVs between SZ and BD. We used Illumina microarrays to genotype 368 BD probands, 76 SZ probands and all their parents. Copy number variants were called by PennCNV and filtered for frequency (<1%) and size (>10 kb). Putative de novo CNVs were validated with the z-score algorithm, manual inspection of log R ratios (LRR) and qPCR probes. We found 15 de novo CNVs in BD (4.1% rate) and 6 in SZ (7.9% rate). Combining results with previous studies and using a cut-off of >100 kb, the rate of de novo CNVs in BD was intermediate between controls and SZ: 1.5% in controls, 2.2% in BD and 4.3% in SZ. Only the differences between SZ and BD and SZ and controls were significant. The median size of de novo CNVs in BD (448 kb) was also intermediate between SZ (613 kb) and controls (338 kb), but only the comparison between SZ and controls was significant. Only one de novo CNV in BD was in a confirmed SZ locus (16p11.2). Sporadic or early onset cases were not more likely to have de novo CNVs. We conclude that de novo CNVs play a smaller role in BD compared with SZ. Patients with a positive family history can also harbour de novo mutations.

De novo mutations in schizophrenia implicate synaptic networks.

Inherited alleles account for most of the genetic risk for schizophrenia. However, new (de novo) mutations, in the form of large chromosomal copy number changes, occur in a small fraction of cases and disproportionally disrupt genes encoding postsynaptic proteins. Here we show that small de novo mutations, affecting one or a few nucleotides, are overrepresented among glutamatergic postsynaptic proteins comprising activity-regulated cytoskeleton-associated protein (ARC) and N-methyl-d-aspartate receptor (NMDAR) complexes. Mutations are additionally enriched in proteins that interact with these complexes to modulate synaptic strength, namely proteins regulating actin filament dynamics and those whose messenger RNAs are targets of fragile X mental retardation protein (FMRP). Genes affected by mutations in schizophrenia overlap those mutated in autism and intellectual disability, as do mutation-enriched synaptic pathways. Aligning our findings with a parallel case-control study, we demonstrate reproducible insights into aetiological mechanisms for schizophrenia and reveal pathophysiology shared with other neurodevelopmental disorders.

Predictors of medication non-adherence in Bulgarian outpatients with schizophrenia.

The purpose of this study is to assess the adherence status and to identify the risk factors for medication non-adherence in Bulgarian outpatients with schizophrenia. Variables with possible impact on adherence behaviour were assessed via a set of pre-determined clinical interviews and self-rating scales in a total of 226 patients with schizophrenia. As non-adherent were classified 55.8% of the participants. Differences between adherent and non-adherent patients were identified. A multiple regression analysis revealed three variables predictive for the medication adherence--attitudes toward medication, severity of positive symptoms and the ability to recognize psychotic symptoms. Interventions focusing on the identified predictive variables might be useful when aiming at improvement of medication adherence and outcome in schizophrenia.

Whole genome methylation analyses of schizophrenia patients before and after treatment.

The aetiology of schizophrenia is still unknown but it involves both heritable and non-heritable factors. DNA methylation is an inheritable epigenetic modification that stably alters gene expression. It takes part in the regulation of neurodevelopment and may be a contributing factor to the pathogenesis of brain diseases. It was found that many of the antipsychotic drugs may lead to epigenetic modifications. We have performed 42 high-resolution genome-wide methylation array analyses to determine the methylation status of 27,627 CpG islands. Differentially methylated regions were studied with samples from 20 Bulgarian individuals divided in four groups according to their gender (12 males/8 females) and their treatment response (6 in complete/14 in incomplete remission). They were compared to two age and sex matched control pools (110 females in female pool/110 males in male pool) before and after treatment. We found significant differences in the methylation profiles between male schizophrenia patients with complete remission and control male pool before treatment (C16orf70, CST3, DDRGK1, FA2H, FLJ30058, MFSD2B, RFX4, UBE2J1, ZNF311) and male schizophrenia patients with complete remission and control male pool after treatment (AP1S3, C16orf59, KCNK15, LOC146336, MGC16384, XRN2) that potentially could be used as target genes for new therapeutic strategies as well as markers for good treatment response. Our data revealed major differences in methylation profiles between male schizophrenia patients in complete remission before and after treatment and healthy controls which supports the hypothesis that antipsychotic drugs may play a role in epigenetic modifications.

Whole-genome-wide association study in the Bulgarian population reveals HHAT as schizophrenia susceptibility gene.

OBJECTIVE: Schizophrenia, the most common major psychiatric disorder (or group of disorders), entails severe decline of higher functions, principally with alterations in cognitive functioning and reality perception. Both genetic and environmental factors are involved in its pathogenesis; however, its genetic background still needs to be clarified. The objective of the study was to reveal genetic markers associated with schizophrenia in the Bulgarian population. METHODS: We have conducted a genome-wide association study using 554 496 single nucleotide polymorphisms (SNPs) in 188 affected and 376 unaffected Bulgarian individuals. Subsequently, the 100 candidate SNPs that revealed the smallest P-values were further evaluated in an additional set of 99 case and 328 control samples. RESULTS: We found a significant association between schizophrenia and the intronic SNP rs7527939 in the HHAT gene (P-value of 6.49×10 with an odds ratio of 2.63, 95% confidence interval of 1.89-3.66). We also genotyped additional SNPs within a 58-kb linkage disequilibrium block surrounding the landmark SNP. CONCLUSION: We suggest rs7527939 to be the strongest indicator of susceptibility to schizophrenia in the Bulgarian population within the HHAT locus.

Descriptive analyses of the aripiprazole arm in the risperidone long-acting injectable versus quetiapine relapse prevention trial (ConstaTRE).

A recent randomized, open-label, relapse prevention trial (ConstaTRE) compared outcomes with risperidone long-acting injectable (RLAI) versus the oral atypical antipsychotic quetiapine. This study also included a small descriptive arm in which patients could also be randomized to aripiprazole. Results of this exploratory analysis are described here. Clinically stable adults with schizophrenia or schizoaffective disorder previously treated with oral risperidone, olanzapine, or an oral conventional antipsychotic were randomized to RLAI or aripiprazole. Efficacy and tolerability were monitored for up to 24 months. A total of 45 patients were treated with aripiprazole (10-30 mg/day) and 329 patients with RLAI (25-50 mg i.m. every 2 weeks). Relapse occurred in 27.3% (95% CI: 15.0-42.8%) of aripiprazole-treated and 16.5% (95% CI: 12.7-21.0%) of RLAI-treated patients. Kaplan-Meier estimates of mean (standard error) relapse-free period were 313.7 (20.4) days for aripiprazole and 607.1 (11.4) days for RLAI patients. Remission was achieved by 34.1% (95% CI: 20.5-49.9%) of aripiprazole and 51.1% (95% CI: 45.5-56.6%) of RLAI patients. Clinical global impression-change was improved ("minimally improved" to "very much improved") in 26.4% with RLAI and 15.9% with aripiprazole patients. Tolerability was generally good for both treatment groups. Weight gain (7.0% with RLAI vs. 4.4% with aripiprazole), extrapyramidal adverse events (AEs) (10.3% vs. 4.4%), and potentially prolactin-related AEs (4.6% vs. 0%) were more common with RLAI treatment, and gastrointestinal disorders were more common in aripiprazole-treated patients (22.2% vs. 6.1%). Time-to-relapse in stable patients with schizophrenia or schizoaffective disorder was numerically longer in RLAI-treated patients than in aripiprazole-treated patients although not statistically significant. Both treatments were generally well tolerated.

Attitudes toward antipsychotic medication, insight and psychopathology in outpatients with schizophrenia.

OBJECTIVE: Attitude toward antipsychotic medication is considered as one of the main predictors for medication adherence in schizophrenia. The present non-interventional cross-sectional study aims to explore the associations between attitudes toward antipsychotic medication, insight and other clinical variables in outpatients with schizophrenia. METHOD: Attitudes toward antipsychotic medication, clinical and social variables, sociodemographic and illness-related characteristics were assessed via a set of semi-structured clinical interviews and self-rating scales in a total of 226 patients with schizophrenia on a long-term antipsychotic treatment in community based settings. The associations between attitudes toward medication and severity of psychopathology, insight and medication side effects were examined. RESULTS: The greater hospitalization rate in the previous year was associated with more severe psychopathology at the time of the study, more pronounced side effects of the therapy and lack of insight. The lack of insight, the presence of more severe negative and depressive symptoms and disease duration less than 5 years correlated significantly with negative attitudes toward antipsychotic medication. The severity of medication side effects was not associated with the drug attitudes. CONCLUSION: Psychoeducational and psychotherapeutical interventions, along with pharmacotherapy, can be beneficial in forming positive attitudes toward medication and improving medication adherence in schizophrenia, especially in patients with a short duration of the disease.

Obstructive sleep apnea syndrome and depressive symptoms.

A strong body of evidence has emerged over the recent years suggesting a relationship between obstructive sleep apnea (OSA) and depressive symptoms. The frequent co-occurrence of the two conditions makes it necessary that their co-morbidity and the pathogenetic relations between them should be studied in detail. Most of the studies to date have found a significant correlation between depressive symptoms and OSA. The basic pathogenetic mechanisms involved are disturbed neurotransmission, synaptic remodeling and neuronal death (neuroplasticity). Further longitudinal studies are needed to completely elucidate the OSA-depression relationship. Better knowledge of the problem may significantly improve diagnostics and therapeutical options in that group of patients.

Case-control association study of 65 candidate genes revealed a possible association of a SNP of HTR5A to be a factor susceptible to bipolar disease in Bulgarian population.

BACKGROUND: Bipolar affective disorder (BAD) is a psychiatric illness characterized by episodes of mania and depression. Although the etiology is not clear, epidemiological studies suggest it is a result of an interaction of genetic and environmental factors. Despite of enormous efforts and abundant studies conducted, none has yet been identified definitively a gene susceptible to bipolar disorder. METHODS: Ninety-four Bulgarian patients diagnosed with bipolar disorder and 184 Bulgarian healthy individuals, were used for genotyping of 191 single nucleotide polymorphisms (SNPs) by TaqMan and/or Invader assays. Seventeen SNPs that revealed P value less than 0.05 in the first screening were genotyped using an additional independent set of samples, consisting of 78 BAD cases and 372 controls. RESULTS: After applying the Bonferonni correction on genotyping results of 172 cases and 556 controls, only one SNP, rs1800883, in the HTR5A gene revealed a significant level of P value (P=0.000097; odds ratio=1.80 (95%CI, 1.27-2.54); corrected P=0.017). CONCLUSIONS: Our findings suggest that HTR5A gene could play an important role in the pathogenesis of bipolar disorder in our population. However these findings should be viewed with caution and replication studies in other populations are necessary in support of these findings.