Abstract
Mood disorders have been discussed as being in relation to glial pathology. S100B is a calcium-binding protein, and a marker of glial dysfunctions. Although alterations in the S100B ...expression may play a role in various central nervous system diseases, there are no studies on the potential role of S100B in mood disorders in adolescents and young adults . In a prospective two-year follow-up study, peripheral levels of S100B were investigated in 79 adolescent/young adult patients (aged 14–24 years), diagnosed with mood disorders and compared with 31 healthy control subjects. A comprehensive clinical interview was conducted which focused on clinical symptoms and diagnosis change. The diagnosis was established and verified at each control visit. Serum S100B concentrations were determined. We detected: lower S100B levels in medicated patients, compared with those who were drug-free, and healthy controls; higher S100B levels in a depressed group with a family history of affective disorder; correlations between age and medication status; sex-dependent differences in S100B levels; and lack a of correlation between the severity of depressive or hypo/manic symptoms. The results of our study indicate that S100B might be a trait-dependent rather than a state-dependent marker. Due to the lack of such studies in the youth population, further research should be performed. A relatively small sample size, a lack of exact age-matched control group, a high drop-out rate.
Summary Background Lithium is a first-line treatment in bipolar disorder, but individual response is variable. Previous studies have suggested that lithium response is a heritable trait. However, no ...genetic markers of treatment response have been reproducibly identified. Methods Here, we report the results of a genome-wide association study of lithium response in 2563 patients collected by 22 participating sites from the International Consortium on Lithium Genetics (ConLiGen). Data from common single nucleotide polymorphisms (SNPs) were tested for association with categorical and continuous ratings of lithium response. Lithium response was measured using a well established scale (Alda scale). Genotyped SNPs were used to generate data at more than 6 million sites, using standard genomic imputation methods. Traits were regressed against genotype dosage. Results were combined across two batches by meta-analysis. Findings A single locus of four linked SNPs on chromosome 21 met genome-wide significance criteria for association with lithium response (rs79663003, p=1·37 × 10−8 ; rs78015114, p=1·31 × 10−8 ; rs74795342, p=3·31 × 10−9 ; and rs75222709, p=3·50 × 10−9 ). In an independent, prospective study of 73 patients treated with lithium monotherapy for a period of up to 2 years, carriers of the response-associated alleles had a significantly lower rate of relapse than carriers of the alternate alleles (p=0·03268, hazard ratio 3·8, 95% CI 1·1–13·0). Interpretation The response-associated region contains two genes for long, non-coding RNAs (lncRNAs), AL157359.3 and AL157359.4 . LncRNAs are increasingly appreciated as important regulators of gene expression, particularly in the CNS. Confirmed biomarkers of lithium response would constitute an important step forward in the clinical management of bipolar disorder. Further studies are needed to establish the biological context and potential clinical utility of these findings. Funding Deutsche Forschungsgemeinschaft, National Institute of Mental Health Intramural Research Program.
Objectives
In mood disorders, chronic stimulation with stress results in aberrant regulation of the hypothalamic–pituitary–adrenal (HPA) axis. Lithium was shown to influence HPA axis function. The ...underlying genetic background as well as environmental context may influence the stress response, and therefore lithium efficacy. The aim of the present study was to analyze if genetic variants located in genes involved in HPA axis regulation affect the response to long‐term lithium treatment in bipolar patients.
Methods
We included 93 patients with bipolar disorder (32 males and 61 females), aged 31–80 years. The patients had been treated with lithium carbonate for at least 5 years. The magnitude of the lithium response was assessed using the Alda scale. Genotyping was performed for 28 polymorphisms in the genes encoding the following proteins involved in HPA axis regulation: corticotropin‐releasing hormone receptor 1 (CRHR1), arginine vasopressin receptor 1B (AVPR1b), FK506 binding protein (FKBP) 5, FKBP4, BCL2‐associated athanogene 1 (BAG1), stress induced phosphoprotein 1 (STIP1), glucocorticoid‐induced transcript 1 (GLCC1), dual specificity phosphatase 1 (DUSP1) serine and arginine rich splicing factor (SRSF) 3, SRSF9, SRSF5, and acid phosphatase 1 (ACP1). Linkage disequilibrium and haplotype analysis were then performed, followed by statistical analysis (Statistica v.12; Stasoft, Krakow, Poland).
Results
We found a correlation between stressful life events at first episode and worse response to lithium (P=.019). In single marker analysis, we observed a significant association between three FKBP5 polymorphisms (rs1360780, rs7748266 and rs9296158), one ACP1 variant (rs300774) and one glucocorticoid‐induced transcript 1 gene (GLCC1) variant (rs37972) and the degree of lithium response. Five out of seven FKBP5 polymorphisms showed strong linkage with one haplotype demonstrating an association with lithium efficacy (P=.008). No relationship was found between the other analyzed polymorphisms and lithium response.
Conclusion
The response to lithium may depend on the variants of genes regulating the HPA axis and stressful life events in bipolar patients.
Bipolar disorder (BD) is a common and highly heritable mental illness and genome-wide association studies (GWAS) have robustly identified the first common genetic variants involved in disease ...aetiology. The data also provide strong evidence for the presence of multiple additional risk loci, each contributing a relatively small effect to BD susceptibility. Large samples are necessary to detect these risk loci. Here we present results from the largest BD GWAS to date by investigating 2.3 million single-nucleotide polymorphisms (SNPs) in a sample of 24,025 patients and controls. We detect 56 genome-wide significant SNPs in five chromosomal regions including previously reported risk loci ANK3, ODZ4 and TRANK1, as well as the risk locus ADCY2 (5p15.31) and a region between MIR2113 and POU3F2 (6q16.1). ADCY2 is a key enzyme in cAMP signalling and our finding provides new insights into the biological mechanisms involved in the development of BD.
Abstract The outcome of treatment with antidepressants varies markedly across people with the same diagnosis. A clinically significant prediction of outcomes could spare the frustration of trial and ...error approach and improve the outcomes of major depressive disorder through individualized treatment selection. It is likely that a combination of multiple predictors is needed to achieve such prediction. We used elastic net regularized regression to optimize prediction of symptom improvement and remission during treatment with escitalopram or nortriptyline and to identify contributing predictors from a range of demographic and clinical variables in 793 adults with major depressive disorder. A combination of demographic and clinical variables, with strong contributions from symptoms of depressed mood, reduced interest, decreased activity, indecisiveness, pessimism and anxiety significantly predicted treatment outcomes, explaining 5–10% of variance in symptom improvement with escitalopram. Similar combinations of variables predicted remission with area under the curve 0.72, explaining approximately 15% of variance (pseudo R2 ) in who achieves remission, with strong contributions from body mass index, appetite, interest-activity symptom dimension and anxious-somatizing depression subtype. Escitalopram-specific outcome prediction was more accurate than generic outcome prediction, and reached effect sizes that were near or above a previously established benchmark for clinical significance. Outcome prediction on the nortriptyline arm did not significantly differ from chance. These results suggest that easily obtained demographic and clinical variables can predict therapeutic response to escitalopram with clinically meaningful accuracy, suggesting a potential for individualized prescription of this antidepressant drug.
Indirect evidence suggests that common genetic variation contributes to individual differences in antidepressant efficacy among individuals with major depressive disorder, but previous studies may ...have been underpowered to detect these effects.
A meta-analysis was performed on data from three genome-wide pharmacogenetic studies (the Genome-Based Therapeutic Drugs for Depression GENDEP project, the Munich Antidepressant Response Signature MARS project, and the Sequenced Treatment Alternatives to Relieve Depression STAR*D study), which included 2,256 individuals of Northern European descent with major depressive disorder, and antidepressant treatment outcomes were prospectively collected. After imputation, 1.2 million single-nucleotide polymorphisms were tested, capturing common variation for association with symptomatic improvement and remission after up to 12 weeks of antidepressant treatment.
No individual association met a genome-wide threshold for statistical significance in the primary analyses. A polygenic score derived from a meta-analysis of GENDEP and MARS participants accounted for up to approximately 1.2% of the variance in outcomes in STAR*D, suggesting a weakly concordant signal distributed over many polymorphisms. An analysis restricted to 1,354 individuals treated with citalopram (STAR*D) or escitalopram (GENDEP) identified an intergenic region on chromosome 5 associated with early improvement after 2 weeks of treatment.
Despite increased statistical power accorded by meta-analysis, the authors identified no reliable predictors of antidepressant treatment outcome, although they did identify modest, direct evidence that common genetic variation contributes to individual differences in antidepressant response.
The purpose of this study was to identify genetic variants underlying the considerable individual differences in response to antidepressant treatment. The authors performed a genome-wide association ...analysis of improvement of depression severity with two antidepressant drugs.
High-quality Illumina Human610-quad chip genotyping data were available for 706 unrelated participants of European ancestry treated for major depression with escitalopram (N=394) or nortriptyline (N=312) over a 12-week period in the Genome-Based Therapeutic Drugs for Depression (GENDEP) project, a partially randomized open-label pharmacogenetic trial.
Single nucleotide polymorphisms in two intergenic regions containing copy number variants on chromosomes 1 and 10 were associated with the outcome of treatment with escitalopram or nortriptyline at suggestive levels of significance and with a high posterior likelihood of true association. Drug-specific analyses revealed a genome-wide significant association between marker rs2500535 in the uronyl 2-sulphotransferase gene and response to nortriptyline. Response to escitalopram was best predicted by a marker in the interleukin-11 (IL11) gene. A set of 72 a priori-selected candidate genes did not show pharmacogenetic associations above a chance level, but an association with response to escitalopram was detected in the interleukin-6 gene, which is a close homologue of IL11.
While limited statistical power means that a number of true associations may have been missed, these results suggest that efficacy of antidepressants may be predicted by genetic markers other than traditional candidates. Genome-wide studies, if properly replicated, may thus be important steps in the elucidation of the genetic basis of pharmacological response.
Bipolar disorder (BD) is a highly heritable neuropsychiatric disease characterized by recurrent episodes of mania and depression. BD shows substantial clinical and genetic overlap with other ...psychiatric disorders, in particular schizophrenia (SCZ). The genes underlying this etiological overlap remain largely unknown. A recent SCZ genome wide association study (GWAS) by the Psychiatric Genomics Consortium identified 128 independent genome-wide significant single nucleotide polymorphisms (SNPs). The present study investigated whether these SCZ-associated SNPs also contribute to BD development through the performance of association testing in a large BD GWAS dataset (9747 patients, 14278 controls). After re-imputation and correction for sample overlap, 22 of 107 investigated SCZ SNPs showed nominal association with BD. The number of shared SCZ-BD SNPs was significantly higher than expected (p = 1.46x10-8). This provides further evidence that SCZ-associated loci contribute to the development of BD. Two SNPs remained significant after Bonferroni correction. The most strongly associated SNP was located near TRANK1, which is a reported genome-wide significant risk gene for BD. Pathway analyses for all shared SCZ-BD SNPs revealed 25 nominally enriched gene-sets, which showed partial overlap in terms of the underlying genes. The enriched gene-sets included calcium- and glutamate signaling, neuropathic pain signaling in dorsal horn neurons, and calmodulin binding. The present data provide further insights into shared risk loci and disease-associated pathways for BD and SCZ. This may suggest new research directions for the treatment and prevention of these two major psychiatric disorders.
Affective disorders include unipolar disorder (UP) (depression episodes) and bipolar disorder (BP) (depression and mania episodes). Currently, no biological markers are known that can help to ...differentiate these disorders. However, recent studies have suggested that psychiatric disorders can be connected with small, non-coding RNA, like microRNA.
The objective of this study was to analyse the expression level of three microRNAs (miR-499, miR-708, miR-1908) in bipolar and unipolar disorder during depression episodes and after entering the remission state.
The group consisted of adult women only, 17 UP (age: 50±17) and 15 BP (age: 33±13) patients. The expression level of miRNAs was investigated by RT-qPCR with the TaqMan assay.
Our study has shown a lower expression level of miR-499 (p=0.008), miR-708 (p=0.02) and miR-1908 (p=0.004) in depression episodes of the bipolar disorder patients in comparison to remission state.
We have not found similar differences in unipolar disorder and between those types in acute phase of depression and during remission.
Obtained results indicate that miRNAs: miR-499, miR-708 and miR-1908 are the most promising candidates for biomarkers of depression episodes of bipolar disorder.
Abstract Introduction Studies have not given yet a clear answer what is the genetic background of suicidal predisposition. The associations between polymorphisms of the TPH1 and 5-HTTLPR genes and ...violent suicidal behavior was revealed with the least inconsistencies. Method We selected 10 “strong candidate genes” and 35 SNPs, SLC6A4 and ACP1 for replication study. We searched associations between precisely described suicidal phenotype in 825 affective patients and polymorphisms of selected neurobiological pathways genes as well as their interactions that constitute suicidal risk. Results The results confirm the role of TPH1, TPH2, 5HT2A, CRHR1 and ACP1 variants in the risk of suicidal behavior. Limitations In our study we analyzed limited number of candidate genes and only one of them is linked to lithium mechanism of action. We had no data on pharmacological treatment of investigated patients and its relation to the time of suicide attempt. Conclusion Our results indicate that polymorphisms of various signaling pathways are involved in the pathogenesis of suicidal behavior. Non-genetic factors are also involved in the risk of suicidal attempts.
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