1,721,556 research outputs found
Evaluating study designs and treatment outcomes of antidepressant pharmacogenetic clinical trials - Challenges and future perspectives. A critical review
Get PDFSeveral data indicate that the success of pharmacological treatment in major depressive disorder (MDD) is still unsatisfactory. The reasons for the low response and remission rates are multiple and depend on environmental and biological factors intrinsic to the disease and drug treatments. Pharmacogenetic (PG) tests have the potential to increase efficacy predicting outcome and to reduce antidepressant discontinuation due to side effects. Several studies investigated the utility of PG tests for antidepressants in MDD with interesting but contrasting results. To date most of them are observational studies with no comparator group, and few are randomized controlled trials (RCTs). The aim of this review is to provide an evaluation of the state of art on clinical methodologic features of RCTs with PG tests for antidepressant drugs in MDD, offering suggestions and favoring new insights that could be useful in the implementation of future trials. Several limitations concerning study design, generalization of results, duration of trials, patients group studied, and cost-effectiveness ratio were found, and a number of barriers have been noted in the adoption of PG tests into clinical practice. Despite some preliminary positive results, there is the need for larger and longer-term RCT studies, with the goal to capture the real impact of PG tests, also with stratified analysis concerning MDD features in terms of severity and antidepressant treatment failures in different ethnicity cohorts
Evidence of increased risk for major depressive disorder in individuals homozygous for the high-expressing 5-HTTLPR/rs25531 (LA) allele of the serotonin transporter promoter
No full textStacey, David; Cohen-Woods, Sarah; Toben, Catherine; Arolt, Volker; Dannlowski, Udo; Baune, Bernhard T
Impact of selected second and third generation antipsychotics on cognitive dysfunction in schizophrenia-spectrum disorders. Systematic review and network meta-analysis
No full text: Cognitive dysfunction is a core feature of schizophrenia spectrum disorders and a major determinant of functional outcomes. This study aimed to: (a) systematically review randomized controlled trials (RCTs) evaluating the cognitive effects of third-generation antipsychotics (TGAs: brexpiprazole, cariprazine, lumateperone, and lurasidone) and xanomeline-trospium; and (b) perform a network meta-analysis (NMA) including additional second-generation antipsychotics with potential procognitive effects. A systematic literature search identified eligible RCTs, which were combined with trials on aripiprazole, olanzapine, quetiapine, risperidone, and ziprasidone from a previous meta-analysis. A frequentist NMA (random-effects model) was conducted using standardized mean differences (SMDs) in pre-post cognitive scores. Associations between cognitive outcomes, follow-up duration, and SMDs for psychotic symptoms were examined; metaregression controlled for age and psychosis severity. Fourteen RCTs (n = 2464) met the inclusion criteria. Lurasidone (Hedges' g = 0.46) and xanomeline (g = 0.30) outperformed placebo in improving global cognitive performance, whereas quetiapine (g = 0.64) and cariprazine (g = 0.20) had the most favorable impacts on attention. Cognitive SMDs were unrelated to follow-up duration or improvements in psychotic symptoms. Age and baseline psychosis severity did not influence cognitive response. In conclusion, selected second and TGAs, including M1/M4 receptor agonists such as xanomeline, may offer promising treatment options for cognitive dysfunction. Further research should personalize pharmacological strategies based on cognitive profiles
DRD4 48bp multiallelic variants as age-population-specific biomarkers in Attention-Deficit/Hyperactivity Disorder
Get PDFThe identification of biomarkers to support the diagnosis and prediction of treatment response for attention-deficit/hyperactivity disorder (ADHD) is still a challenge. Our previous works highlighted the DRD4 (dopamine receptor D4) as the best potential genetic marker for childhood diagnosis and methylphenidate (MPH) response. Here, we aimed to provide additional evidence on biomarkers for ADHD diagnosis and treatment response, by using more specific approaches such as meta-analytic and bioinformatics tools. Via meta-analytic approaches including over 3000 cases and 16,000 controls, we demonstrated that, among the different variants studied in DRD4 gene, the 48-base pair, Variable Tandem Repeat Polymorphism, VNTR in exon 3 showed an age/population-specificity and an allelic heterogeneity. In particular, the 7R/“long” allele was identified as an ADHD risk factor in European-Caucasian populations (d = 1.31, 95%CI: 1.17–1.47, Z = 4.70/d = 1.36, 95%CI: 1.20–1.55, Z = 4.78, respectively), also, from the results of last meta-analysis, linked to the poor MPH efficacy. The 4R/“short” allele was a protective factor in European-Caucasian and South American populations (d = 0.83, 95%CI: 0.75–0.92, Z = 3.58), and was also associated to positive MPH response. These results refer to children with ADHD. No evidence of such associations was detected for adults with persistent ADHD (data from the last meta-analysis). Moreover, we found evidence that the 4R allele leads to higher receptor expression and increased sensitivity to dopamine, as compared with the 7R allele (d = 1.20, 95%CI: 0.71–1.69, Z = 4.81), and this is consistent with the ADHD protection/susceptibility effects of the respective alleles. Using bioinformatics tools, based on the latest genome-wide association (GWAS) meta-analysis of the Psychiatry Genomic Consortium (PGC), we demonstrated that the 48 bp VNTR is not in Linkage Disequilibrium with the DRD4 SNPs (Single Nucleotide Polymorphisms), which were not found to be associated with ADHD. Moreover, a DRD4 expression down regulation was found in ADHD specific brain regions (Putamen, Z score = −3.02, P = 0.00252). Overall, our results suggest that DRD4 48 bp VNTR variants should be considered as biomarkers to support the diagnosis of ADHD and to predict MPH response, although the accuracy of such a biomarker remains to be further elucidated
Variants in doublecortin- and calmodulin kinase Like 1, a gene up-regulated by BDNF, are associated with memory and general cognitive abilities.
Get PDFBackground: Human memory and general cognitive abilities are complex functions of high heritability and wide variability in the population. The brain-derived neurotrophic factor (BDNF) plays an important role in mammalian memory formation.Methodology / Principal Finding: Based on the identification of genes markedly up-regulated during BDNF-induced synaptic consolidation in the hippocampus, we selected genetic variants that were tested in three independent samples, from Norway and Scotland, of adult individuals examined for cognitive abilities. In all samples, we show that markers in the doublecortin-and calmodulin kinase like 1 (DCLK1) gene, are significantly associated with general cognition (IQ scores) and verbal memory function, resisting multiple testing. DCLK1 is a complex gene with multiple transcripts which vary in expression and function. We show that the short variants are all up-regulated after BDNF treatment in the rat hippocampus, and that they are expressed in the adult human brain (mostly in cortices and hippocampus). We demonstrate that several of the associated variants are located in potential alternative promoter-and cis-regulatory elements of the gene and that they affect BDNF-mediated expression of short DCLK1 transcripts in a reporter system.Conclusion: These data present DCLK1 as a functionally pertinent gene involved in human memory and cognitive functions.</p
Investigation of genetic loci shared between bipolar disorder and risk-taking propensity: potential implications for pharmacological interventions
No full textPublished online: 25 May 2021Patients with bipolar disorder (BD) often show increased risk-taking propensity, which may contribute to poor clinical outcome. While these two phenotypes are genetically correlated, there is scarce knowledge on the shared genetic determinants. Using GWAS datasets on BD (41,917 BD cases and 371,549 controls) and risk-taking (n = 466,571), we dissected shared genetic determinants using conjunctional false discovery rate (conjFDR) and local genetic covariance analysis. We investigated specificity of identified targets using GWAS datasets on schizophrenia (SCZ) and attention-deficit hyperactivity disorder (ADHD). The putative functional role of identified targets was evaluated using different tools and GTEx v. 8. Target druggability was evaluated using DGIdb and enrichment for drug targets with genome for REPositioning drugs (GREP). Among 102 loci shared between BD and risk-taking, 87% showed the same direction of effect. Sixty-two were specifically shared between risk-taking propensity and BD, while the others were also shared between risk-taking propensity and either SCZ or ADHD. By leveraging pleiotropic enrichment, we reported 15 novel and specific loci associated with BD and 22 with risk-taking. Among cross-disorder genes, CACNA1C (a known target of calcium channel blockers) was significantly associated with risk-taking propensity and both BD and SCZ using conjFDR (p = 0.001 for both) as well as local genetic covariance analysis, and predicted to be differentially expressed in the cerebellar hemisphere in an eQTL-informed gene-based analysis (BD, Z = 7.48, p = 3.8E-14; risk-taking: Z = 4.66, p = 1.6E-06). We reported for the first time shared genetic determinants between BD and risk-taking propensity. Further investigation into calcium channel blockers or development of innovative ligands of calcium channels might form the basis for innovative pharmacotherapy in patients with BD with increased risk-taking propensity.Claudia Pisanu, Donatella Congiu, Giovanni Severino, Raffaella Ardau, Caterina Chillotti, Maria Del Zompo ... et al
Genetics of obsessive-compulsive disorder and Tourette disorder
Get PDFObsessive-compulsive disorder (OCD) and Tourette disorder (TD) are neuropsychiatric disorders in which genetic factors play a substantial, and very often shared, role in both disorders. This chapter reviews the current literature on the genetics of OCD and TD, including genetic epidemiology within and across disorders, familiality, candidate gene studies, genome-wide association studies (GWAS), copy number variants (CNVs), imaging genetics, pharmacogenetics, epigenetics, and gene-environment interaction
Biological markers of sex-based differences in major depressive disorder and in antidepressant response
Get PDFMajor depressive disorder (MDD) presents different clinical features in women and men, with women being more affected and responding differently to antidepressant treatment. Specific molecular mechanisms underlying these differences are not well studied and this narrative review aims at providing an overview of the neurobiological features underlying sex-differences in biological systems involved in MDD pathophysiology and response to antidepressant treatment, focusing on human studies. The majority of the reviewed studies were performed through candidate gene approaches, focusing on biological systems involved in MDD pathophysiology, including the stress response, inflammatory and immune, monoaminergic, neurotrophic, gamma-aminobutyric acid and glutamatergic, and oxytocin systems. The influence of the endocrine system and sex-specific hormone effects are also discussed. Genome, epigenome and transcriptome-wide approaches are less frequently performed and most of these studies do not focus on sex-specific alterations, revealing a paucity of omics studies directed to unravel sex-based differences in MDD. Few studies about sex-related differences in antidepressant treatment response have been conducted, mostly involving the inflammatory system, with less evidence on the monoaminergic system and sparse evidence in omics approaches. Our review covers the importance of accounting for sex-differences in research, optimizing patient stratification for a more precise diagnostic and individualized treatment for women and men
Brain aging in major depressive disorder: results from the ENIGMA major depressive disorder working group
No full textAbstract Major depressive disorder (MDD) is associated with an increased risk of brain atrophy, aging-related diseases, and mortality. We examined potential advanced brain aging in adult MDD patients, and whether this process is associated with clinical characteristics in a large multicenter international dataset. We performed a mega-analysis by pooling brain measures derived from T1-weighted MRI scans from 19 samples worldwide. Healthy brain aging was estimated by predicting chronological age (18–75 years) from 7 subcortical volumes, 34 cortical thickness and 34 surface area, lateral ventricles and total intracranial volume measures separately in 952 male and 1236 female controls from the ENIGMA MDD working group. The learned model coefficients were applied to 927 male controls and 986 depressed males, and 1199 female controls and 1689 depressed females to obtain independent unbiased brain-based age predictions. The difference between predicted “brain age” and chronological age was calculated to indicate brain-predicted age difference (brain-PAD). On average, MDD patients showed a higher brain-PAD of +1.08 (SE 0.22) years (Cohen’s d = 0.14, 95% CI: 0.08–0.20) compared with controls. However, this difference did not seem to be driven by specific clinical characteristics (recurrent status, remission status, antidepressant medication use, age of onset, or symptom severity). This highly powered collaborative effort showed subtle patterns of age-related structural brain abnormalities in MDD. Substantial within-group variance and overlap between groups were observed. Longitudinal studies of MDD and somatic health outcomes are needed to further assess the clinical value of these brain-PAD estimates
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