The Wnt signaling pathway in major depressive disorder: A systematic review of human studies.

Despite uncertainty about the specific molecular mechanisms driving major depressive disorder (MDD), the Wnt signaling pathway stands out as a potentially influential factor in the pathogenesis of MDD. Known for its role in intercellular communication, cell proliferation, and fate, Wnt signaling has been implicated in diverse biological phenomena associated with MDD, spanning neurodevelopmental to neurodegenerative processes. In this systematic review, we summarize the functional differences in protein and gene expression of the Wnt signaling pathway, and targeted genetic association studies, to provide an integrated synthesis of available human data examining Wnt signaling in MDD. Thirty-three studies evaluating protein expression (n = 15), gene expression (n = 9), or genetic associations (n = 9) were included. Only fifteen demonstrated a consistently low overall risk of bias in selection, comparability, and exposure. We found conflicting observations of limited and distinct Wnt signaling components across diverse tissue sources. These data do not demonstrate involvement of Wnt signaling dysregulation in MDD. Given the well-established role of Wnt signaling in antidepressant response, we propose that a more targeted and functional assessment of Wnt signaling is needed to understand its role in depression pathophysiology. Future studies should include more components, assess multiple tissues concurrently, and follow a standardized approach.

Weight changes in adults with major depressive disorder: A systematic review and meta-analysis of prospective studies.

BACKGROUND: Major Depressive Disorder (MDD) and obesity are bidirectionally related, but the amount of weight-gain secondary to MDD is unknown. We aimed to estimate the adjusted effect of MDD on weight-change in prospective studies compared to individuals without MDD. METHODS: Scopus/MEDLINE, PsycInfo, Web of Science and Cochrane were systematically searched for prospective observational studies of participants with a diagnosis of MDD. We included studies that conducted regression analyses on weight-variables. We searched for weight-variables reported at baseline, follow-up, and regression analyses. A meta-analysis of the odds ratios reported in logistic regression models was performed using the generic inverse weight variance method. RESULTS: Eight studies were included with a total of 60,443 subjects; 56.8 % with MDD. Weight-variables included weight, BMI, waist circumference, fat mass, and obesity incidence. In three follow-up reports, weight-variables increased more in participants with MDD and its subphenotypes than in control subjects, except for one MDD subphenotype. Meta-analysis of three eligible studies (n = 21,935) showed a significantly greater likelihood of incident obesity in participants with MDD (OR:1.48, 95%CI 1.03-2.13). MDD subphenotype reports might suggest a greater risk for atypical MDD. LIMITATIONS: Heterogeneity in weight related variables, follow-ups, and regression models; scarcity of follow-up data; and limited studies eligible for meta-analysis. CONCLUSIONS: Despite previous associations between MDD and obesity, current prospective evidence on MDD related weight-change is scarce and heterogeneous. Our findings suggest a need to standardize weight-change assessment in MDD trials. Moreover, careful weight tracking and management should be incorporated in clinical settings. PROSPERO registration CRD42020214427.

Potential pharmacogenomic targets in bipolar disorder: considerations for current testing and the development of decision support tools to individualize treatment selection.

BACKGROUND: Treatment in bipolar disorder (BD) is commonly applied as a multimodal therapy based on decision algorithms that lack an integrative understanding of molecular mechanisms or a biomarker associated clinical outcome measure. Pharmacogenetics/genomics study the individual genetic variation associated with drug response. This selective review of pharmacogenomics and pharmacogenomic testing (PGT) in BD will focus on candidate genes and genome wide association studies of pharmacokinetic drug metabolism and pharmacodynamic drug response/adverse event, and the potential role of decision support tools that incorporate multiple genotype/phenotype drug recommendations. MAIN BODY: We searched PubMed from January 2013 to May 2019, to identify studies reporting on BD and pharmacogenetics, pharmacogenomics and PGT. Studies were selected considering their contribution to the field. We summarize our findings in: targeted candidate genes of pharmacokinetic and pharmacodynamic pathways, genome-wide association studies and, PGT platforms, related to BD treatment. This field has grown from studies of metabolizing enzymes (i.e., pharmacokinetics) and drug transporters (i.e., pharmacodynamics), to untargeted investigations across the entire genome with the potential to merge genomic data with additional biological information. CONCLUSIONS: The complexity of BD genetics and, the heterogeneity in BD drug-related phenotypes, are important considerations for the design and interpretation of BD PGT. The clinical applicability of PGT in psychiatry is in its infancy and is far from reaching the robust impact it has in other medical disciplines. Nonetheless, promising findings are discovered with increasing frequency with remarkable relevance in neuroscience, pharmacology and biology.

Clinical phenotype and genetic risk factors for bipolar disorder with binge eating: an update.

Introduction: Clinical and genetic study of psychiatric conditions has underscored the co-occurrence of complex phenotypes and the need to refine them. Bipolar Disorder (BD) and Binge Eating (BE) behavior are common psychiatric conditions that have high heritability and high co-occurrence, such that at least one quarter of BD patients have BE (BD + BE). Genetic studies of BD alone and of BE alone suggest complex polygenic risk models, with many genetic risk loci yet to be identified. Areas covered: We review studies of the epidemiology of BD+BE, its clinical features (cognitive traits, psychiatric comorbidity, and role of obesity), genomic studies (of BD, eating disorders (ED) defined by BE, and BD + BE), and therapeutic implications of BD + BE. Expert opinion: Subphenotyping of complex psychiatric disorders reduces heterogeneity and increases statistical power and effect size; thus, it enhances our capacity to find missing genetic (and other) risk factors. BD + BE has a severe clinical picture and genetic studies suggests a distinct genetic architecture. Differential therapeutic interventions may be needed for patients with BD + BE compared with BD patients without BE. Recognizing the BD + BE subphenotype is an example of moving towards more precise clinical and genetic entities.

Change in consumption patterns for treatment-seeking patients with alcohol use disorder post-bariatric surgery.

OBJECTIVE: The aim of this study is to describe the clinical phenotype of alcohol use disorder (AUD) treatment-seeking patients with Roux-en-Y Gastric Bypass Surgery (RYGB) history; and to compare it to AUD obese non-RYGB controls. METHODS: Retrospective study of electronic medical records for all patients 30-60years treated at the Mayo Clinic Addiction Treatment Program, between June, 2004 and July, 2012. Comparisons were performed with consumption patterns pre-RYGB and at time of treatment; excluding patients with AUD treatments pre-RYGB. RESULTS: Forty-one out of 823 patients had a RYGB history (4.9%); 122 controls were selected. Compared to controls, the RYGB group had significantly more females [n=29 (70.7%) vs. n=35 (28.7%) p<0.0001]; and met AUD criteria at a significantly earlier age (19.1±0.4 vs. 25.0±1years old, p=0.002). On average, RYGB patients reported resuming alcohol consumption 1.4±0.2years post-surgery, meeting criteria for AUD at 3.1±0.5years and seeking treatment at 5.4±0.3years postoperatively. Pre-surgical drinks per day were significantly fewer compared to post-surgical consumption [2.5±0.4 vs. 8.1±1.3, p=0.009]. Prior to admission, RYGB patients reported fewer drinking days per week vs. controls (4.7±0.3 vs. 5.5±1.8days, p=0.02). Neither RYGB, gender, age nor BMI was associated with differential drinking patterns. CONCLUSION: The results of this study suggest that some patients develop progressive AUD several years following RYGB. This observation has important clinical implications, calling for AUD-preventive measures following RYGB. Further large-scale longitudinal studies are needed to clarify the association between RYGB and AUD onset.