(1) Background: The prevalence of comorbid psychiatric disorders among the patients with mental disorders is higher than general population. The aim of this study was to estimate the prevalence of comorbid psychiatric disorders among a Mexican adolescent sample diagnosed with eating disorders; (2) Methods: Only Mexican adolescents diagnosed with eating disorders were included in the study. The diagnoses were using the DSM-5 criteria. Adolescents with ages between 12 to 17 years were included. The psychiatric comorbidities were evaluated using MINI-kid and QEWP-R. In addition, the z-score values calculated from BMI; (3) Results: The mean age was 14.08±1.7 years old. In our Mexican sample the diagnoses more frequently were bulimia nervosa (55.61%). We found that 89% of the Mexican adolescents with eating disorders had another psychiatric comorbidity. Major depressive disorder (52.40%) and suicide risk (40%) were the most prevalent comorbidity; (4) Conclusions: Our results showed that bulimia nervosa is the most frequently diagnoses in Mexican adolescent and the suicide and major depressive disorder are the principal comorbidities. This emphasizes the importance that clinicians take in-to consideration the presence of psychiatric comorbidities to achieve an integrative treatment for patients with ED.

In order to summarized the polygenic background of psychiatric diseases, polygenic risk scores (PRS) have been developed. Recently, PRS have been use to predict patients with higher comorbidities in psychiatric diseases, like dual diagnosis. PRS are principally derived in analysis of Caucasian and Asian populations, we are not aware of how this PRS could be applied in populations with high admixture. In order to explored this, the present work has the aim to analyzed if previous calculated PRS for psychiatric diseases could predict dual diagnosis in Mexican population, and also, if PRS calculation could be influenced by Mexican Amerindian (MA) global ancestry. We performed PRS calculation, using PRSice, with summary genome-wide association statistics previously published for psychiatric diseases, and also, performed Nagelkerke correlation test in order to established if PRS are correlated with dual diagnosis. We found that dual diagnosis could be predicted by major depressive disorder polygenic risk score. Nevertheless, schizophrenia polygenic risk score is highly correlated with global MA ancestry, independently of the schizophrenia diagnosis. Our results reinforced the notion that PRS calculation could be deviated by the MA global ancestry, nevertheless analysis on larger sample sizes are required in order to clarified this issue.

Eating disorders (ED) are characterized by alterations in eating behavior. The genetic factors shared between ED diagnoses have been underexplored. The present study aimed to perform a genome-wide association study on individuals with disordered eating behaviors in the Mexican population, blood methylation quantitative trait loci (blood-meQTL) analysis, and in silico function prediction by different algorithms. The analysis included a total of 1803 individuals. Genome-wide association study and blood-meQTL analysis were performed by logistic and linear regression. In silico functional variant prediction, phenome-wide, and transcriptome-wide association studies by different algorithms were analyzed. In the genome-wide association study, we identified 44 single-nucleotide polymorphisms (SNP) associated at a nominal value and 7 blood-meQTL at a genome-wide umbral. The SNPs were enriched in genome-wide associations of the metabolic and immunologic domains. In the in silico analysis, the SNP rs10419198 located on an enhancer mark could change the expression of PRR12 on blood, adipocytes, and brain areas that regulate food intake. The present study supports the previous associations of genetic variation in the metabolic domain with ED.