There is no doubt that genetic factors have the potential to predict the therapeutic outcomes of antidepressants in patients with major depressive disorder (MDD). This study investigated the association between genetic variants involved in serotonin signaling and brain-derived neurotrophic factor (BDNF) with the response to escitalopram treatment in patients with MDD. We focused on examining the influence of 5-HTTLPR (ins/del), HTR2A rs9316233, BDNF rs962369, CYP2C19 and CYP2D6 on the clinical response to escitalopram. The patients were recruited from outpatient psychiatric clinics in Košice between 2020 and 2022. Patients received escitalopram for 12 weeks at a fixed dose of 10 mg daily. Clinical assessment was done at baseline and after 4, 8, and 12 weeks using the 21-item Hamilton Depression Rating Scale (HAMD-21). At the end of week 12, 57 (65%) patients were defined as responders to escitalopram treatment, while 31 (35%) patients were non-responders. Genotyping revealed that carriers of the short allele (S) of 5-HTTLPR exhibit a significantly lower therapeutic response to escitalopram measured by HAMD-21 than the long allele (L) carriers (p = 0.01). Adjusting for CYP2C19 and CYP2D6 metabolizer genotypes did not modify the observed relationship between 5-HTTLPR and treatment response. No significant associations were found for HTR2A rs9316233 or BDNF rs962369 variants and the treatment response. These findings underscore the utility of 5-HTTLPR genotyping in guiding escitalopram therapy for MDD patients. Further research with larger cohorts is warranted to validate these results and elucidate additional genetic determinants of antidepressant efficacy.

Since suicide and suicidal behavior are considered highly heritable phenotypes, the identification of genetic markers that can predict suicide risk is a clinically important topic. Several genes studied for possible associations between genetic polymorphisms and suicidal behaviors had mostly inconsistent and contradictory findings. The aim of this case-control study was to evaluate the associations between completed suicide and polymorphisms in genes BDNF (rs6265, rs962369), SLC6A4 (5-HTTLPR), and FTO (rs9939609) in relation to sex and BMI. We genotyped 119 completed suicide victims and 137 control subjects that were age, sex, and ethnicity matched. A significant association with completed suicide was found for BDNF rs962369. This variant could play a role in completed suicide, as individuals with the CC genotype were more often found among suicides than in control subjects. After sex stratification, the association remained significant only in males. A nominally significant association between the gene variant and BMI was observed for BDNF rs962369 under the overdominant model. Heterozygotes with the TC genotype showed a lower average BMI than homozygotes with TT or CC genotypes. FTO polymorphism (rs9939609) did not affect BMI in the group of Slovak suicide completers, but our findings follow an inverse association between BMI and completed suicide.

Evaluation of 5-HTTLPR (insertion/deletion) and BDNF (rs6265) genetic variations in the Slovakian individuals suffering from affective disorders

Schizophrenia spectrum disorders (patients with a diagnosis of schizophrenia, schizotypal, and delusional disorders: F20-F29 according to International Classification of Diseases 10th revision (ICD-10)) are considered highly heritable heterogeneous psychiatric conditions. Their pathophysiology is multifactorial with involved dysregulated serotonergic neurotransmission and synaptic plasticity. The present study aimed to evaluate the association of SLC6A4 (5-HTTLPR), FTO (rs9939609), and BDNF (rs6265, rs962369) polymorphisms with schizophrenia spectrum disorders in Slovak patients. We analyzed the genotypes of 150 patients with schizophrenia, schizotypal, and delusional disorders and compared them with genotypes from 178 healthy volunteers. We have found a marginally protective effect of LS + SS genotypes of 5-HTTLPR variant of the serotonin transporter SLC6A4 gene against the development of schizophrenia spectrum disorders, but the result failed to remain significant after Bonferroni correction. Similarly, we have not proven any significant association between other selected genetic variants and schizophrenia and related disorders. Studies including a higher number of subjects are warranted to reliably confirm the presence or absence of the studied associations.

This study enrolled 291 patients diagnosed with depression and schizophrenia (F32, F33, and F20 according to ICD-10) and 227 ethnicity-matched control subjects. We analyzed the distribution of BDNF rs6265 and BDNF rs962369 genotypes, finding no significant associations between these and schizophrenia. We revealed a significant increase in the risk of single-episode major depression disorder (MDD) for rs962369 minor allele homozygotes (CC vs. TT+TC), an association that persisted after adjusting for age and sex (OR 3.47; 95% CI 1.36–8.85; p = 0.009). Furthermore, rs962369 genotype was significantly associated with an increased risk of recurrent MDD in a log-additive model (OR per C-allele 1.65; 95% CI 1.11–2.45; p = 0.013). A comparative analysis between MDD subtypes and between MDD subtypes and schizophrenia showed no significant differences for BDNF rs6265. Notably, the frequency of minor allele C of BDNF rs962369 varied across subgroups, with the highest frequency in patients with recurrent MDD (0.32) and the lowest in schizophrenia patients (0.20). The presence of genotypes with at least one minor allele C was significantly higher in the recurrent MDD patient group compared to the schizophrenia group. In conclusion, the BDNF rs962369 variant was associated with MDD but not with schizophrenia.