Objective: Clinical and biological correlates of resilience in major depressive disorder are scarce. We aimed to investigate the effect of the Val66Met polymorphism in the BDNF gene on resilience scores in major depressive disorder patients and evaluate the polymorphism’s moderation effect on resilience scores in response to cognitive therapy. Method: A total of 106 major depressive disorder patients were enrolled in this clinical randomized study. The Resilience Scale and the Hamilton Rating Scale for Depression were applied at baseline, post-treatment, and at six months of follow-up. Blood samples were obtained at baseline for molecular analysis. Results: The baseline resilience scores were higher in patients with the Met allele (114.6±17.6) than in those with the Val/Val genotype (104.04±21.05; p = 0.037). Cognitive therapy treatment increased resilience scores (p ≤ 0.001) and decreased depressive symptoms (p ≤ 0.001). In the mixed-effect model, the Val/Val genotype represented a decrease in resilience scores (t218 = -1.98; p = 0.048), and the Val66Met polymorphism interacted with sex to predict an increase in total resilience scores during cognitive treatment (t218 = 2.69; p = 0.008). Conclusion: Our results indicate that cognitive therapy intervention could improve resilience in follow-up, considering that gender and genetic susceptibility are predicted by the Val66Met polymorphism.

Objective: To correlate neurotrophic factors – brain-derived neurotrophic factor (BDNF), glial cell line-derived neurotrophic factor (GDNF), and beta-nerve growth factor (beta-NGF) – and severity of depressive symptoms in patients diagnosed with major depressive disorder (MDD) undergoing cognitive-behavioral therapy (CBT). Methods: In this quasi-experimental study, participants were selected by convenience and received 16 sessions of CBT. The outcomes of interest were severity of depressive symptoms and changes in neurotrophic factor levels after CBT. The differences between variables before and after treatment (deltas) were analyzed. Results: Patients had significant changes in symptom severity after treatment. No significant associations were found between Beck Depression Inventory II (BDI-II) scores and any independent variable. No correlations were observed between BDNF or GDNF levels and BDI scores before or after treatment, although there was a trend toward significant differences in beta-NGF levels. Conclusion: BDNF, beta-NGF, and GDNF were not influenced by the effects of CBT on depressive symptoms.

Objective: To evaluate the serum leptin levels in cannabis smokers. Methods: This was a cross-sectional population-based study of participants between the ages of 18 and 35 years. The data were collected through a self-administered questionnaire covering sociodemographic data and the use of psychoactive substances. Leptin levels were measured using a commercial ELISA kit. Results: Of the 911 participants, 6.7% were identified as cannabis smokers and had significantly lower leptin levels (p = 0.008). When stratified by gender, there was a significant decrease in leptin levels among male smokers (p = 0.039). Conclusion: Cannabis smoking was linked to leptin levels in men, suggesting that the response to biological signals may be different between men and women.

Objective: To evaluate the prevalence of alcohol abuse and/or dependence in a population-based sample of young adults and assess the prevalence of comorbid mood disorders, anxiety, and suicide risk in this population. Methods: This cross-sectional, population-based study enrolled 1,953 young adults aged 18-35 years. The CAGE questionnaire was used to screen for alcohol abuse and/or dependence, with CAGE scores ≥ 2 considered positive. Psychiatric disorders were investigated through the structured Mini International Neuropsychiatric Interview (MINI). Results: Alcohol abuse and/or dependence was identified in 187 (9.60%) individuals (5.10% among women and 15.20% among men). Alcohol abuse and/or dependence were more prevalent among men than women, as well as among those who used tobacco, illicit drugs or presented with anxiety disorder, mood disorder, and suicide risk. Conclusion: These findings suggest that alcohol abuse and/or dependence are consistently associated with a higher prevalence of psychiatric comorbidities, could be considered important predictors of other psychiatric disorders, and deserve greater public heath attention, pointing to the need for alcohol abuse prevention programs.

Objective: To investigate peripheral levels of interleukin-10 (IL-10) in patients with major depressive disorder (MDD) and bipolar disorder (BD) and evaluate the relationship between IL-10, age of disease onset, and duration of illness. Methods: Case-control study nested in a population-based cohort of 231 individuals (age 18-24 years) living in Pelotas, state of Rio Grande do Sul, Brazil. Participants were screened for psychopathology using the Mini-International Neuropsychiatric Interview (MINI) and the Structured Clinical Interview for DSM-IV (SCID-I). Serum IL-10 was measured using commercially available immunoassay kits. Results: Peripheral levels of IL-10 were not significantly different in individuals with MDD or BD as compared to controls. However, higher IL-10 levels were found in MDD patients with a later disease onset as compared with controls or early-onset patients. In addition, IL-10 levels correlated negatively with illness duration in the MDD group. In the BD group, age of onset and duration of illness did not correlate with IL-10 levels. Conclusion: Higher levels of IL-10 are correlated with late onset of MDD symptoms. Moreover, levels of this cytokine might decrease with disease progression, suggesting that an anti-inflammatory balance may be involved in the onset of depressive symptoms and disease progression in susceptible individuals.