RESUMEN
Genetic, social, and environmental conditions contribute to the development of depression, but the pathophysiological mechanisms are still unclear. Data accumulated in recent years provide significant evidence for a direct role of galanin (GAL). This study aimed to investigate the relation between SNPs in the galaninergic system and depressive symptoms in adolescents. A total of112 adolescents aged 10-18years participated in this study. The Children Depression Inventory (CDI) was used to evaluate depressive symptoms. The effects of rs948854 and rs4432027 SNPs, both located within the promoter region of the GAL gene, rs11665337 in the GALR1 receptor, and rs8836 in the GALR2 receptor on depressive symptoms were examined. The results indicated that 30.4% of the participants had depression. We found that girls were significantly more likely to be depressive than boys. Furthermore, rs948854 minor (G) allele was associated with depressive symptoms. Adolescents carrying the GG and AG genotype for the A/G (rs948854) SNP showed higher CDI scores than those carrying homozygous AA. The binomial logistic regression analysis revealed that adolescents carrying the GG genotype at SNP rs948854 had a higher likelihood of being depressive than adolescents carrying the AA or AG genotypes (P=0.033). Moreover, individuals whose mothers had a positive history for depression and who were sedentary were more likely to display depressive symptoms (P=0.013 and P=0.032, respectively). In conclusion, the SNP rs948854 in the GAL gene seems to be involved in the modulation of depressive state, especially in individuals with GG genotype.