Abstract It will only be a matter of time before physicians can screen patients for susceptibility to a disease by analyzing their DNA for specific SNP profiles. The study of SNPs associated with dopamine and serotonin systems has a strong interest because of their roles in controlling behaviour and mental status. According to the increasing understanding of the genetic bases of human behaviour, the possible role of SNPs in developmental psychopathologies could be important in forensic studies. Furthermore, the growing interest of forensic researchers in autosomal SNPs is due to the potential advantages in human identity and paternity testing, because of the low rate of mutation and the possibility of analyzing highly degraded samples. The purpose of this study is to report allele frequency data of a Catalonian population sample ( n = 408) from Spain for six SNPs, related to a neurotransmitter pathway genes (ANKK1, DRD2B, HTR1B, TPH1, ADRA2A and OPRM1). No significant deviations from Hardy–Weinberg expectation were found for all SNPs. From a forensic point of view the heterozygosity value, power of discrimination and the a priori chance exclusion value were calculated.