Many common typologies, such as comorbid psychopathology (i.e., depression), antisocial phenotype, or no reactivity to SSRIs [7,58,62], have been found between Tph2−/− mice and type II alcoholics, despite differences in the origin of impaired 5-HT transmission (Tph2 deletion; present study vs. homozygosity for the long (L) allele for 5-HTT gene; [7]). Here, TPH2 is linked to depressive symptom measurement.