Lee JH, et al. - The difference in serotonin transporter (SERT) availability between medicated early-onset obsessive-compulsive disorder (EOCD) and late-onset obsessive-compulsive disorder (LOCD) was investigated in patients undergoing escitalopram treatment. The authors revealed that the earlier the age of onset of an obsessive-compulsive disorder, the less serotonergic pathology there was. Such difference remained even after long-term serotonin reuptake inhibitor treatment. Clinically, it could suggest that in the case of EOCD patients, nonserotonergic treatments would be a better option.