Higher serotonin transporter availability in early-onset obsessive-compulsive disorder patients undergoing escitalopram treatment: A [11 C]DASB PET study.

These findings indicate that the earlier the age of onset of OCD, the less serotonergic pathology there is and that this difference remains even after long-term serotonin reuptake inhibitor treatment. Clinically, it might suggest that nonserotonergic treatments would be a better option for EOCD patients.