Disclosed is the use of a selective phosphodiesterase 7 (PDE7) inhibitory agent in the manufacture of a medicament for treating or reducing the likelihood of an addiction that is a compulsive behaviour associated with a primary impulse-control disorder or an obsessive-compulsive disorder, wherein a subject is determined to be at risk of developing an addiction and is administered an amount of an inhibitor of the PDE7 inhibitory agent effective for the treatment or reduced likelihood of the addiction, and wherein the PDE7 inhibitory agent is a selective PDE7 inhibitor for which the lesser of the IC50 for inhibiting PDE7A activity and the IC50 for inhibiting PDE7B activity is less than one tenth the IC50 that the agent has for inhibiting the activity of all other PDE enzymes from the PDE1-6 and PDE8-11 enzyme families.
