**4. Discussion**

Whereas it is a common practice to o ffer patients with therapy-resistant OCD treated with DBS a course of CBT after their operation, its e ffectiveness, timing and procedural aspects, such as the preferred way of delivery of such therapy, has hardly been studied. In spite of the fact that the importance of post-operative CBT is stressed by various authors [18–20], only two trials have specifically focussed on CBT added to DBS [13–15].
