Table 4. Sham-controlled studies of DBS in OCD patients.

Study	N	Age, Years (Range)	Female/ Male (N)	Design	Observation (Months)	DBS Target	Results/Conclusions
Mallet et al., 2008 [97]	17	43.05 (29-56)	7/10	Randomized, double-blind, crossover study: two 3-month, and a 1-month washout phases	10	Subthalamic nucleus	Active (second) vs. sham (first) stimulation of the subthalamic nucleus: Y-BOCS scores was significantly lower.
Goodman et al., 2010 [89]	6	36.2 (27-52)	4/2	Randomized, staggered-onset study: either 30- or 60-days (blind) stimulation following surgery	12	Ventral capsule/ ventral striatum, bilaterally	12 months of active stimulation: response in 66.7% (≥35% Y-BOCS improvement or Y-BOCS severity ≤16). Sham stimulation: no improvements.
Denys et al., 2010 [95]	16	42.56 (21-59)	7/9	Three sequential treatment phases: open 8-month treatment phase; double-blind crossover phase with 2-weeks of active or sham stimulation; open 12-month maintenance	21	Nucleus accumbens, bilaterally	Bilateral nucleus accumbens DBS may be an effective and safe treatment. Open phase: 46% Y-BOCS decrease; double-blind, sham-controlled phase: active vs. sham treatment showed 25% Y-BOCS score difference
Baas et al., 2014 [92]	8	39.2 (27-60)*	4/4	Double-blind, crossover study; 2-weeks of active or sham stimulation	1	Ventral internal capsule, bilaterally	Decrease in OC, anxiety, and depressive symptoms.

*Patients were all from Denys et al. [95]. DBS, deep brain stimulation; Y-BOCS, Yale-Brown Obsessive Compulsive Scale.