- Obsessive-compulsive disorder (OCD) is a relatively common psychiatric disorder characterized by recurrent obsessive thoughts and/or compulsive behaviors. It has been shown that OCD patients suffer from deficits in executive control. During Stroop task performance, it was found that cognitive control in healthy participants adjusts adaptively – control is reduced when conflict is less likely. Twenty-four individuals meeting criteria for OCD and 27 controls carried out two blocks of a Stroop task; one with high control (a third of the trials were neutral) and one with low control (75% of the trials were neutral). In the healthy control group, results replicated previous findings showing increased interference and decreased facilitation in the low control condition compared to the high control condition. OCD participants, on the other hand, showed no difference in results between the two blocks. Moreover, in the high control condition, interference was larger and facilitation was smaller compared to healthy controls, indicating less efficient executive control for both the informational and task conflict. We concluded that healthy controls adjust the level of control to changing circumstances whereas OCD patients have difficulties to adaptively make such adjustments. Implications for this novel evidence of deficient executive control of flexibility in OCD patients are discussed.