Mediating role of negative beliefs about losing control on symptoms of obsessive-compulsive disorder and orthorexia nervosa among the general population.

Introduction: The co-occurrence of obsessive-compulsive disorder (OCD) and orthorexia nervosa (ON) has been highlighted in numerous previous studies. While the associations between these two conditions are well established, the underlying mechanisms of this relationship remain relatively unexplored. In both conditions the need for control is one of the main factors that plays a key role in maintaining their symptoms. This study aimed to examine the mediating role of negative beliefs about losing control in the relationship between OCD symptoms and ON. Methods: The sample consisted of 268 participants from the Polish general population (76.5% female), aged 18 to 75 years. We used the Polish versions of the Beliefs About Losing Control Inventory, the Obsessive-Compulsive Inventory-Revised and the Eating Habits Questionnaire. Results: The results revealed that more severe OCD symptoms were positively associated with higher levels of negative beliefs about losing control, which in turn predicted ON. OCD symptoms were also positively associated with ON, but only when controlling for the negative beliefs about losing control. Conclusions: The study highlights the significant mediating role of beliefs about losing control in the relationship between OCD symptoms and ON. These findings may enhance our understanding of the underlying mechanisms of both conditions and offer valuable insights for developing more targeted and effective treatment approaches.