The cross-cultural and transdiagnostic nature of unwanted mental intrusions

Background/Objective: Unwanted mental intrusions (UMIs), typically discussed in relation to Obsessive-Compulsive Disorder (OCD), are highly prevalent, regardless of the specific nationality, religion, and/or cultural context. Studies have also shown that UMIs related to Body Dysmorphic Disorder (BDD), Illness anxiety/Hypochondriasis (IA-H), and Eating Disorders (EDs) are commonly experienced. However, the influence of culture on these UMIs and their transdiagnostic nature has not been investigated. Method: Participants were 1,473 non-clinical individuals from seven countries in Europe, the Middle-East, and South America. All the subjects completed the Questionnaire of Unpleasant Intrusive Thoughts, which assesses the occurrence and discomfort of four UMI contents related to OCD, BDD, IA-H, and EDs, and symptom questionnaires on the four disorders. Results: Overall, 64% of the total sample reported having experienced the four UMIs. The EDs intrusions were the most frequently experienced, whereas hypochondriacal intrusions were the least frequent but the most disturbing. All the UMIs were significantly related to each other in frequency and disturbance, and all of them were associated with clinical measures of OCD, BDD, IA-H, and EDs. Conclusions: UMIs are a common phenomenon across different cultural contexts and operate transdiagnostically across clinically different disorders.