Pathways to orthorexia nervosa: a case series discussion.

Background: Orthorexia nervosa (ON) has gained increasing interest in the last 2 decades. Although a consensus on the diagnostic boundaries of ON has not yet been reached, there is some evidence for an overlap with eating disorders, obsessive–compulsive disorder, and psychotic disorder. Most of the knowledge about ON has emerged from studies of non-clinical and at-risk populations and is focused on differential diagnosis; therefore, further clinical studies are needed to better outline the ON phenomenon in a real-life setting. Objective: This case series aims at describing clinical cases that developed symptoms suggestive of ON after being diagnosed with a prior psychiatric disorder and then discussing them in light of possible clinical pathways. Methods: Four women consecutively admitted to an outpatient unit for the treatment of eating disorders were diagnosed with ON through a clinical interview, according to Dunn and Bratman’s criteria and self-administered questionnaire assessment (ORTO-15), and were considered to be eligible for this case series study. Psychiatric anamnestic data were collected retrospectively. Results: The anamnesis revealed that all patients were previously diagnosed with a psychiatric disorder (i.e. obsessive–compulsive disorder, bulimia nervosa, illness anxiety disorder, and psychotic disorder) before developing ON. Conclusion: Past literature focused on differential diagnosis between ON and other psychiatric disorders. This is the first description of clinical cases in a real-life setting that started with different psychiatric disorders and later developed symptoms suggestive of ON. These cases have generated a new research question on the possibility that different psychiatric disorders may associate with a later onset of ON. Level of evidence: Level V, descriptive study.