Exhaustion disorder (ED) was introduced to the Swedish version of the International Classification of Diseases, 10th edition (ICD-10) 2005. Primarily characterized by general fatigue and cognitive deficits, ED has become one of the most common mental health diagnoses in Sweden. Little is still known regarding the discriminative validity of the ED diagnosis and how it relates to other diagnostic constructs. The study aimed to investigate the discriminative validity of ED compared with two similar diagnoses, major depressive disorder (MDD) and adjustment disorder (AD). Using data from a sample of patients with a principal diagnosis of either ED (n = 352), MDD (n = 99), or AD (n = 302), we compared demographic and clinical variables and scores on self-report symptom scales. Results showed that ED patients were of a higher age and had a higher frequency of sickness absence than MDD and AD patients. There was a substantial overlap of symptoms between ED and MDD, only differing on two of nine self-report symptom scales, with ED patients rating lower work ability d = -0.37 and alcohol consumption d = -0.57. Compared with AD patients, ED patients reported more severe symptoms in every symptom domain. Given the prevalent use of ED diagnosis, its diagnostic validity and clinical usefulness merit further attention.© 2024 The Author(s). Scandinavian Journal of Psychology published by Scandinavian Psychological Associations and John Wiley & Sons Ltd.
