摘要:Anxious-depressive attack (ADA) is a symptom complex that comprises sudden intense feelings of anxiety or depression, intrusive rumination of regretful memories or future worries, emotional distress due to painful thoughts, and coping behaviors to manage emotional distress. ADA has been observed trans-diagnostically across various psychiatric disorders. Although the importance of ADA treatment has been indicated, a scale to measure the severity of ADA has not been developed. This study aimed to develop an Anxious-Depressive Attack Severity Scale (ADAS) to measure the severity of ADA symptoms and examine its reliability and validity. A total of 242 outpatients responded to a questionnaire and participated in an interview, which were designed to measure the severity of ADA, depressive, anxiety, anxious depression, and social anxiety symptoms. Based on the diagnostic criteria for ADA, 54 patients were confirmed to have ADA and were included in the main study analyses. The exploratory factor analysis of the ADAS identified a two factor structure: severity of ADA symptoms and ADA frequency and coping behaviors. McDonald’s ωt coefficients were high for the overall scale and the first factor (ωt = .78 and ωt = .83, respectively) but low for the second factor (ωt = .49). The ADAS score was significantly positively correlated with clinical symptoms related to anxiety and depression. The present study demonstrated that the ADAS has sufficient reliability and validity; however, internal consistency was insufficient for the second factor. Overall, the ADAS has potential to be a valuable tool for use in clinical trials of ADA.