Acute Suicidal Affective Disturbance (ASAD) is a newly proposed diagnostic entity that characterizes rapid onset suicidal intent. This study aims to confirm the factor structure of ASAD among psychiatric inpatients, and to determine the clinical utility of ASAD in predicting suicide attempt status. Overall, 1442 psychiatric inpatients completed a battery of self-report questionnaires assessing symptoms theorized to comprise the ASAD construct. Utilizing these data, a confirmatory factor analysis with a one-factor solution was performed. Regression analyses were employed to determine if the ASAD construct predicted past suicide attempts, and analyses of variance (ANOVAs) were employed to determine if ASAD symptoms differed by the presence and number of past suicide attempts. The one-factor solution indicated good fit: χ(2)(77) = 309.1, p < 0.001, Tucker-Lewis Index (TLI) = 0.96, comparative fit index (CFI) = 0.97, root-mean-square error of approximation (RMSEA) = 0.05. Controlling for depressive disorders and current symptoms, the ASAD construct significantly predicted the presence of a past suicide attempt. Moreover, ASAD differentiated in the expected directions between individuals with a history of multiple suicide attempts, individuals with a single suicide attempt, and individuals with no history of a suicide attempt. Acute Suicidal Affective Disturbance (ASAD) appears to be a unified construct that predicts suicidal behavior and is distinct from an already-defined mood disorder.