“Independent study comparing the validity and sensitivity of DANA and the standard Mini-Mental State Examination (MMSE) in measuring cognition over time in subjects with major depressive disorder (MDD) undergoing electroconvulsive therapy (ECT) treatment. Objectives: The MMSE is the most commonly used method of tracking cognitive function in ECT studies, but it is not a timed test, and it has a maximum score of 30, creating a ceiling effect. DANA provides results that are timed to the millisecond and it measures cognition using accuracy (number correct), reaction time, and a combined accuracy and reaction time throughput (i.e., no maximum score). The purpose of this study was to measure the relationship between DANA and MMSE scores and measure cognitive changes over time using DANA and the MMSE. Methods: 17 patients diagnosed with MDD (who failed to respond to standard pharmacological intervention and psychotherapy and were therefore receiving ECT treatment at the Johns Hopkins Hospital Department of Psychiatry) were administered paired DANA and MMSE tests at baseline and throughout their 8 month inpatient stay. 2 separate analyses were then performed: one to validate DANA against MMSE data, and one to measure how the MMSE ceiling effect affected such validation. All cognitive data collected in the study were included in the first analyses to validate DANA when measured against MMSE. MMSE scores of 30 (along with their corresponding DANA scores) were excluded in the second set of analyses to determine if the relationship between DANA and MMSE scores was strengthened when the MMSE ceiling effect was removed. Results: Statistically significant relationships were measured between DANA and MMSE scores pooled from all patients in both analyses. Further, examination of the within-patient DANA and MMSE data over time revealed the following: (1) nearly half of all patients had similar trends in DANA and MMSE scores over time, further validating DANA to the MMSE; (2) some patients experienced declines in both MMSE and DANA scores over time, but at different rates (e.g., MMSE scores did not decline until the very end of the testing period, whereas DANA tests demonstrated a steady, linear performance decline over the entire testing period). The observation that DANA allows for discrete, measurable changes whereas MMSE cannot detect impairment suggests an enhanced sensitivity of the DANA test as compared with MMSE; and (3) a clear MMSE upper limit was detected in the 5 patients who had the maximum MMSE score initially and experienced no change in MMSE scores over time, whereas the DANA scores for such patients went up or down, highlighting the ceiling effect limitation of the MMSE. Sensitivity and Longitudinal Validity of DANA: DANA is a repeatable, sensitive, and valid method of measuring cognition over time in depressed patients undergoing ECT treatment. The timed component of DANA provides an additional and critical dimension to the evaluation of cognitive function, thereby producing a more sensitive overall measurement of cognition as compared with the MMSE and making DANA an appropriate method of measuring changes in cognitive function over time. “