Defense Automated Neurobehavioral Assessment Accurately Measures Cognition in Patients Undergoing Electroconvulsive Therapy for Major Depressive Disorder.

OBJECTIVES: The Defense Automated Neurobehavioral Assessment (DANA) is an electronic cognitive test battery. The present study compares DANA to the standard Mini-Mental State Examination (MMSE) in subjects undergoing electroconvulsive therapy for the treatment of major depressive disorder. METHODS: Seventeen inpatient subjects in the Johns Hopkins Hospital Department of Psychiatry were administered longitudinal paired DANA and MMSE tests (7.6 ± 4.1 per patient) from January 10, 2014 to September 26, 2014. Regression analyses were conducted (with or without MMSE scores of 30) to study the impact of the MMSE upper limit, and within-subject regression analyses were conducted to compare MMSE and DANA scores over time. RESULTS: Statistically significant relationships were measured between DANA and MMSE scores. Relationships strengthened when MMSE scores of 30 were omitted from analyses, demonstrating a ceiling effect of the MMSE. Within-subject analyses revealed relationships between MMSE and DANA scores over the duration of the inpatient stay. CONCLUSIONS: Defense Automated Neurobehavioral Assessment is an electronic, mobile, repeatable, sensitive, and valid method of measuring cognition over time in depressed patients undergoing electroconvulsive therapy treatment. Automation of the DANA allows for more frequent cognitive testing in a busy clinical setting and enhances cognitive assessment sensitivity with a timed component to each test.

Seedling responses to water pulses in shrubs with contrasting histories of grassland encroachment.

Woody plant encroachment into grasslands has occurred worldwide, but it is unclear why some tree and shrub species have been markedly more successful than others. For example, Prosopis velutina has proliferated in many grasslands of the Sonoran Desert in North America over the past century, while other shrub species with similar growth form and life history, such as Acacia greggii, have not. We conducted a glasshouse experiment to assess whether differences in early seedling development could help explain why one species and not the other came to dominate many Sonoran Desert grasslands. We established eight watering treatments mimicking a range of natural precipitation patterns and harvested seedlings 16 or 17 days after germination. A. greggii had nearly 7 times more seed mass than P. velutina, but P. velutina emerged earlier (by 3.0±0.3 d) and grew faster (by 8.7±0.5 mg d⁻¹). Shoot mass at harvest was higher in A. greggii (99±6 mg seedling⁻¹) than in P. velutina (74±2 mg seedling⁻¹), but there was no significant difference in root mass (54±3 and 49±2 mg seedling⁻¹, respectively). Taproot elongation was differentially sensitive to water supply: under the highest initial watering pulse, taproots were 52±19 mm longer in P. velutina than in A. greggii. Enhanced taproot elongation under favorable rainfall conditions could give nascent P. velutina seedlings growth and survivorship advantages by helping reduce competition with grasses and maintain contact with soil water during drought. Conversely, A. greggii's greater investment in mass per seed appeared to provide little return in early seedling growth. We suggest that such differences in recruitment traits and their sensitivities to environmental conditions may help explain ecological differences between species that are highly similar as adults and help identify pivotal drivers of shrub encroachment into grasslands.