Neuroimaging for Depression

Depression can significantly disrupt one's ability to function effectively and efficiently, and the associated performance deficits can seriously jeopardize space mission success. The incidence of serious depression in Earth based analogues of the spaceflight environment has been reported as up to 13% per person per year. Extrapolating from existing reports of depressive episodes during short-duration spaceflight, depression is thus a probable condition in one or more members of a five to seven person crew during a long duration spaceflight (e.g., a 30 month mission to Mars). Mission success can be jeopardized by depression either directly, from the potentially life threatening consequences of lapses in performance, or indirectly, by adding to the workload and stress of other crewmembers. The likelihood and potentially serious consequences of depression during spaceflight explains why the risk of human performance failure due to mood alterations such as depression, anxiety, or other psychiatric and cognitive problems is a Priority 1 risk for all mission types (International Space Station, Moon, Mars). Certain countermeasures are already in place: medications and psychological consultations with ground-crews. However, current in-flight methods to decide whether a countermeasure should be used rely heavily on subjective self-reports. The biological basis of mood disorders suggests neural biomarkers may provide a more objective method for assessing depression. Aim 1 of this proposal, therefore, seeks to identify neural biomarkers sensitive to, and specific for, depression. These measures will be used in evaluating and validating a flight-capable, noninvasive neuroimaging technology (near-infrared spectroscopy and imaging, or NIRS imaging) for its ability to detect biomarkers of depression and its severity. As an initial step towards developing novel select-out criteria, Aim 2 will then evaluate which neural biomarkers appear most promising in detecting an endophenotype that identifies individuals at heightened risk for treatment resistance. Finally, when depression is objectively identified, an appropriate countermeasure needs to be selected. Aim 3 will focus on the ability of brain imaging to help predict the efficacy of Dr. Cartriene's computer based problem solving therapy.