PROJECT SUMMARY/ABSTRACT Aneurysmal subarachnoid hemorrhage (aSAH) is a form of stroke that strikes relatively young, working-age individuals (typically 30-60 years old; mean age ~50 years old). Cognitive symptoms post-aSAH impair quality of life (QoL). Notably in our preliminary data, cognitive symptoms have gone undiagnosed in ~67% of survivors, as these symptoms are not captured by typical outpatient clinical neurological exams or commonly used general mental status screening modalities. Furthermore, the gold standard of measuring post-aSAH cognitive impairments with neuropsychological testing is frequently unavailable or neglected, and there are no existing guidelines regarding when to trigger such referral. But if these changes are accurately detected and patients are referred, cognitive interventions have shown success in improving outcomes in this population. In short, inadequate detection and phenotyping of cognitive symptoms by clinical neurological exam and/or general mental status screening, in conjunction with non-existent guidelines for in-depth assessment, places patients at risk for cognitively driven poor outcomes and reduced QoL, an outcome that is amenable to intervention. The novel central hypothesis of this proposal is that the Quality of Life in Neurological Disorders (Neuro-QoL), a patient-reported outcome (PRO) battery of questionnaires, can fill this gap in screening for clinical decision-making. Our strong preliminary data demonstrate that the cognitive short form within the Neuro-QoL (NQ-CSF) provides a simple yet critically needed screening tool for use in aSAH survivors; however, this instrument has not yet been tested a) as a benchmark to trigger individual patient referral for in- depth neuropsychological assessment; b) for interpretation in relation to other relevant demographic and clinical information; or c) for interpretation in relation to other Neuro-QoL measures. We respond here to PA- 19-053 and NOT-OD-20-079, and the spirit of PAR-22-231, to propose one highly focused aim: Determine the utility of the Neuro-QoL cognition short form (NQ-CSF) as a benchmark to trigger individual patient referral for in-depth clinical neuropsychological assessment. This project is innovative for applying the Neuro-QoL for clinically meaningful cognitive symptom screening and individualized patient referral post-aSAH. The work will have a significant impact by informing new practice guidelines to provide earlier and more accurate assessment of cognitive symptomatology. Lack of such knowledge reduces QoL for patients affected by aSAH.