The disclosed apparatus, systems and methods relate to predicting, screening, and monitoring for delirium. Systems and methods may include receiving one or more signals from one or more sensing devices; processing the one or more signals to extract one or more features from the one or more signals; analyzing the one or more features to determine one or more values for each of the one or more features; comparing at least one of the one or more values or a measure based on at least one of the one or more values to a threshold; determining a presence, absence, or likelihood of the subsequent development of delirium for a patient based on the comparison; and outputting an indication of the presence, absence, or likelihood of the subsequent development of delirium for the patient.