1. A method comprising: monitoring at least one physiological parameter of a patient via a medical device that delivers at least one of a movement disorder therapy, psychological disorder therapy, or deep brain stimulation to a patient; determining a value of a metric that is indicative of sleep quality based on the at least one physiological parameter; and automatically controlling delivery of the at least one of the movement disorder therapy, psychological disorder therapy, or deep brain stimulation by the medical device based on the sleep quality metric value.