Personal wellness depends on at least seven or more hours of restful sleep per night. There are correlations between insufficient sleep and deterioration of physical and emotional health. There is evidence that short sleep durations have negative physiological and neurobehavioral consequences and can cause dysfunction in the brain. Those dysfunctions may contribute to emotional difficulties and psychiatric conditions, such as psychosis. Housing provides a safe and private place for homeless people to relax and sleep and thus helps prevent the psychosis sleep deprivation can cause. For those already coping with mental illness, housing is an effective treatment for the positive symptom of insomnia. Homeless people must sleep with one eye open as part of their survival. Only housing can break this cycle.