Birth defects are structural or functional abnormalities present at birth that cause physical or mental disability. Some may be fatal. Researchers have identified thousands of different birth defects. Currently, birth defects are the leading cause of death for infants during the first year of life.
A mental disorder or mental illness is a psychological pattern, potentially reflected in behavior, that is generally associated with distress or disability, and which is not considered part of normal development of a person’s culture. Mental disorders are generally defined by a combination of how a person feels, acts, thinks or perceives.