Psychosis is a generic psychiatric term for a mental state in which thought and perception are severely impaired. Persons experiencing a psychotic episode may experience hallucinations, hold delusional beliefs (e.g., paranoid delusions), demonstrate personality changes and exhibit disorganized thinking (see thought disorder). This is often accompanied by lack of insight into the unusual or bizarre nature of such behavior, difficulties with social interaction and impairments in carrying out the activities of daily living.