P.S. commonly refers to:
Psoriasis is a long-lasting autoimmune disease characterized by patches of abnormal skin. These skin patches are typically red, dry, itchy, and scaly.
Psychology is the science of behavior and mind. Psychology includes the study of conscious and unconscious phenomena, as well as feeling and thought.
Psychopathy is traditionally a personality disorder characterized by persistent antisocial behavior, impaired empathy and remorse, and bold, disinhibited, and egotistical traits.
Pseudoscience consists of statements, beliefs, or practices that are claimed to be both scientific and factual but are incompatible with the scientific method.
Psychosis is an abnormal condition of the mind that results in difficulties determining what is real and what is not.
The Book of Psalms ( or SAW(L)MZ; Hebrew: תְּהִלִּים, Tehillim, "praises"), commonly referred to simply as Psalms or "the Psalms", is the first book of the Ketuvim ("Writings"), the third section of the Hebrew Bible, and thus a book of the Christian Old Testament.