PS, P.S., ps, and other variants may refer to:
Psychology is the science of behavior and mind, including conscious and unconscious phenomena, as well as feeling and thought.
Psoriasis is a long-lasting autoimmune disease characterized by patches of abnormal skin. These skin patches are typically red, itchy, and scaly.
Psychopathy, sometimes considered synonymous with sociopathy, is traditionally defined as a personality disorder characterized by persistent antisocial behavior, impaired empathy and remorse, and bold, disinhibited, and egotistical traits.
Psychosis is an abnormal condition of the mind that results in difficulties telling what is real and what is not.
Pseudoscience consists of statements, beliefs, or practices that are claimed to be both scientific and factual, but are incompatible with the scientific method.
The Book of Psalms ( SAW(L)MZ; Hebrew: תְּהִלִּים or תהילים, 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 a book of the Christian Old Testament.
Psychotherapy is the use of psychological methods, particularly when based on regular personal interaction, to help a person change behavior and overcome problems in desired ways.