First Systematic Theory in Psychiatric Nursing:

Hildegard Peplau, one of the nurse-theorist, published a book on Interpersonal Relations  in Nursing (1952) and gave-the introduction of the first systematic theoretical framework for psychiatric nursing. She focused on the nurse-patient relationship. Her theory has been described as drawing from developmental (Blake,  1980),  interpersonal (Peplau, 1952) and learning (Lego, 1980)  theoriks. 

Peplau  has  defined nursing  as  a  signiJicant, therapeutic, interpersonal, process  that  aims  to  promote  a patientk  health  in  the direction  of  creative, constructive, productive,  personal and  community  living. 

Peplau's  concept and  theory has changed the role of psychiatric nurses to a great  extent.