Physical medicine, and in particular physical and occupational therapy, have a well established role in the treatment of psychiatric disorders. We can trace the origin of physical treatment of mental disease to our earliest records. The methods used then were certainly physical but perhaps were not strictly medical, as they included immersion, manipulation and beating to drive out evil spirits. Hydrotherapeutic measures can boast of a long historic background and still comprise an essential feature of treatment of the psychotic patient in all adequate hospitals.
The rationale for the use of water in various forms is frequently based on empiricism but has stood the test of many years of clinical experience with some objective benefit to the patient. The two measures most universally employed are the continuous tub at neutral temperatures and the cold and neutral wet sheet pack. These forms of treatment have been found to be most advantageous
WATKINS AL, FINESINGER JE. PSYCHIATRIC ASPECTS OF PHYSICAL MEDICINE. JAMA. 1947;135(16):1050-1053. doi:10.1001/jama.1947.02890160008003