Lithium effect on temperature rhythm in psychiatric patients.

The diurnal rhythm of oral temperature was studied in 55 lithium treated patients, 51 other psychiatric patients, and 58 healthy subjects. The lithium treated patients had a higher temperature than the normal controls during the 24-hour period and their temperature maximum was shifted towards an earlier time. When the lithium intake was postponed for 12 hours, temperature temporarily decreased to control values, but returned to the higher level after the lithium dose. The temperature results are discussed in relation to lithium induced changes in electrolyte metabolism.