Lithium lengthens the circadian periods in the SCN, olfactory bulb, median eminence and substantia nigra with dose and area specific manner.
The effective dose of lithium was much higher than the plasma levels that are required for lengthening the circadian behavior rhythms as well for therapeutic use.
Low dose of lithium did not lengthened the period but enhanced the amplitude of circadian rhythms, which may exert therapeutic effects on BD.