[The lithium test, test of endogenous criteria].

The lithium-test (Li-T) requests hospitalisation of the patient, administration of Li to obtain a plasma/level of at the lust 0, 8 mEq/l, since the third to the eight day. It improve depressions, acute delusions, pseudo-dementias: the field of the lithiodépendent endogenic diseases as to be enlarged. The Li-T may distinguish between this lithiodependence of the other, non-lithiodépendent, in dysthymic psychotic disorders.