The authors try to determine the incidence of long-term lithium treatments on sleep, appetite and sexual behaviour. The study was conducted in fifty outpatients of both sexes who have been for at least six months on lithium only and whose mood disturbances are stabilized. In two thirds of the cases of this clinical study, lithium seems to have beneficient qualitative and quantitative effects on sleep as opposed to other psychotropic drugs which cause discomforting sleepiness. Lithium seems to influence appetite slightly although it is responsible for the gain in weight in a fourth of the treated outpatients. Half of the subjects consider that lithium modifies their sexuality towards a decrease of the desire without modifying their capacities of realization. In a comparison study conducted with the psychotropic drugs that had been administered before, the repercussions of lithium on sexuality appear thus opposite to those of psychotropic drugs, major tranquilizers and antidepressants which impair the capacities without reducing the desire. Despite the specific side effects on some instinctive functions, lithium seems to be a treatment well lived by the subjects.