[New vistas on rubidium]

Rubidium salts have been used in human therapy since the end of the last century. The fact that an actual use in psychiatry has been considered is mainly due to Meltzer and al's works in 1969. The pharmacological studies do not reveal any psychopharmacological "provile" presently known; they point out that Rubidium has stimulant properties, whick, in certain conditions, can increase activity, central excitability and sometimes aggressiveness, among the animals used for the experiments. The hypothesis of a contingent antidepressant action of Rubidium is essentially based on the existence of properties opposite to those of Lithium. This is especially true in the biochemical field: Rubidium may enhance the release of Norepinephrine whereas Lithium has an opposite effect. The toxicological studies show that, because of some properties common to Rubidium and Potassium, it is necessary to control Potassium intake and to avoid that Rubidium replace too high a percentage of this ion: the extended half-life (about forty days in man) makes necessary the working up of chronical studies to evaluate the toxicity which is linked to its long-term accumulation. For Rubidium blood concentrations superior to 1 mEq/1., the first clinical studies seem to point out that an antidepressant action would exist. Nevertheless a certain delay of action is necessary to the onset of a therapeutic effect; no noticeable adverse effect has been detected.