Because of the high number of therapy-resistant depressions and the growing number of suicides, there is still a great need for the development of antidepressants with a new pharmacological spectrum. The finding that phenylethylamine and tryptamine are endogenous enhancers of the impulse propagation mediated release of catecholamines and serotonin in the brain, and the development of synthetic enhancer substances opened the possibility to stimulate catecholaminergic and serotonergic neurons in the brain stem via a previously unknown mechanism. (-)-Deprenyl, a prototype of the phenylethylamine-derived synthetic enhancer substances, stimulates the catecholaminergic neurons in the brain but is almost ineffective on the serotonergic neurons. R-(-)-1-(benzofuran-2-yl)-2-propylaminopentane, (-)-BPAP, the recently developed tryptamine-derived selective synthetic enhancer substance, is a hundred times more potent enhancer of the catecholaminergic neuronal activity than (-)-deprenyl, and is also a highly potent stimulant of the serotonergic neurons. Evaluation of the peculiar pharmacological profile, the high potency and unusual safeness and tolerability of (-)-BPAP cherish the hope that this compound by itself and in combination with uptake inhibitors may improve the effectiveness of drug therapy in major depression and diminish the number of therapy resistant cases.