The invention concerns compounds that possess a high affinity at 5-HT1A receptors and an agonist efficacy, as measured by Emax values from a cellular activation assay, that is higher than that of the compounds described in prior art. The capacity of the compounds of the invention to activate an effector protein complex is higher than that the most efficacious agonist described in prior art. Compounds of the invention also exhibit an exceptionally high selectivity (Ki ratio greater than 1000-fold) with respect, in particular, to dopamine D2 receptors and adrenergic receptors of the alpha1 subtype. This selectivity which constitutes a great advantage since it means that the compounds will avoid inducing (central and peripheral) effects associated with activating or inhibiting such receptors