"The results led us to say that the so-called β-down-regulation is not (as it was believed in the 1970s and 1980s) a necessary and characteristic condition for the antidepressant action of drugs. In particular, this confirmed the result that citalopram, currently considered the most effective antidepressant from the group of selective serotonin inhibitors, does not cause β-down regulation, and the opposite effect. Jurek was completely not bothered by the fact that these results had narrowed down the earlier theory (his and Sulser's) regarding the mechanism of action of antidepressants. He believed, and often said, that a true scholar can not fall in love with his own theories and must know that sometimes they should be verified."