On the occasion of his 100th birthday this letter is to pay tribute to Swiss psychiatrist and psychopharmacologist Roland Kuhn (1912–2005), who established the antidepressant effects of imipramine starting in 1956. Since until now only monoaminergic-based antidepressants such as this substance found their way into psychopharmacological therapy, one can say that Kuhn established the lead antidepressant substance and has hence fundamentally changed clinical psychiatry and care for the mentally ill.