DD received honoraria for services provided to Allergan, Ipsen, Merz, Lanzhou Institute of Biological Products, Medy-Tox, Revance, Gufic, WizMedi, Shionogi, Desitin, Syntaxin, Allergan-Abbvie, Medtronic, St Jude, Boston Scientific, Almirall, Bayer, Sun, Teva, UCB, IAB-Interdisciplinary Working Group for Movement Disorders. He is shareholder of AbbVie and holds patents on botulinum toxin and botulinum toxin therapy. He provides professional consulting services to pharmaceutical companies and professional investment institutions on all aspects of botulinum toxin drugs. He is co-founder and member of the board of directors of Wisper Bio and founder of The Wittgenstein Organisation.