Botulinum toxin overrides depression: not surprising, yet sensational.

Some 5 years ago we have filed a patent application on treating depression with BTx (German Patent Office; 2001) and thought of this as literally mind blowing and radically innovative. Yet, the link between corrugator muscle activity (frowning) and emotional status has fascinated the scientific community for centuries: Charles Darwin was convinced that the corrugator muscle had a tremendous impact on emotional expression, which he considered a driving force for human evolution. He dedicated a whole book to his observation of ‘‘the expression of the emotions in man and animals.’’ Photographs of intense facial expressions illustrated the book as a real novelty in scientific publishing at that time.