[3] Gustav Simon remained a practicing physician in Berlin but continued to work on scientific publications.
[7][8] In 1848 Simon was appointed director of the Department of Skin Diseases and Syphilis at the Charité hospital in Berlin.
His normally composed personality gave way to irritability, aggression and confusion, leading to his removal from the departmental directorship at the Charité,[11] being replaced by Felix von Bärensprung.
The nature of the disease was not yet understood and his subsequent stays in sanatoriums in Potsdam, Eberswalde, and Leubus brought no improvement to his condition.
[10] Gustav Simon died in 1857 in the Schweizerhof Nerve Clinic founded by Heinrich Laehr in Berlin's Zehlendorf district.