anxiogenic

adjective

an·​xi·​o·​gen·​ic ˌaŋ-zē-ō-ˈje-nik, ˌaŋ(k)-sē- 

: producing anxiety

… giving up smoking is quite rapidly followed by a reduction in anxiety that may reflect removal of an anxiogenic agent, nicotine.

—Robert West and Peter Hajek, The American Journal of Psychiatry

anxiogenic noun

… the qualitative effects of stressors and anxiogenics …

—Craig W. Berridge et al., in The Asymmetrical Brain