Police are looking for Dominic Berger, a 31-year-old man, who has been missing since Thursday morning.
An ACT Policing spokesperson said he was last seen about 10.30am on August 22 in the city CBD area.
He was described as Caucasian in appearance, about 180cm (5'11") tall, with a slim build, fair complexion, blue eyes, and shoulder length light brown hair.
"Dominic was last seen wearing green cargo pants, a dark coloured jumper, and grey shoes," police said.
Police also said he was suffering from "a decline in his mental health" and that his family were concerned about his wellbeing.
Police appealed to the public for help to find the 31-year-old.
Anyone who had seen Dominic, or who had any information regarding his whereabouts was urged to contact ACT Policing on 131 444. They are requested quote reference number 7830976. Police said information could be provided anonymously.