The 21-year-old singer from Nesseby said that her mental health is struggling in the run-up to the contest in Stockholm and has pulled out of all national and international activities, including interviews and concerts.
"I appreciate the interest in my participation in Eurovision but right now my only focus is to do what I love most – signing on stage. I hope people can understand that I need to do that now," she told broadcaster NRK.
Johnsen, whose song 'Icebreaker' won Norway's national competition in February, said that she has long battled depression and suicidal thoughts.
“For many years, I have been struggling mentally and I can't always control my thoughts as mush as I'd like to. When it happens, I am not capable of thinking positive and I will mentally go to a very dark place," Johnsen told VG.
"Everything is just negative. A pure hell," she added.
Johnsen said she hopes that pulling out of the promotional events in Stockholm ahead of the big show will allow her to focus on her performance.
According to her managers, Stein Vanebo and Espen Nystad, the singer's decision to focus on her mental health ahead of the contest has the full support of the Norwegian delegation.
"All of us who are going to Stockholm are united in giving her all the support she needs to bring the victory home. And let there be no doubt – Agnete is competing to win Eurovision," they said in a statement to NRK.
Johnsen will perform 'Icebreaker' in the second semi-final of the Eurovision Song Contest on May 12th in Stockholm. The final round is on May 14th.