LOS ANGELES- Selena Gomez will make her comeback on the Julia Michaels song 'Anxiety'.

The 26-year-old pop star's first new music since she checked into rehab in October, after suffering an ''emotional breakdown'' following multiple hospitalisations due to issues related to Lupus and her kidney transplant, will be a feature on the track from the 25-year-old star's upcoming EP 'Inner Monologue Part I', which is released on Friday.

The EP also features One Direction's Niall Horan on closing track 'What A Time'.

Julia has helped compose hits for the likes of Ed Sheeran, Rita Ora and Janelle Monae in the past, but admitted she was feeling ''more nervous'' than ever about the release of her impending mini album.

Alongside the artwork posted on her Instagram account, she wrote: ''inner monologue part 1 out January 25th. But here's a piece of my mind and my heart. It’s yours next week.''

Though 'Wolves' hit maker Selena is yet to comment on the track, Niall, 25, took to Twitter to reveal his excitement at getting to work with the 'Issues' hit maker, and teased their duet is ''stunning''.

He wrote: ''So excited about this! I'm singing on Julia michaels album and I'm over the moon. Julia is one of my very very good friends and 'what a time' is absolutely stunning. I'm very proud to be part of this and can't wait for you guys to hear it.'' 'Inner Monologue Part I' is Julia's fourth EP, her second on Republic Records, and follows 2017's 'Nervous System'.