The 13th Floor Elevators frontman will return with his first album of original songs in more than a decade. And he's hired Austin indie-rockers Okkervil River as his backing band

13th Floor Elevators' Roky Erickson will return with his first album of original material in 14 years, recorded with Austin indie-rockers Okkervil River. True Love Cast Out All Evil includes material written throughout Erickson's life and "found sounds" from the Rusk State Hospital for the Criminally Insane, where he spent several years in the early 1970s.

"This is not a cynical comeback record, a lukewarm update on an established legacy – these are the best songs Roky has ever written," claims Okkervil River's Will Sheff, who produced the album. "This record has been the most challenging and rewarding thing I've ever worked on, and we in Okkervil River were deeply honoured to show up decades later and help Roky carry these wonderful songs over the finish line."

Though his music has appeared in several anthologies over the last two decades, Erickson has not released new material since 1995's All That May Do My Rhyme, and it is half a century since the Texas songwriter's most celebrated work, with psychedelic rockers 13th Floor Elevators. Erickson was diagnosed with paranoid schizophrenia in 1968, leading to time in hospital, while minor skirmishes with the law resulted in further hospitalisation – including electric shock therapy.

In the decades that followed, Erickson gained legendary status, bolstered (and weighed down) by his reputation as an "outsider" artist. He has been saluted by acts including REM, Primal Scream, the Jesus and Mary Chain, ZZ Top and even Kasabian. In 2005 the singer was profiled in a documentary, You're Gonna Miss Me, which helped a healthier Erickson to launch a small comeback, touring the US and Europe.

Okkervil River play on all of the new album, which is drawn from among 60 unreleased Erickson songs. "[These tracks went] unreleased due to decades plagued by the kind of personal tragedies that would destroy someone less resilient," Sheff said. "There were songs written during business setbacks including the Elevators' painful break-up, songs written by Roky while he was incarcerated at Rusk, and a great deal of songs that reminded me of the sense of optimism and romanticism that I think sustained Roky through his worst years and ultimately reunited him, a few years ago, with his son Jegar and his first wife Dana ... The quality of the material we ended up with was exhilarating."

True Love Cast Out All Evil will be released by Anti on 20 April.