In mid-2005, Decapitated's vocalist
Wojciech "Sauron" Wąsowicz departed from the band and was replaced by
Adrian "Covan" Kowanek.
Organic Hallucinosis was recorded in August 2005 at Hertz Studio in
Białystok, Poland with producers Slawek and Wojtek Wiesławski and features artwork and layout by
Spiros Antoniou (Seth). The album was released by
Earache Records on 7 February 2006 in the United States and on 13 February internationally. A music video was filmed for the song "Day 69" and released that year. A limited edition of 1000 bonus CDs were given away for free by
Earache Records for people who purchased
Organic Hallucinosis in United Kingdom independent stores. It contains tracks from live at
Earache Christmas party, Rescue Rooms,
Nottingham, 20 December 2004. A Japanese edition was released by
Teichiku Records, which contains live bonus tracks taken from the same recording as the bonus CD. The album's release was followed by a headlining European tour starting in September 2006 In November, Decapitated's tour bus was involved in an automobile accident in Belarus that killed drummer
Witold "Vitek" Kiełtyka at the age of 23 and seriously injured Covan. The band's guitarist
Wacław "Vogg" Kiełtyka announced an indefinite hiatus. == Critical reception ==