Back at the start of the 1980's, Haircut One Hundred were, for about a year, one of the biggest bands in the UK. Their debut LP "Pelican West" sold like hot cakes, and they toured and did TV appearances everywhere. Then, suddenly, Nick Heyward, the principal songwriter, quit the band. Absent a strong songwriting presence, Haircut staggered on for a couple more years, then disbanded. Heyward started a solo career, which started promisingly, then stalled out, then he too disappeared for a while, before resuming what is an uneven solo career.
Now, some of the inside story on the Haircut One Hundred split is laid bare in this article. What is clear from the article is that Heyward's decision to leave the band was largely caused by depression, which has been a constant factor in his life.