At least the mystery where the song comes from and whether it has to do with Jared Letho from 30SecondsToMars is solved by Pete himself by now:
"... Among the more interesting tracks is the closing "Leto's Headache," which was written for 2009's Sci-Fi Crimes and inspired by time spent hanging out with Thirty Seconds to Mars frontman and Academy Award winner Jared Leto and his drummer brother Shannon.
"We had a good friendship for awhile," Loeffler says. "The song just kind of touches on what I saw when I'm around him and how his fame grew so rapidly that...it's hard for him to go out and all that. He has a famous headache, so I wrote about that." ..."
At least the mystery where the song comes from and whether it has to do with Jared Letho from 30SecondsToMars is solved by Pete himself by now:
"... Among the more interesting tracks is the closing "Leto's Headache," which was written for 2009's Sci-Fi Crimes and inspired by time spent hanging out with Thirty Seconds to Mars frontman and Academy Award winner Jared Leto and his drummer brother Shannon.
"We had a good friendship for awhile," Loeffler says. "The song just kind of touches on what I saw when I'm around him and how his fame grew so rapidly that...it's hard for him to go out and all that. He has a famous headache, so I wrote about that." ..."
Source: https://www.billboard.com/articles/columns/rock/8480583/chevelle-12-bloody-spies-album