On this site:
https://www.hant.se/noje/sa-gick-det-sen-for-skadespelarna-i-filmen-fucking-amal/7224981 I found a part in which Mathias, Stefan's friend, comments on the life and death of his friend Stefan, I have translated that part:
"They both kept in touch almost until the end.
- It was really terrible, what happened. But he wasn't feeling well, had quite big problems with substance abuse and so on. I think, unfortunately, that he had never been really well, not when he was younger either. Why I don't really understand, because he had a good upbringing with parents who loved him. His father asked me to call Stefan sometimes when he was hard to reach.
Did you notice during the shooting of the film that he was not feeling well?
- No, during the Fucking Åmål recording, I think he was at his very best.
How do you remember Stefan?
- Stefan was a great guy, happy, handsome and fun-loving. I remember that during the recording of Fucking Åmål he always joked with the guys on sound. He would always put the mic on when they asked us to turn it off, then he would go whispering, breathing and making noises in the mic so they would be completely confused and say "where is that noise coming from?" It was hilarious, he laughed like hell at it.
Hänt has been in contact with Stefan's relatives, who think it's okay to write about him, but they don't want to leave any comments."