(AP) — A new study says gay and bisexual teen boys use illicit steroids at a rate almost six times higher than do straight kids.

The authors say that dramatic disparity highlights a need to reach out to this group.

Overall, 21 percent of gay or bisexual boys said they had ever used steroids. That’s versus 4 percent of straight boys. Eight percent of gay or bi teens, and less than 2 percent of straight kids, reported taking steroid pills or injections up to 40 times.

Reasons for the differences are unclear. The study authors said it’s possible gay and bi boys feel more pressure to achieve a bulked-up “ideal” male physique, or that they think muscle-building steroids will help them fend off bullies.

Their research was released Monday in the journal Pediatrics.