Know of a couple. One I went to middle school with and lost touch with her upon entering high school. Last I heard she killed herself after recently being reinstated, which was ironic to me because all the years I knew her she was an exemplary young JW. Something changed during her high school years and her mid early twenties. Family and friends from what I gather never seen it coming.
Another was an elder who was removed. As a teen and a young man I loved him, very cool, very down to earth guy. Always wanting to wrestle and slap-box when he would see me. Type of guy you loved watching the game with, or even working on maitenance issues at the KH. A man's man. Behind closed doors though, not someone you could respect. It didn't surprise me that much when he killed himself.
Another young man I knew, died in an accident, but behind the scenes more than a few people have questioned that. I've never expressed it to anyone that I share those sentiments as there's really no proof, and really what good would it do anyway. Very smart young man, to the point of not fitting in with other JWs, or nonJWs. When he died, it both surprised me, and yet it didn't surprise me if that makes any sense.
Know a handful of JWs that have either attempted suicide, or mentioned that they're suicidal as well.