I gave this some thought, and though I only know of one suicide, there were several attempts.
In the 70's: K.'s Mom became a JW when K. was 14. Her mom was a blunt, independent single working mom, which meant the family was on the low rung of the social ladder at the KH. Few invitiations were issued to that family and they became isolated. At age 16, K. tried to overdose on pills because of the isolation and because her mom wasn't letting her do normal teenage things with 'worldly' kids. Fortunately her sister found found her in time and K. made it through. None of the family are JWs today.
Also in the 70's: R. was raised by a JW mom. R. was never baptized, but still felt very guilty for fornicating. She had an abortion which pushed her over the edge, and she also overdosed on pills. Her mother found her and took her to the hospital. Fortunately R. made it through. At her hospital bedside, her mother, being a typical judging JW, condemned her to die at Armageddon because of her suicide attempt.
In the 80's: After I moved away from home, I ended up going to a congregation that was very cold. Since I wasn't a pioneer, had a college degree, a professional job and a sports car, I was marked as spiritually weak. I had no friends in the cong. My family of JWs didn't bother calling either. Feeling lonely and unloved, I started dating a 'worldly' guy and nature took it's course. I then felt very guilty. One night out of desperation I decided to end it. I looked in the medicine cabinet, and all I had were 8 aspirins. Not enough to do the job. I looked at cleaning supplies and read the labels to see what the effects of ingestion would be. At that point I chickened out because I don't like pain. I knew the most painless method was carbon monoxide poisoning. If I had a garage back then, I'd be dead today.
In the 90's: J. was injured on the job. His injuries forced him to go on disability and move back home with his family in his late 30's. He felt like a failure as a man and he felt like a failure as a JW. Booze was his companion as he blew his brains out. R.I.P. J.