MOrpheus If you only knew one suicide in however many years in a big city I would say you were very lucky. Check out the exjw reddit sub - we get postings grieving the death of friends ( accompanied with newspaper articles often) every few weeks. They tend to be young, tragically, and stuck in (Pimo) or DF and shunned.
Perhaps you are right, some of these people would have suffered depression anyway, JW or not .Perhaps the statistics for jw's are the same as for the General population. But I would say two things to you.
1) control has increased over the years
2) shunning has increased, too
This has made things worse since your day