I think this could belong to the 'urban legend' category.

Below is a portion of an article available at Jobs Rank Low As Risk Factors For Suicide - New York Times


"Urban legend notwithstanding, the relationship between suicide and occupation is far from clear-cut, experts say, and what someone does for a living does not say much about the potential for suicide.

''There is a lot of fantasy out there amidst the reality,'' said Dr. Roger E. Alexander, a professor at the Baylor College of Dentistry, who last year called into question the common notion that dentists were highly suicidal.

Dr. Ronald Maris, a forensic suicide expert in Columbia, S.C., said he had compiled a list of 15 major suicide predictors. ''And none of them concerns occupation,'' he said. "

When I did a search of this subject I kept finding conflicting information. It seems to be difficult to find credible data on this topic.