American men are four times more likely than women to take their own lives. It's a troubling phenomenon, rooted in such factors as genetics, upbringing and even career choice. But a growing body of research suggests that divorce is one of the major culprits in suicides among adult males..
Women, however, seem immune to the stress and sadness that can be wrought by the end of a marriage.[...]
Denney's* research, published last year in Social Science Quarterly, concluded that men who are divorced are 39 percent more likely to commit suicide than those still married. The difference increases to 50 percent when a man is a widow.
Among women, differences in suicide risk among those who were married, divorced or widowed were statistically insignificant. [...]
And while married women often balance employment with child rearing, Denney said statistics suggest they're coping quite well. "Women remain the primary caretakers in most households," he said. "They're working more, yet feeling better."
That might be what explains a divorced or widowed woman's relatively low suicide risk. Denney's subsequent research, published in February's Journal of Marriage and Family, concluded that children offered a major protective effect against suicide. For each additional child in a household, adults were 6 percent less likely to commit suicide
*Dr. Justin Denney, a sociologist at the University of Colorado
The studies by Denney:
Denney, J. T., Rogers, R. G., Krueger, P. M. and Wadsworth, T. (2009), Adult Suicide Mortality in the United States: Marital Status, Family Size, Socioeconomic Status, and Differences by Sex. Social Science Quarterly, 90: 1167–1185. doi: 10.1111/j.1540-6237.2009.00652.x
Objective. This article addresses the relationship between suicide mortality and family structure and socioeconomic status for U.S. adult men and women.
Methods. We use Cox proportional hazard models and individual-level, prospective data from the National Health Interview Survey Linked Mortality File (1986–2002) to examine adult suicide mortality.
Results. Larger families and employment are associated with lower risks of suicide for both men and women. Low levels of education or being divorced or separated, widowed, or never married are associated with increased risks of suicide among men, but not among women.
Conclusions. We find important sex differences in the relationship between suicide mortality and marital status and education. Future suicide research should use both aggregate and individual-level data and recognize important sex differences in the relationship between risk factors and suicide mortality—a central cause of preventable death in the United States.
Denney, J. T. (2010), Family and Household Formations and Suicide in the United States. Journal of Marriage and Family, 72: 202–213. doi: 10.1111/j.1741-3737.2009.00692.x
Family support systems have been theoretically linked to suicide risk. But no research to date has investigated the effects of detailed living arrangements on individual risk of suicide. Using data on 825,462 adults from the National Health Interview Survey Linked Mortality File reveals that living in families with stronger sources of social support and integration decreases risk of suicide. These effects persist despite controls for important individual level characteristics. Risk of suicide decreases for persons in married as well as unmarried families when children are present and risk increases for persons living with unrelated adults. These results reveal the structural importance of family formation on the social integrative forces that contribute to an individual's risk of suicide.
The UK Study mentioned in the article:
Suicide rates in young men in England and Wales in the 21st century: time trend study - BMJ 2008 - Lucy Biddle, Anita Brock, Sara T Brookes, David Gunnell
Objectives To explore trends in suicide in young people to investigate the recent observation that after year on year rises in the 1970s, 1980s, and early 1990s, rates in young men are now declining.
Design Time trend analysis.
Setting England and Wales, 1968-2005.
Population Men and women aged 15-34 years.
One of the most striking features of the epidemiology of suicide in the late 20th century was the epidemic rise in suicide among young men in most industrialised nations.1 From 1950 to 1998 in England and Wales, rates of suicide in men aged under 45 doubled, while rates in women and older men declined.2 During the 1990s, rates in young men aged 15-24 reached an all time high and were at their highest since the 1920s in men aged 25-34 years. Suicide accounted for about a fifth of all deaths in young men,3 and men aged 25-34 had the highest rate of all age-sex groups.2 Such trends have led to suicide becoming a major contributor to premature mortality4 and are thought to indicate deteriorating mental wellbeing in younger people.
The cause for these rises is uncertain, though time series data show parallel increases in a range of risk factors including unemployment, divorce, substance misuse, and income inequality.2 Furthermore, changes in the availability and use of common methods of suicide, particularly domestic gas, barbiturates, and motor vehicle exhaust gases, have had an important impact on suicide rates and trends in the past 50 years.5 6 7 [...]
With the exception of the marked increase in divorces in 1972 after the Divorce Reform Act 1969 came into effect, rates of divorce closely followed trends in suicide in young men at the end of the 20th century. Both increased into the 1990s and then showed a decline up to 2001 (fig 2)⇓. Unlike the trends seen for suicide, however, divorce rates increased from 2001 to 2004 but have since fallen once more.
And finally a huge article on suicide:
Suicide - The Epidemiology Of Suicide
Marital status has a strong association with rates of completed suicide. Suicide rates are higher in the divorced and widowed than in single people, who in turn have higher suicide rates than married people. This protective effect of marriage on suicide is stronger for men than for women, although it is found for both men and women (Gove 1972).
The strong association of divorce with suicide is found at the societal level as well as at the individual level. For example, nations with higher divorce rates have higher suicide rates, U.S. states with higher divorce rates have higher suicide rates and, within nations, years with higher divorce rates have higher suicide rates. This association is probably the most robust association found in suicidology. The associations between marriage rates and suicide rates and between birth rates and suicide rates are not as consistent, although they do tend to be negative associations more often than positive associations.
[...] Christopher Cantor and Penelope Slater (1995) found that the suicide rate in Queensland, Australia, was highest for men who were separated, as opposed to men who were single, married, divorced, or widowed. For women, the divorced had the highest suicide rate. The increase in the suicide rate in separated men was greater in those who were younger (age 15–19) than in those who were older (over the age of 55). These results suggest that the time during the breakdown in the marriage may be more stressful for men than for women, whereas the state of divorce may be stressful for both men and women.
The higher rate of suicide in widows as compared to those married of the same may be because bereavement increases the risk of suicide or because widows and widowers who are prone to suicide are less likely to get remarried. Some old data from Brian MacMahon and Thomas Pugh (1965) indicate that it is bereavement—and not differential remarriage rates—that is the factor responsible. However, research (for example, a study by Arne Mastekaasa  in Norway) also indicates that, once age is taken into account, the higher suicide rate in the widowed as compared to the divorced is no longer found.
Even though those who are married have lower suicide rates than those in other marital statuses, Walter Gove (1972) has documented that marriage is more beneficial for men than for women, in that the reduction in the suicide rate (and also in rates of psychiatric disturbance) is greater for married men than for married women.
The presence of children appears to have a protective effect with regard to suicide. In a study of a large sample of women in Norway, Georg Hoyer and Eiliv Lund (1993) obtained a sample of almost one million single and married women in Norway in 1970 and identified which of them had completed suicide by 1985. They found that unmarried women had a higher suicide rate than married women without children for those aged twenty-five to sixty-four, but not for those over the age of sixty-four. Thus, marriage appeared to reduce the suicide rate in women.
Hoyer and Lund also found that married women with children had lower suicide rates than married women with no children for all age groups. Thus, the presence of children further reduces the risk of suicide in women above and beyond the protective impact of marriage per se. Furthermore, the more children, the lower the suicide rate of the married women.
This study is the best study on the topic reported hitherto, but it confirms the results of earlier studies on smaller samples and without such detailed analyses. For example, in Portugal women with children were found to have a lower suicide rate than childless women, and those with more than five children had the lowest suicide rate (de Castro and Martins 1987).
There is also some evidence that the presence of children reduces the severity of suicidality in suicidal women, for example, making attempted suicide relatively less common and suicidal ideation relatively more common.
And while we are at it, google scholar provided me also with:
Marital status and suicide in the National Longitudinal Mortality Study - Augustine J Kposowa - 1999
OBJECTIVES The purpose of the study was to examine the effect of marital status on the risk of suicide, using a large nationally representative sample. A related objective was to investigate the association between marital status and suicide by sex.
METHODS Cox proportional hazards regression models were applied to data from the National Longitudinal Mortality Study, based on the 1979–1989 follow up. In estimating the effect of marital status, adjustments were made for age, sex, race, education, family income, and region of residence.
RESULTS For the entire sample, higher risks of suicide were found in divorced than in married persons. Divorced and separated persons were over twice as likely to commit suicide as married persons (RR=2.08, 95% confidence intervals (95% CI) 1.58, 2.72). Being single or widowed had no significant effect on suicide risk. When data were stratified by sex, it was observed that the risk of suicide among divorced men was over twice that of married men (RR=2.38, CI 1.77, 3.20). Among women, however, there were no statistically significant differentials in the risk of suicide by marital status categories.
CONCLUSIONS Marital status, especially divorce, has strong net effect on mortality from suicide, but only among men. The study showed that in epidemiological research on suicide, more accurate results would be obtained if samples are stratified on the basis of key demographic or social characteristics. The study further observed that failure to control for relevant socioeconomic variables or combining men and women in the same models could produce misleading results. [...]
Data analysis revealed that marital status is associated with the risk of suicide, and that divorce and separation have the strongest association. Indeed, when adjustments were made for such potential confounders as age, race, education, income, and region of residence, divorce/separation was the only status category that showed a significant increased risk of suicide. [...]
Results have also shown that while marital status, especially divorce increases the risk of suicide in men, the same cannot be said of women. In other words, the effect of marital status on suicide depends on sex. One possible explanation for the observed differentials by sex is that perhaps women form greater supportive networks, such as meaningful friendships at a higher level than men, and regardless of their marital status. Accordingly, even if a marriage ends in divorce or widowhood, women can fall back on their friendship networks for emotional and social support. It may be that men form less meaningful and fruitful supportive social bonds and networks. Accordingly, when a marriage breaks, men have no safety net. [...]
It is important to note that socioeconomic status affects men and women differently in terms of suicide risk. Low educational attainment and income are significant risk factors for men, but not for women.