Examining the recent medical history of suicide victims, researchers in Finland found a strong association between abortion and suicide. In their findings, published in the British Medical Journal (Mika Gissler, Elina Hemminki, Jouko Lonnqvist, "Suicides after pregnancy in Finland: 1987-94: register linkage study" British Medical Journal 313:1431-4, 1996) they report that "The suicide rate after an abortion was three times the general suicide rate and six times that associated with birth." 

These findings are consistent with previous studies that have found that giving birth reduces the risk of suicide compared to the "normal" population while abortion increases the risk of suicide. Unfortunately, this study looked for an abortion only in the one year before the suicide. Because most women report a delayed post-abortion reaction, it is very possible that most abortion related suicides would occur in subsequent years.