Common risk factors for abortion and suicide attempts

In the field of abortion and mental health research, few studies have focused on suicide attempts. The study of Julia R Steinberg and colleagues 1 in The Lancet Psychiatry is based on an impressively large, bias-free, real-world registry dataset, and is a welcome addition to the academic literature. Steinberg and colleagues correctly limit their analyses to first-time abortions and first-time suicide attempts; although this decreases external validity, it is a necessary step to establish causal effects and ensure temporal order. However, the fact that the data are based on registries also poses some limitations to the interpretation of the results; furthermore, their findings do raise an important question. The results suggest that the abortion itself was not the reason for the increased risk of suicide attempts, but that one or more unmeasured variables contributed to it. Obviously, Steinberg and colleagues 1 could not capture what these co-occurring variables might have been. If the increased risk was not due to the abortion itself, then why was the risk higher in women who had an abortion the year before and after the abortion, relative to more than one year after the abortion?