Disturbing findings about the risk of suicide and psychiatric hospitals.

Comments on an article by C. R. Hjorthøj et al. (see record 2014-35908-002). The study, by Hjorthøj and associates, is a nested case– control study that compared Danish residents who died by suicide between 1996 and 2009 with living age-, sex- and year-matched controls. The authors describe the relationship between suicide and the extent of psychiatric treatment in the previous year. The study found that, compared to those who had no psychiatric treatment in the previous year and after adjustment for other risk factors: those who only received psychiatric medication had 5.8 times the risk of suicide; those with at most outpatient psychiatrist treatment had 8.2 times the risk of suicide; non-admitted patients who had contact with emergency departments had 27.9 times the risk of suicide; and admitted patients had 44.3 times the risk of suicide. Particularly striking are the strength of the associations between emergency room treatment. The Hjorthøj study demonstrated a statistically strong and dose-dependent relationship between the extent of psychiatric treatment and the probability of suicide. This relationship is stepwise, with significant increases in suicide risk occurring with increasing levels of psychiatric treatment. The authors understandably caution that ‘‘the association is likely one of selection (rather than causation), in that people with increasing levels of psychiatric contact also are more severely at risk of dying from suicide”. This is undoubtedly part of the reason for the association, but it is not possible to be sure that an element of causation may not also be contributing.